HacDC Wiki - User contributions [en]

Cheap Chinese Laser

2017-06-27T03:27:22Z

James: 6/22 update

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch (power strip inside the wooden cabinet)
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch

===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [http://192.168.26.122:8000/ 192.168.26.122 Port 8000] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#12VDC / Cutting Chamber LED positive
#Hour meter / 12VDC / Cutting Chamber LED ground
#Hour meter positive
#Laser fire switch positive - shorts to ground (below) to fire laser
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|-
| Unsuccessful work to connect hour meter. || James || 6/11/17 || Don't use laser for now. I'm waiting on some parts to make a soldered accessory board.
|-
| Strip boards arrived and I fabbed a circuit card to control the power, fire the laser, and drive the hour meter. It still needs to be connected and tested. || James || 6/17/17 || Don't use laser for now. Accessory board needs testing.
|-
| After several rounds of testing, the problem with the board is still undetermined. SSRs might be fried. Tom is researching bulk buy. Thanks, Tom.|| James || 6/22/17 || Laser only works with manual fire and power control.
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-19T04:42:06Z

James: 6-17 update

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch (power strip inside the wooden cabinet)
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch

===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [http://192.168.26.122:8000/ 192.168.26.122 Port 8000] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#12VDC / Cutting Chamber LED positive
#Hour meter / 12VDC / Cutting Chamber LED ground
#Hour meter positive
#Laser fire switch positive - shorts to ground (below) to fire laser
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|-
| Unsuccessful work to connect hour meter. || James || 6/11/17 || Don't use laser for now. I'm waiting on some parts to make a soldered accessory board.
|-
| Strip boards arrived and I fabbed a circuit card to control the power, fire the laser, and drive the hour meter. It still needs to be connected and tested. || James || 6/17/17 || Don't use laser for now. Accessory board needs testing.
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-12T00:18:34Z

James: added 6/11 work on hour meter.

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [http://192.168.26.122:8000/ 192.168.26.122 Port 8000] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#12VDC / Cutting Chamber LED positive
#Hour meter / 12VDC / Cutting Chamber LED ground
#Hour meter positive
#Laser fire switch positive - shorts to ground (below) to fire laser
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|-
| Unsuccessful work to connect hour meter. || James || 6/11/17 || Don't use laser for now. I'm waiting on some parts to make a soldered accessory board.
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-11T21:53:58Z

James: added +12VDC terminals to block connection list for LEDs, hour meter, and power supply

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [http://192.168.26.122:8000/ 192.168.26.122 Port 8000] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#12VDC / Cutting Chamber LED positive
#Hour meter / 12VDC / Cutting Chamber LED ground
#Hour meter positive
#Laser fire switch positive - shorts to ground (below) to fire laser
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-09T02:21:12Z

James: fixed link text for LaserWeb server

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [http://192.168.26.122:8000/ 192.168.26.122 Port 8000] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#Laser fire switch 1
#Laser fire switch 2 - one of these is the same as power level GND (immediately below)
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-09T02:17:44Z

James: removed tool path creation step. it gets done later.

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [[http://192.168.26.122:8000/]] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#Laser fire switch 1
#Laser fire switch 2 - one of these is the same as power level GND (immediately below)
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-09T01:50:46Z

James: clean up of links in Operations section and successful fully automatic operations recorded

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [[http://192.168.26.122:8000/]] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [[file:Laserweb-settings-backup.json]] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#Laser fire switch 1
#Laser fire switch 2 - one of these is the same as power level GND (immediately below)
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|-
| Test fire was successful. Operations section updated. || James || 6/8/17 || Fully automatic operations achieved!
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-09T01:31:12Z

James: added step-by-step instructions for software use

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
##You can skip this step for now since the lights don't work
#Do software stuff
##Connect to LaserWeb server at [http://192.168.26.122:8000/] from HacDC network
##Clear LaserWeb 4 upgrade warning popup
##Click on Settings on left edge of page
##Click on BACKUP at top of setting pane
##Click on Restore from file
##Upload [file:Laserweb-settings-backup.json] file
##Click Save
##Observe messages "Saved Settings" and "Please refresh page for settings to take effect"
##Refresh webpage
##Clear LaserWeb 4 upgrade warning popup, again
##Load SVG file of cutting paths by dragging and dropping into the web browser window
##Click Generate G-Code (on CAM menu)
##Click Connect at the top of the webpage
##If a popup appears, choose Option 1
##Click Jog on left edge of the window
##Click home and observe the gantry move to the home position in the far left corner of the cutting chamber
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
##Click check outline and observe the laser move
###Check that material is fully under the travel area
###Check that your design is the size you expect it to be (25.4 for mm)
###If the size is not right, go to the Settings page and adjust the DPI setting on the Size menu
#Run program with laser powered on to cut material
##Click run gcode
##Watch for things catching fire

===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#Laser fire switch 1
#Laser fire switch 2 - one of these is the same as power level GND (immediately below)
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

File:Laserweb-settings-backup.json

2017-06-09T00:33:18Z

James: Laserweb-settings-backup.json Settings file for laser cutter. Uploaded 6-8-17

Laserweb-settings-backup.json
Settings file for laser cutter.
Uploaded 6-8-17

Cheap Chinese Laser

2017-06-08T04:08:26Z

James: added local address for laserweb server

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#Laser fire switch 1
#Laser fire switch 2 - one of these is the same as power level GND (immediately below)
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || [http://192.168.26.122:8000/ Laserweb server], from HacDC network
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-06-07T17:14:12Z

James: added Addition Reading section, updated work done on 6/4 - 6/6, added terminal block info for fire switch

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#Laser fire switch 1
#Laser fire switch 2 - one of these is the same as power level GND (immediately below)
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || James + Tom || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || James + Tom || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || James + Tom || 5/28/17 || We've got some stray AC current in the case.
|-
| Installed RasPI as webhost. Replaced USB cable. || James + Tom || 6/4/17 || URL goes here.
|-
| Test cut Pepe the frog on opaque acrylic with painters tape mask. || James + [[user:Andrew|Andrew]] || 6/5/17 || Auto fire signal still isn't working.
|-
| Added circuitry to breadboard to automate the firing signal. || James || 6/6/17 || Will test on Thursday.
|}

==Additional Reading==
#[http://howell.seattle.wa.us/essays/lasercutter.shtml Laser blog]
#[https://www.reddit.com/r/lasercutting/wiki/k40 Reddit K40 wiki]
#[http://www.lightobject.com/Default.aspx Light Object laser retailer]

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-30T23:56:08Z

James: listed 12V accessory power supply as installed component

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the 12V accessory power supply, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (marginal one installed currently to power the cutting chamber accessory lights).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#
#
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || Tom & James || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || Tom and James || 5/28/17 || We've got some stray AC current in the case.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-30T23:51:04Z

James: listed door switches remaining to be installed. removed terminal block install, since it's done.

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#
#
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##Cabinet door
##Laser tube chamber door
#Chassis wiring
##Wire up the safety switches as they are installed
##Draw a wiring diagram of custom components
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || Tom & James || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || Tom and James || 5/28/17 || We've got some stray AC current in the case.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-30T23:47:36Z

James: updated power level control point labels following Sunday soldering session

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#
#
#Laser power supply power level control potentiometer GND
#Auto power control voltage divided between +V and GND - connects to auto-hand control panel switch and to PWM-DC converter circuit output
#Laser power supply power level control potentiometer +V

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || Tom & James || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || Tom and James || 5/28/17 || We've got some stray AC current in the case.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-30T22:40:46Z

James: listed installed safeties: cutting chamber, control chamber, water level

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''Only some of these safeties are installed presently.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom. For troubleshooting purposes, there is a safety override switch on the control panel (middle of three).
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level - Installed
#Flow
#Temp
===Doors===
#Cutting Chamber - Installed
#Control Chamber - Installed
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#
#
#Auto-hand power control switch - common
#Auto-hand power control switch - n.o.
#Auto-hand power control switch - n.c.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##in the config you specify this with laser_module_ttl_pin
##determine relay requirements
##purchase and receive relay
##install firing relay
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above
##We're gonna use Laserweb I think so setup a RasPi or something as a Laserweb server.

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || Tom & James || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on. PWM out can be set using laser_module_pwm_pin in smoothieboard config.
|-
| Setup the auto-man power level control switch. General stuff. || Tom and James || 5/28/17 || We've got some stray AC current in the case.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-15T02:17:47Z

James: added float switch and auto-hand switch

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber door safety switch - common
#Cutting chamber door safety switch - n.o.
#Cutting chamber door safety switch - n.c.
#Control chamber door safety switch - common
#Control chamber door safety switch - n.o.
#Control chamber door safety switch - n.c.
#Cooling water level float safety switch - common
#Cooling water level float safety switch - n.o.
#Cooling water level float safety switch - n.c.
#
#
#
#
#
#
#
#
#
#Auto-hand power control switch - common
#Auto-hand power control switch - n.o.
#Auto-hand power control switch - n.c.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|-
| Install float switch. || James || 5/11/17 || Not seeming to function as of 5/14 - remains conductive even when open?
|-
| Successful CNC laser firing on circle laser test. || Tom & James || 5/14/17 || Some kind of beam splitting or 2-layer reflection is going on.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

File:Float-switch-base.stl

2017-05-10T05:12:21Z

James: James uploaded a new version of "File:Float-switch-base.stl": v5 update to adjust screw threads

Base of cooling water level float switch. Needs 1/4-20 all thread legs, or I could redesign it to use two packs of chopsticks. Version 2.
[[Category: CheapChineseLaser]]

Float switch

2017-05-10T05:10:14Z

James: v5 update to adjust foot threads, etc.

This is the source code for the float switch 3d printed parts for the water level detector for the [[Cheap Chinese Laser]].
It is made in two parts: the head and the base.
You also need 4 pieces of 1/4-20 all thread to connect the two of them and 8 nuts.
The base is internally threaded. The head needs nuts top and bottom. Washers would be good too.

[[File:Float-switch-head.stl]] rendered on 5/1/2017

[[File:Float-switch-base.stl]] rendered on 5/7/2017

<pre>
/*
low water level detector
safety interlock for cheap Chinese laser at Hac DC
This water level detector is a two piece assembly connected by threaded rod. This model uses 1/4-20 rod. The lower foot has a 40mm home in the bottom to insert a pingpong ball as the float.
James Sullivan
5-8-17
Mk 5 - removed tolerance variable and adjusted threads, ppbd, and head threaded rod holes diameters
OpenSCAD version 2015.03-1
*/
ppbd=41; //ping pong ball diameter, includes 1mm tolerance
ppbw=2.7; //ping pong ball weight in grams
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
wlh=200; //water level height
sbw=6; //switch body width
nfw=4; //nut face width, switch mounting nuts
nt=1; //nut thickness, switch mounting nuts
thick=5; //thickness
eps=0.1; //epsilon
br=50; //base radius
rod=25.4/4; //rod outer diameter
tpi=20; //threads per inch
td=13.74/tpi; //thread depth
fph=25.4*5/tpi;//foot pillar height
bfw=ppbd+2*thick; //base flange width
$fn=48;
function mod(num,den) = num - floor(num/den)*den;
//dimensions taken from Front Door Switch Holder
wr=4; //wrench size for nuts width across flats
nh=1; //nut height, depth of nut sockets

//head
module head() {
color("cyan") difference(){
union(){
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+td,0,0]) cylinder(d=rod+thick*2,h=thick); //leg cylinders
}
cylinder(h=thick,r=ppbd/2+rod/2+td-thick/2);
}
translate([0,0,-thick/2]) cylinder(h=thick*2,r=ppbd/2+rod/2-3*thick/2); //center bore to reduce material amount and print time
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+td,0,-thick/2]) cylinder(d=rod*1.1,h=thick*2); //leg holes for threaded rods
}
}
translate([sbw/2,(ppbd+rod-2*thick)/(-2),0]) cube([thick,ppbd+rod-2*thick,thick]); //support for switch mounting block
translate([sbw/2,shp/2,thick]) difference(){ //switch mounting block, aligned with z-plane and x-plane, centered on y-plane
translate([0,-shp/2-nfw,0]) color("green") cube([thick,shp+2*nfw,2*nfw]);
for (y=[-shp/2,shp/2]) {
translate([thick/2,y,nfw]) rotate([0,90,0]) cylinder(d=shd,h=thick*2,center=true); //screw holes
translate([sbw-nh,y,nfw]) union(){ //nut sockets
for (ang=[0,120,240]) rotate([ang,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
translate([sbw/2+thick,bfw/2-nfw-shp,nfw]) union(){ //center nut socket
cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([120,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([240,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
}

module socket(nd,tpi,tl,thick) {
//nd = nominal diameter
//tpi = threads per inch
//tl = thread length
ror=nd/2; //rod outer radius
pitch=25.4/tpi; //thread pitch in mm
td=13.74/tpi; //thread depth in mm
rir=ror-td; //rod inner radius
sor=ror+thick; //socket outer radius
vert= [for (ang=[0:360/$fn:720]) ang<=90 ? [cos(ang),sin(ang)]*rir :
ang<202.5 ? [cos(ang),sin(ang)]*(rir+td*(ang-90)/112.5) :
ang<=247.5 ? [cos(ang),sin(ang)]*ror :
ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/112.5) :
[cos(ang),sin(ang)]*sor];
path1=[for(p=[0:$fn]) p<$fn ? p : 0 ];
path2=[for(p=[$fn:2*$fn]) p<2*$fn ? p : $fn ];
color("green") difference(){
linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
polygon(points=vert,paths=[path1,path2]);
}
translate([0,0,tl-ror*tan(30)]) cylinder(r2=ror,r1=0,h=ror*tan(30)); //inlet chamfer
}
}

//foot
module foot(){
difference(){
union(){
translate([0,0,thick/2]) cube([ppbd+2*thick,ppbd+2*thick,thick],center=true);
for (angle=[45:90:315]){
rotate([0,0,angle]){
translate([ppbd/2+rod/2+13.74/tpi,0,thick]) socket(rod*1.1,tpi,fph,thick); //pillar
translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
translate([br-thick,0,0]) cylinder(r=thick,h=thick); //foot
} //end rotate
} //end for
} //end union
translate([0,0,-eps/2]) cylinder(d=ppbd,h=fph+eps+thick); //ping pong ball entry
} //end difference
} //end foot module

//head();
foot();
</pre>

[[Category: CheapChineseLaser]]

Cheap Chinese Laser

2017-05-08T03:47:28Z

James: noted low 5V circuit current capacity on 5/7

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber safety switch - common
#Cutting chamber safety switch - n.o.
#Cutting chamber safety switch - n.c.
#Control chamber safety switch - common
#Control chamber safety switch - n.o.
#Control chamber safety switch - n.c.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working. Laser power supply 5V circuit for safety switches doesn't have enough current to illuminate the trouble lamps on front panel.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-08T03:44:33Z

James: added 5/7

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber safety switch - common
#Cutting chamber safety switch - n.o.
#Cutting chamber safety switch - n.c.
#Control chamber safety switch - common
#Control chamber safety switch - n.o.
#Control chamber safety switch - n.c.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch and water level float switch head and base. Remodeled exhaust header. || James || 5/6/17 || Holders fit great. Base, not so much.
|-
| Reprinted water level float switch base. Investigated PWM output from Smoothieboard. || Tom & James || 5/7/17 || Pin 4.2 and GND work for PWM signal. PWM to DC breadboard isn't working.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

File:Float-switch-base.stl

2017-05-08T03:38:59Z

James: James uploaded a new version of "File:Float-switch-base.stl": Version 3. Shortened thread sockets to 5 threads. Added inlet chamfer to threads. Added 0.5mm diameter tolerance to threads.

Base of cooling water level float switch. Needs 1/4-20 all thread legs, or I could redesign it to use two packs of chopsticks. Version 2.
[[Category: CheapChineseLaser]]

Float switch

2017-05-08T03:35:28Z

James: v3 updated foot section to increase tolerance and socket to add inlet chamfer

This is the source code for the float switch 3d printed parts for the water level detector for the [[Cheap Chinese Laser]].
It is made in two parts: the head and the base.
You also need 4 pieces of 1/4-20 all thread to connect the two of them and 8 nuts.
The base is internally threaded. The head needs nuts top and bottom. Washers would be good too.

[[File:Float-switch-head.stl]] rendered on 5/1/2017

[[File:Float-switch-base.stl]] rendered on 5/7/2017

<pre>
/*
low water level detector
safety interlock for cheap Chinese laser at Hac DC
This water level detector is a two piece assembly connected by threaded rod. This model uses 1/4-20 rod. The lower foot has a 40mm home in the bottom to insert a pingpong ball as the float.
James Sullivan
4-30-17
Mk 2 - calculated threads
OpenSCAD version 2015.03-1
*/
ppbd=40; //ping pong ball diameter
ppbw=2.7; //ping pong ball weight in grams
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
wlh=200; //water level height
sbw=6; //switch body width
nfw=4; //nut face width, switch mounting nuts
nt=1; //nut thickness, switch mounting nuts
thick=5; //thickness
eps=0.1; //epsilon
tol=0.5; //tolerance
br=50; //base radius
rod=25.4/4; //rod outer diameter
tpi=20; //threads per inch
fph=25.4*5/tpi;//foot pillar height
bfw=ppbd+2*thick; //base flange width
$fn=40;
function mod(num,den) = num - floor(num/den)*den;
//dimensions taken from Front Door Switch Holder
wr=4; //wrench size for nuts width across flats
nh=1; //nut height, depth of nut sockets

//head
module head() {
difference(){
union(){
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,0]) cylinder(d=rod+thick*2,h=thick); //leg cylinders
}
cylinder(h=thick,r=ppbd/2+rod/2+tol-thick/2);
}
translate([0,0,-thick/2]) cylinder(h=thick*2,r=ppbd/2+rod/2+tol-3*thick/2);
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,-thick/2]) cylinder(d=rod,h=fph); //leg holes
}
}
translate([sbw/2,(ppbd+rod+tol-2*thick)/(-2),0]) cube([thick,ppbd+rod+tol-2*thick,thick]);
translate([sbw/2,shp/2,thick]) difference(){ //switch mounting block, aligned with z-plane and x-plane, centered on y-plane
translate([0,-shp/2-nfw,0]) color("green") cube([thick,shp+2*nfw,2*nfw]);
for (y=[-shp/2,shp/2]) {
translate([thick/2,y,nfw]) rotate([0,90,0]) cylinder(d=shd,h=thick*2,center=true); //screw holes
translate([sbw-nh,y,nfw]) union(){ //nut sockets
for (ang=[0,120,240]) rotate([ang,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
translate([sbw/2+thick,bfw/2-nfw-shp,nfw]) union(){ //center nut socket
cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([120,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([240,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
}

module socket(nd,tpi,tl,thick) {
//nd = nominal diameter
//tpi = threads per inch
//tl = thread length
ror=nd/2; //rod outer radius
pitch=25.4/tpi; //thread pitch in mm
td=pitch*3/4; //thread depth in mm
rir=ror-td; //rod inner radius
sor=ror+thick; //socket outer radius
vert= [for (ang=[0:360/$fn:720]) ang<=45 ? [cos(ang),sin(ang)]*rir : ang<180 ? [cos(ang),sin(ang)]*(rir+td*(ang-45)/135) : ang<=225 ? [cos(ang),sin(ang)]*ror : ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/135) : [cos(ang),sin(ang)]*sor];
path1=[for(p=[0:$fn]) mod(p,$fn) ];
path2=[for(p=[0:$fn]) mod(p,$fn)+$fn ];
difference(){
linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
polygon(points=vert,paths=[path1,path2]);
}
translate([0,0,tl-ror*tan(30)]) cylinder(r2=ror,r1=0,h=ror*tan(30)); //inlet chamfer
}
}

//foot
module foot(){
difference(){
union(){
translate([0,0,thick/2]) cube([ppbd+2*thick,ppbd+2*thick,thick],center=true);
for (angle=[45:90:315]){
rotate([0,0,angle]){
translate([ppbd/2+rod/2+tol,0,thick]) socket(rod,tpi,fph,thick); //pillar
translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
translate([br-thick,0,0]) cylinder(r=thick,h=thick); //foot
} //end rotate
} //end for
} //end union
translate([0,0,-eps/2]) cylinder(d=ppbd+tol,h=fph+eps+thick); //ping pong ball entry
} //end difference
} //end foot module

foot();
//head();
</pre>

[[Category: CheapChineseLaser]]

File:Airflow-switch.stl

2017-05-07T06:11:31Z

James: added v2 problems

Version 2 airflow switch holder for [[Cheap Chinese Laser]].
This model was created from the source code here [[Air flow switch holder]].
There are still problems with this design. The flap doesn't clear the switch, the flap probably doesn't make enough torque to switch the switch, the axle holes are too small, and the switch mounting screws will run into the attached header.
[[Category: CheapChineseLaser]]

File:Airflow-switch.stl

2017-05-07T04:22:55Z

James: James uploaded a new version of "File:Airflow-switch.stl": adjusted filler block between switch and wafer to unblock hinge pin hole

Version 2 airflow switch holder for [[Cheap Chinese Laser]].
This model was created from the source code here [[Air flow switch holder]].
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-07T04:22:02Z

James: adjusted height and position of filler block between switch holder and wafer flanges to unblock hinge pin hole

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the header doesn't quite match, even though the nozzle was reverse engineered from it.

This was printed on 5/1 and it has some issues.
#The arms which hold the switch body interfere with the flap plate.
#The flap plate axis of rotation could be lowered to improve the balance.
#The thickness of the wafer can be increased to reduce the warpage of the piece.
Model was redesigned on 5/5:
#Switch holder moved to side from top center
#Flap axis of rotation lowered
#Up arrow added
#Thickness increased from 3 to 5 mm
#Wire holes relocated 180°
You can find the stl file here [[File:Airflow-switch.stl]]
<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis.
When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of
the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
5-5-17, v2
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge
*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
thick=5; //thickness of flange - originally 3, but warped when removing from printer bed
flap=3; //thickness of flap - originally 3, but warped when removing from printer bed
hph=bhd*2; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable. - originally 10
sfw=fid-thick*2; //switch flap width - originally sqrt(fid*fid-4*hph*hph)
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=12; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
$fn=80;

difference(){ //wafer body
union(){
cylinder(d=fod,h=thick);
for(ang=[0,90]){
rotate([0,0,ang]) hull(){ //lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([sfw/2+thick/2,0,thick]) rotate([-90,0,0]) cylinder(d1=shd*1.6,d2=0,h=shd*2);//up direction arrow head
translate([sfw/2+thick/2,0,thick]) rotate([90,0,0]) cylinder(d=shd*0.8,h=shd*2); //up direction arrow shaft
}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[235:5:245]){ //wire holes through flange
translate([0,0,thick-flap/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
} //end of wafer body
translate([-thick/2-sfw/2,0,flap/2+srh]){ //switch holder
difference(){
union(){
cube([thick,shp+3*shd,3*shd],center=true);//mount flange
color("blue") translate([0,0,-srh/2-flap/4+thick/2-3*shd/4]) cube([thick,shp+3*shd,srh+flap/2-thick-3*shd/2],center=true); //support for mount flange
translate([-thick/2,0,-shd*2]) cylinder(d2=shd*1.6,d1=0,h=shd*2.0);//flow direction arrow head
translate([-thick/2,0,-shd/2]) cylinder(d=shd*0.8,h=shd*2.0); //flow direction arrow shaft
}
for (dy=[-shp/2,shp/2]) {
translate([0,dy,0]) rotate([0,90,0]) cylinder(d=shd,h=2*thick,center=true); //bolt holes
for (angle=[0:120:240]){
translate([-thick/2,dy,0]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //nut sockets
}
}
}
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=flap); //circular top and bottom
cube([sfw-0.5,fod,flap*2],true); //vertical left and right
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Cheap Chinese Laser

2017-05-07T04:19:43Z

James: added terminal number listing

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

Terminal Block Connections
#Cutting chamber safety switch - common
#Cutting chamber safety switch - n.o.
#Cutting chamber safety switch - n.c.
#Control chamber safety switch - common
#Control chamber safety switch - n.o.
#Control chamber safety switch - n.c.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch. Remodeled exhaust header. || James || 5/6/17 || Holders fit great.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-07T02:09:56Z

James: 5/6 update

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|-
| Printed and installed new terminal block holders (v2). Printed new air flow switch. Remodeled exhaust header. || James || 5/6/17 || Holders fit great.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

File:Airflow-switch.stl

2017-05-07T02:01:31Z

James: James uploaded a new version of "File:Airflow-switch.stl": changed height of switch screw holes and enlarged flow direction arrow

Version 2 airflow switch holder for [[Cheap Chinese Laser]].
This model was created from the source code here [[Air flow switch holder]].
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-07T01:51:52Z

James: changed value of switch roller height (srh) and elevation of switch holder

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the header doesn't quite match, even though the nozzle was reverse engineered from it.

This was printed on 5/1 and it has some issues.
#The arms which hold the switch body interfere with the flap plate.
#The flap plate axis of rotation could be lowered to improve the balance.
#The thickness of the wafer can be increased to reduce the warpage of the piece.
Model was redesigned on 5/5:
#Switch holder moved to side from top center
#Flap axis of rotation lowered
#Up arrow added
#Thickness increased from 3 to 5 mm
#Wire holes relocated 180°
You can find the stl file here [[File:Airflow-switch.stl]]
<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis.
When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of
the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
5-5-17, v2
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge
*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
thick=5; //thickness of flange - originally 3, but warped when removing from printer bed
flap=3; //thickness of flap - originally 3, but warped when removing from printer bed
hph=bhd*2; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable. - originally 10
sfw=fid-thick*2; //switch flap width - originally sqrt(fid*fid-4*hph*hph)
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=12; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
$fn=80;

difference(){ //wafer body
union(){
cylinder(d=fod,h=thick);
for(ang=[0,90]){
rotate([0,0,ang]) hull(){ //lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([sfw/2+thick/2,0,thick]) rotate([-90,0,0]) cylinder(d1=shd*1.6,d2=0,h=shd*2);//up direction arrow head
translate([sfw/2+thick/2,0,thick]) rotate([90,0,0]) cylinder(d=shd*0.8,h=shd*2); //up direction arrow shaft

}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[235:5:245]){ //wire holes through flange
translate([0,0,thick-flap/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
} //end of wafer body
translate([-thick/2-sfw/2,0,flap/2+srh]){ //switch holder
difference(){
union(){
cube([thick,shp+3*shd,3*shd],center=true);//mount flange
color("blue") translate([0,0,-srh/2-shd/2]) cube([thick,shp+3*shd,srh],center=true); //support for mount flange
translate([-thick/2,0,-shd*1.5]) cylinder(d2=shd*1.2,d1=0,h=shd*1.5);//flow direction arrow head
translate([-thick/2,0,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
}
for (dy=[-shp/2,shp/2]) {
translate([0,dy,0]) rotate([0,90,0]) cylinder(d=shd,h=2*thick,center=true); //bolt holes
for (angle=[0:120:240]){
translate([-thick/2,dy,0]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //nut sockets
}
}
}
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=flap); //circular top and bottom
cube([sfw-0.5,fod,flap*2],true); //vertical left and right
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-05T23:28:56Z

James: added newlines to initial comment to prevent text running off the edge of the screen

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the header doesn't quite match, even though the nozzle was reverse engineered from it.

This was printed on 5/1 and it has some issues.
#The arms which hold the switch body interfere with the flap plate.
#The flap plate axis of rotation could be lowered to improve the balance.
#The thickness of the wafer can be increased to reduce the warpage of the piece.
Model was redesigned on 5/5:
#Switch holder moved to side from top center
#Flap axis of rotation lowered
#Up arrow added
#Thickness increased from 3 to 5 mm
#Wire holes relocated 180°
You can find the stl file here [[File:Airflow-switch.stl]]
<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis.
When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of
the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
5-5-17, v2
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge
*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
thick=5; //thickness of flange - originally 3, but warped when removing from printer bed
flap=3; //thickness of flap - originally 3, but warped when removing from printer bed
hph=bhd*2; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable. - originally 10
sfw=fid-thick*2; //switch flap width - originally sqrt(fid*fid-4*hph*hph)
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=8; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
$fn=80;

difference(){ //wafer body
union(){
cylinder(d=fod,h=thick);
for(ang=[0,90]){
rotate([0,0,ang]) hull(){ //lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([sfw/2+thick/2,0,thick]) rotate([-90,0,0]) cylinder(d1=shd*1.6,d2=0,h=shd*2);//up direction arrow head
translate([sfw/2+thick/2,0,thick]) rotate([90,0,0]) cylinder(d=shd*0.8,h=shd*2); //up direction arrow shaft

}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[235:5:245]){ //wire holes through flange
translate([0,0,thick-flap/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
} //end of wafer body
translate([-thick/2-sfw/2,0,thick+srh]){ //switch holder
difference(){
union(){
cube([thick,shp+3*shd,3*shd],center=true);//mount flange
color("blue") translate([0,0,-srh/2-shd/2]) cube([thick,shp+3*shd,srh],center=true); //support for mount flange
translate([-thick/2,0,-shd*1.5]) cylinder(d2=shd*1.2,d1=0,h=shd*1.5);//flow direction arrow head
translate([-thick/2,0,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
}
for (dy=[-shp/2,shp/2]) {
translate([0,dy,0]) rotate([0,90,0]) cylinder(d=shd,h=2*thick,center=true); //bolt holes
for (angle=[0:120:240]){
translate([-thick/2,dy,0]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //nut sockets
}
}
}
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=flap); //circular top and bottom
cube([sfw-0.5,fod,flap*2],true); //vertical left and right
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-05T23:27:45Z

James: added link to stl file

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the header doesn't quite match, even though the nozzle was reverse engineered from it.

This was printed on 5/1 and it has some issues.
#The arms which hold the switch body interfere with the flap plate.
#The flap plate axis of rotation could be lowered to improve the balance.
#The thickness of the wafer can be increased to reduce the warpage of the piece.
Model was redesigned on 5/5:
#Switch holder moved to side from top center
#Flap axis of rotation lowered
#Up arrow added
#Thickness increased from 3 to 5 mm
#Wire holes relocated 180°
You can find the stl file here [[File:Airflow-switch.stl]]
<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis. When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
5-5-17, v2
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge
*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
thick=5; //thickness of flange - originally 3, but warped when removing from printer bed
flap=3; //thickness of flap - originally 3, but warped when removing from printer bed
hph=bhd*2; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable. - originally 10
sfw=fid-thick*2; //switch flap width - originally sqrt(fid*fid-4*hph*hph)
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=8; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
$fn=80;

difference(){ //wafer body
union(){
cylinder(d=fod,h=thick);
for(ang=[0,90]){
rotate([0,0,ang]) hull(){ //lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([sfw/2+thick/2,0,thick]) rotate([-90,0,0]) cylinder(d1=shd*1.6,d2=0,h=shd*2);//up direction arrow head
translate([sfw/2+thick/2,0,thick]) rotate([90,0,0]) cylinder(d=shd*0.8,h=shd*2); //up direction arrow shaft

}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[235:5:245]){ //wire holes through flange
translate([0,0,thick-flap/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
} //end of wafer body
translate([-thick/2-sfw/2,0,thick+srh]){ //switch holder
difference(){
union(){
cube([thick,shp+3*shd,3*shd],center=true);//mount flange
color("blue") translate([0,0,-srh/2-shd/2]) cube([thick,shp+3*shd,srh],center=true); //support for mount flange
translate([-thick/2,0,-shd*1.5]) cylinder(d2=shd*1.2,d1=0,h=shd*1.5);//flow direction arrow head
translate([-thick/2,0,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
}
for (dy=[-shp/2,shp/2]) {
translate([0,dy,0]) rotate([0,90,0]) cylinder(d=shd,h=2*thick,center=true); //bolt holes
for (angle=[0:120:240]){
translate([-thick/2,dy,0]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //nut sockets
}
}
}
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=flap); //circular top and bottom
cube([sfw-0.5,fod,flap*2],true); //vertical left and right
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}</nowiki>
</pre>
[[Category: CheapChineseLaser]]

File:Airflow-switch.stl

2017-05-05T23:26:04Z

James: Version 2 airflow switch holder for Cheap Chinese Laser. This model was created from the source code here Air flow switch holder. Category: CheapChineseLaser

Version 2 airflow switch holder for [[Cheap Chinese Laser]].
This model was created from the source code here [[Air flow switch holder]].
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-05T23:23:17Z

James: version 2

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the header doesn't quite match, even though the nozzle was reverse engineered from it.

This was printed on 5/1 and it has some issues.
#The arms which hold the switch body interfere with the flap plate.
#The flap plate axis of rotation could be lowered to improve the balance.
#The thickness of the wafer can be increased to reduce the warpage of the piece.
Model was redesigned on 5/5:
#Switch holder moved to side from top center
#Flap axis of rotation lowered
#Up arrow added
#Thickness increased from 3 to 5 mm
#Wire holes relocated 180°

<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis. When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
5-5-17, v2
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge
*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
thick=5; //thickness of flange - originally 3, but warped when removing from printer bed
flap=3; //thickness of flap - originally 3, but warped when removing from printer bed
hph=bhd*2; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable. - originally 10
sfw=fid-thick*2; //switch flap width - originally sqrt(fid*fid-4*hph*hph)
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=8; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
$fn=80;

difference(){ //wafer body
union(){
cylinder(d=fod,h=thick);
for(ang=[0,90]){
rotate([0,0,ang]) hull(){ //lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([sfw/2+thick/2,0,thick]) rotate([-90,0,0]) cylinder(d1=shd*1.6,d2=0,h=shd*2);//up direction arrow head
translate([sfw/2+thick/2,0,thick]) rotate([90,0,0]) cylinder(d=shd*0.8,h=shd*2); //up direction arrow shaft

}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[235:5:245]){ //wire holes through flange
translate([0,0,thick-flap/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
} //end of wafer body
translate([-thick/2-sfw/2,0,thick+srh]){ //switch holder
difference(){
union(){
cube([thick,shp+3*shd,3*shd],center=true);//mount flange
color("blue") translate([0,0,-srh/2-shd/2]) cube([thick,shp+3*shd,srh],center=true); //support for mount flange
translate([-thick/2,0,-shd*1.5]) cylinder(d2=shd*1.2,d1=0,h=shd*1.5);//flow direction arrow head
translate([-thick/2,0,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
}
for (dy=[-shp/2,shp/2]) {
translate([0,dy,0]) rotate([0,90,0]) cylinder(d=shd,h=2*thick,center=true); //bolt holes
for (angle=[0:120:240]){
translate([-thick/2,dy,0]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //nut sockets
}
}
}
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=flap); //circular top and bottom
cube([sfw-0.5,fod,flap*2],true); //vertical left and right
}
translate([0,hph,flap/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Cheap Chinese Laser

2017-05-05T21:10:54Z

James: 4/5 & 5/5 added

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|-
| Installed terminal block with manually modified v1 terminal block holder parts. Wired up cutting chamber and control chamber door safety switches. Connected laser power supply wiring to new control panel switches. || James || 5/4/17 || Need to adjust terminal block holder dimensions and reprint.
|-
| Uploaded v2 source code and stl for terminal block holder. || James || 5/5/17 || Need to print float switch parts and terminal block holders.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-05T21:04:36Z

James: Added terminal block holder link to custom parts section

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

[[Terminal block holder]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

File:Tbh.stl

2017-05-05T21:00:36Z

James: James uploaded a new version of "File:Tbh.stl": v2 upload with adjusted dimensions of the individual parts and relocated mirror image to reduce travel time of extruder when going from left hand to right hand parts during printing.

Terminal block holder stl file.
[[Category: CheapChineseLaser]]

Terminal block holder

2017-05-05T20:57:34Z

James: updated dimensions to make v2 after trial fit of v1 didn't work so well.

[[File:Tbh.stl]]

<pre>
<nowiki>
//Terminal Block Holder v2 - reduced height from 15 to 10 and raised screw hole 2mm by reducing end width (EW) from 12 to 8.
//James Sullivan
//5/1/17
//OpenSCAD version 2015.03-1
//HacDC, cheap Chinese laser, K40, 40 watt
//These parts hold a terminal block for landing of the wires going to the safety interlock switches. It is designed to use self threading
screws without nuts. Handedness is based upon which end of the terminal strip the mount sets on when looking at the terminal strip.
The right piece goes toward the back of the machine, and the left piece goes toward the front. The first version was too tall to slide
on the front of the chassis and too long to fit on the back, so both dimensions are reduced here in version 2.
thick=5; //thickness of part
metal=1; //metal thickness of the chassis sheet metal
slot=16; //width of slot in mount, width of flange on machine, full width outside to outside!
height = 10; //z distance of mount, extrusion height, installed length
tw=slot+2*thick; //total width
$fn=40;
bhd=4.0; //bolt hole diameter
et=4.0; //end thickness between bolt hole perimeter and square end
ew=8.0; //end width: height of mounting boss
foo=6.7; //width of cylinders
foo2=8.7; //thickness of terminal strip in axial direction of mounting screws
rd=2.8; //root diameter of mounting screws
module right(){ difference(){
union(){
cube([tw,thick,height]); //top horizontal
translate([thick+metal,-thick-metal,0]) cube([slot+thick-metal,thick,height]); //lower horizontal
translate([0,-metal-thick*1.5,0]) cube([thick,metal+thick*2.5,height]); //left vertical
translate([thick+metal,-1.5*thick-metal,0]) cube([thick,thick*1.5,height]); //center vertical
translate([slot+thick,-metal-thick,0]) cube([thick,metal+thick*2,height]); //right vertical
translate([thick*2,-ew-metal,0]) cube([slot-thick,ew,height+bhd+2*et]);
}
translate([0,-ew/2-metal,height+et+bhd/2]) rotate([0,90,0]) cylinder(d=rd,h=tw);
}}

right();
translate([0,-ew*2-metal*3,0]) mirror([0,1,0]) right();
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-03T04:47:54Z

James: added points for improvement

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the nacelle doesn't quite match, even though the nozzle was reverse engineered from it.

This was printed on 5/1 and it has some issues.
#The arms which hold the switch body interfere with the flap plate.
#The flap plate axis of rotation could be lowered to improve the balance.
#The thickness of the wafer can be increased to reduce the warpage of the piece.

<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis. When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
4-20-17
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge

*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
hph=10; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable.
sfw=sqrt(fid*fid-4*hph*hph); //switch flap width
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=8; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
thick=3; //thickness of flange
$fn=80;

difference(){
union(){
cylinder(d=fod,h=thick); //wafer body
hull(){ //horizontal lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
rotate([0,0,90]) hull(){ //vertical lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[55:5:65]){ //wire holes through flange
translate([0,0,thick/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,thick/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
}
translate([0,fid/2-shp-3*shd,0]){ //switch holder
difference(){
union(){
translate([sbw/2,0,0]) cube([thick,shp+3*shd,3*shd]); //left mount flange
translate([-sbw/2-thick,0,0]) cube([thick,shp+3*shd,3*shd]);//right mount flange
}
translate([-sbw/2-3/2*thick,3/2*shd,3/2*shd]) rotate([0,90,0]) cylinder(d=shd,h=sbw+3*thick); //lower bolt hole
translate([-sbw/2-3/2*thick,shp+3/2*shd,3/2*shd]) rotate([0,90,0]) cylinder(d=shd,h=sbw+3*thick);//upper bolt hole
for (angle=[0:120:240]){
translate([-sbw/2-thick,3/2*shd,3/2*shd]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //lower nut socket
translate([-sbw/2-thick,shp+3/2*shd,3/2*shd]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //upper nut socket
}
}
translate([sbw/2+thick,shp/2+shd*1.5,shd*1.5]) cylinder(d1=shd*1.2,d2=0,h=shd*1.5); //flow direction arrow head
translate([sbw/2+thick,shp/2+shd*1.5,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
translate([-sbw/2-thick,shp/2+shd*1.5,shd*1.5]) cylinder(d1=shd*1.2,d2=0,h=shd*1.5);//flow direction arrow head
translate([-sbw/2-thick,shp/2+shd*1.5,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=thick); //circular top and bottom
cube([sfw-0.5,fod,thick*2],true); //vertical left and right
}
translate([0,hph,thick/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Cheap Chinese Laser

2017-05-02T03:50:17Z

James: updated 5/1/17 entry

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for water level float switch and for terminal block holders. Installed v5 of door switch holder and soldered wires to switches. || James || 5/1/17 || Still need to print float switch parts and terminal block holders. New parts fit well. A very productive day overall.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Cheap Chinese Laser

2017-05-02T03:47:29Z

James: clean up of interlock tasks

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply [https://www.amazon.com/uxcell-Terminals-Pitch-Mount-Terminal/dp/B00E6Q4FE6/ref=sr_1_9?ie=UTF8&qid=1493691567&sr=8-9&keywords=pluggable+terminal+block+connector]

==To-Do Tasks==
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Door switches
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for float switch || James || 5/1/17 || Still need to print them.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Terminal block holder

2017-05-02T03:43:22Z

James: added link to stl file

[[File:Tbh.stl]]

<pre>
<nowiki>
//Terminal Block Holder v1
//James Sullivan
//5/1/17
//OpenSCAD version 2015.03-1
//HacDC, cheap Chinese laser, K40, 40 watt
//These parts hold a terminal block for landing of the wires going to the safety interlock switches. It is designed to use self threading screws without nuts. Handedness is based upon which end of the terminal strip the mount sets on when looking at the terminal strip. The right piece goes toward the back of the machine and is installed first. The left piece goes toward the front of the machine and is installed second.
thick=5; //thickness of part
metal=1; //metal thickness of the chassis sheet metal
slot=16; //width of slot in mount, width of flange on machine, full width outside to outside!
height = 15; //z distance of mount, extrusion height, installed length
tw=slot+2*thick; //total width
$fn=40;
bhd=4.0; //bolt hole diameter
et=4.0; //end thickness between bolt hold perimeter and square end
ew=12.0; //end width
foo=6.7; //width of cylinders
foo2=8.7; //thickness of terminal strip in axial direction of mounting screws
rd=2.8; //root diameter of mounting screws
module right(){ difference(){
union(){
cube([tw,thick,height]); //top horizontal
translate([thick+metal,-thick-metal,0]) cube([slot+thick-metal,thick,height]); //lower horizontal
translate([0,-metal-thick*1.5,0]) cube([thick,metal+thick*2.5,height]); //left vertical
translate([thick+metal,-1.5*thick-metal,0]) cube([thick,thick*1.5,height]); //center vertical
translate([slot+thick,-metal-thick,0]) cube([thick,metal+thick*2,height]); //right vertical
translate([thick*2,-ew-metal,0]) cube([slot-thick,ew,height+bhd+2*et]);
}
translate([0,-ew/2-metal,height+et+bhd/2]) rotate([0,90,0]) cylinder(d=rd,h=tw);
}}

right();
translate([0,20,0]) mirror([0,1,0]) right();
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

File:Tbh.stl

2017-05-02T03:42:20Z

James: Terminal block holder stl file. Category: CheapChineseLaser

Terminal block holder stl file.
[[Category: CheapChineseLaser]]

Terminal block holder

2017-05-02T03:36:03Z

James: page created

<pre>
<nowiki>
//Front Door Switch Holder v1
//James Sullivan
//5/1/17
//OpenSCAD version 2015.03-1
//HacDC, cheap Chinese laser, K40, 40 watt
//These parts hold a terminal block for landing of the wires going to the safety interlock switches. It is designed to use self threading screws without nuts. Handedness is based upon which end of the terminal strip the mount sets on when looking at the terminal strip. The right piece goes toward the back of the machine and is installed first. The left piece goes toward the front of the machine and is installed second.
thick=5; //thickness of part
metal=1; //metal thickness of the chassis sheet metal
slot=16; //width of slot in mount, width of flange on machine, full width outside to outside!
height = 15; //z distance of mount, extrusion height, installed length
tw=slot+2*thick; //total width
$fn=40;
bhd=4.0; //bolt hole diameter
et=4.0; //end thickness between bolt hold perimeter and square end
ew=12.0; //end width
foo=6.7; //width of cylinders
foo2=8.7; //thickness of terminal strip in axial direction of mounting screws
rd=2.8; //root diameter of mounting screws
module right(){ difference(){
union(){
cube([tw,thick,height]); //top horizontal
translate([thick+metal,-thick-metal,0]) cube([slot+thick-metal,thick,height]); //lower horizontal
translate([0,-metal-thick*1.5,0]) cube([thick,metal+thick*2.5,height]); //left vertical
translate([thick+metal,-1.5*thick-metal,0]) cube([thick,thick*1.5,height]); //center vertical
translate([slot+thick,-metal-thick,0]) cube([thick,metal+thick*2,height]); //right vertical
translate([thick*2,-ew-metal,0]) cube([slot-thick,ew,height+bhd+2*et]);
}
translate([0,-ew/2-metal,height+et+bhd/2]) rotate([0,90,0]) cylinder(d=rd,h=tw);
}}

right();
translate([0,20,0]) mirror([0,1,0]) right();
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

Air flow switch holder

2017-05-02T00:02:27Z

James: added <pre> tags and category

This is the OpenSCAD code to create a wafer air flow sensor (and backflow preventer) to hold a microswitch to stop the laser from firing if the exhaust flow stops. Dimensions have been set to match the exhaust nozzle. The current version of the nacelle doesn't quite match, even though the nozzle was reverse engineered from it.

<pre>
<nowiki>
/*
exhaust airflow detector
safety interlock for cheap Chinese laser at Hac DC
This switch is a lug style wafer for insertion between the exhaust collector and the exhaust nozzle on the back of the laser chassis. When the exhaust fan is running and air is flowing the switch will operate to allow the laser to fire. This switch is upstream of the exhaust fan so air will leak into the exhaust stream, not exhaust leaking out into room air.
James Sullivan
4-20-17
OpenSCAD version 2015.03-1

--dimensions from mating exhaust nozzle--
nid=60; //nozzle inner diameter
nod=80; //nozzle outer diameter
mod=100; //maximum outer diameter
sh=30; //step height
sw=5; //step width
oah=50; //over-all height
tlw=3; //top ledge width
bcd=46.8*2; //bolt circle diameter
bhd=3.6; //bolt hole diameter
fw=12; //foot width
fh=15; //foot height
fod=108; //foot outside dimension, from outside edge to outside edge
fid=(nid+nod)/2;//foot inside dimension, from inside edge to inside edge

*/
fid=60; //flange inner diameter, same as nid
fod=80; //flange outer diameter, same as nod
bhd=3.6; //bolt hole diameter
bcd=93.6;//bolt circle diameter
hph=10; //hinge pin height above center line, i.e. butterfly offset. Reduce to make switch more sensitive. Increse to make switch more stable.
sfw=sqrt(fid*fid-4*hph*hph); //switch flap width
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
srh=8; //switch roller height, i.e. height above switch hole centerline where switching action occurs
sbw=6; //switch body width
nfw=5; //nut face width
nt=1; //nut thickness
thick=3; //thickness of flange
$fn=80;

difference(){
union(){
cylinder(d=fod,h=thick); //wafer body
hull(){ //horizontal lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
rotate([0,0,90]) hull(){ //vertical lugs
translate([bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
translate([-bcd/2,0,0]) cylinder(d=3*bhd, h=thick);
}
}
translate([0,0,-thick/2]) intersection(){ //bore
cylinder(d=fid, h=2*thick); //circular top and bottom
cube([sfw,fod,thick*4],true); //vertical left and right
}
for (angle=[0:90:270]){ //bolt holes in lugs
rotate([0,0,angle]) translate([bcd/2,0,-thick/2]) cylinder(d=bhd,h=thick*2);
}
for (angle=[55:5:65]){ //wire holes through flange
translate([0,0,thick/2]) rotate([0,90,angle]) cylinder(d=1,h=bcd/2);
}
translate([0,hph,thick/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axle hole
}
translate([0,fid/2-shp-3*shd,0]){ //switch holder
difference(){
union(){
translate([sbw/2,0,0]) cube([thick,shp+3*shd,3*shd]); //left mount flange
translate([-sbw/2-thick,0,0]) cube([thick,shp+3*shd,3*shd]);//right mount flange
}
translate([-sbw/2-3/2*thick,3/2*shd,3/2*shd]) rotate([0,90,0]) cylinder(d=shd,h=sbw+3*thick); //lower bolt hole
translate([-sbw/2-3/2*thick,shp+3/2*shd,3/2*shd]) rotate([0,90,0]) cylinder(d=shd,h=sbw+3*thick);//upper bolt hole
for (angle=[0:120:240]){
translate([-sbw/2-thick,3/2*shd,3/2*shd]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //lower nut socket
translate([-sbw/2-thick,shp+3/2*shd,3/2*shd]) rotate([angle,0,0]) cube([nt*2,nfw,nfw/sqrt(3)],center=true); //upper nut socket
}
}
translate([sbw/2+thick,shp/2+shd*1.5,shd*1.5]) cylinder(d1=shd*1.2,d2=0,h=shd*1.5); //flow direction arrow head
translate([sbw/2+thick,shp/2+shd*1.5,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
translate([-sbw/2-thick,shp/2+shd*1.5,shd*1.5]) cylinder(d1=shd*1.2,d2=0,h=shd*1.5);//flow direction arrow head
translate([-sbw/2-thick,shp/2+shd*1.5,0]) cylinder(d=shd*0.6,h=shd*1.5); //flow direction arrow shaft
}

translate([0,fid/2+bcd/2+bhd*2,0]) difference(){ //flap disk
intersection(){ //bore
cylinder(d=fid-0.5, h=thick); //circular top and bottom
cube([sfw-0.5,fod,thick*2],true); //vertical left and right
}
translate([0,hph,thick/2]) rotate([0,90,0]) cylinder(d=1,h=bcd+4*bhd,center=true); //hinge pin axis
}
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

CCL front panel

2017-05-01T22:54:40Z

James: added <pre> tag to maintain source code whitespace

<pre>
<nowiki>
<svg width="174mm" height="184mm" viewBox="-87 -92.0 174 184">

<symbol id="Fan" fill="gray" >
<circle r="7" cx="50" cy="50"/>
<g id="blade">
<rect x="48" y="32" width="4" height="16"/>
<circle r="6" cx="50" cy="35"/>
<circle r="9" cx="50" cy="9"/>
<path d="M50 9 h9 l-3 26 h-12 l -3 -26z"/>
</g>
<use xlink:href="#blade" transform="rotate(72,50,50)"/>
<use xlink:href="#blade" transform="rotate(144,50,50)"/>
<use xlink:href="#blade" transform="rotate(216,50,50)"/>
<use xlink:href="#blade" transform="rotate(288,50,50)"/>
</symbol>

<symbol id="Pump">
<g fill="gray">
<path d="M50 4 h7 a 2 2 0 0 1 2 2 v 2 a 2 2 0 0 1 -2 2 h -5 v 20 h 6 a 6 6 0 0 1 6 6 v 56 a 6 6 0 0 1 -6 6 h -16 a 6 6 0 0 1 -6 -6 v -56 a 6 6 0 0 1 6 -6 h 6 m 0 4 h -5 a 3 3 0 0 0 -3 3 v 54 a 3 3 0 0 0 3 3 h 14 a 3 3 0 0 0 3 -3 v -54 a 3 3 0 0 0 -3 -3 h -5 v 6 h 2 a 3 3 0 0 1 3 3 v 16 a 3 3 0 0 1 -3 3 h -8 a 3 3 0 0 1 -3 -3 v -16 a 3 3 0 0 1 3 -3 h 2 v -6 m 0 -4 v -20 h -5 a 2 2 0 0 1 -2 -2 v -2 a 2 2 0 0 1 2 -2 h 7 z"/>
<path d="M3 56 q7.5 6 15 0 t15 0 v8 q-7.5 -6 -15 0 t-15 0 z"/>
<path d="M3 70 q7.5 6 15 0 t15 0 v8 q-7.5 -6 -15 0 t-15 0 z"/>
<path d="M3 84 q7.5 6 15 0 t15 0 v8 q-7.5 -6 -15 0 t-15 0 z"/>
<path d="M67 56 q7.5 6 15 0 t15 0 v8 q-7.5 -6 -15 0 t-15 0 z"/>
<path d="M67 70 q7.5 6 15 0 t15 0 v8 q-7.5 -6 -15 0 t-15 0 z"/>
<path d="M67 84 q7.5 6 15 0 t15 0 v8 q-7.5 -6 -15 0 t-15 0 z"/>
</g>
</symbol>

<symbol id="Temp">
<circle cx="65" cy="15" r="2.5" stroke-width="2" stroke="gray" fill="white"/>
<circle cx="50" cy="40" r="12" fill="gray"/>
<rect x="42" y="0" width="16" height="45" fill="gray" rx="10" r="10"/>
<circle cx="50" cy="40" r="9" fill="white"/>
<rect x="45" y="3" width="10" height="42" fill="white" rx="7" r="7"/>
<circle cx="50" cy="40" r="5" fill="gray"/>
<rect x="48" y="6" width="4" height="39" fill="gray" rx="4" r="4"/>
<circle cx="50" cy="25" r="2" fill="gray"/>
<line x1="50" y1="40" x2="50" y2="25" stroke-width="5"/>
<path d="M 5 60 q 15 10 30 0 t 30 0 30 0 v 10 q -15 10 -30 0 t -30 0 -30 0 z" fill="gray"/>
<path d="M 5 80 q 15 10 30 0 t 30 0 30 0 v 10 q -15 10 -30 0 t -30 0 -30 0 z" fill="gray"/>
</symbol>
<symbol id="Level" fill="gray">
<path d="M 0 20 v 65 a 15 15 0 0 0 15 15 h 70 a 15 15 0 0 0 15 -15 v -65 h -8 v 62 a 10 10 0 0 1 -10 10 h -64 a 10 10 0 0 1 -10 -10 v -62 z"/>
<path d="M 12 75 q 9.5 10 19 0 t 19 0 19 0 19 0 v 10 q -9.5 -10 -19 0 t -19 0 -19 0 -19 0 z"/>
<path d="M45 10 h 10 v 39 l 12 -12 7 7 -24 24 -24 -24 7 -7 12 12 z"/>
</symbol>
<symbol id="Laser">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<g transform="scale(0.9,1) skewY(10)">
<line x1="10" y1="40" x2="82" y2="40" stroke-width="5" stroke="gray"/>
<circle cx="88" cy="40" r="4" fill="gray"/>
<g transform="translate(88,40)">
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(-45)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(0)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(45)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(90)"/>
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<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(225)"/>
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<g transform="scale(0.8,1) skewY(20)">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<circle cx="48" cy="48" r="4" fill="gray"/>
</g>
</symbol>
<symbol id="Control">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<g transform="translate(90,10) rotate(45)">
<path d="M 0 0 l -10 22 10 10 -10 25 10 10 0 20 10 -22 -10 -10 10 -25 -10 -10 0 -20 z" stroke="gray" fill="gray"/>
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<g transform="scale(0.8,1) skewY(20)">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<circle cx="48" cy="48" r="4" fill="gray"/>
</g>
</symbol>
<g>
<title>Control Panel</title>"
#background
<rect x="-87" y="-92.0" width="174" height="184" fill="black"/>
#mounting tabs
<rect x="57.0" y="-92.0" width="18" height="184" rx="9.0" ry="9.0" fill="gray"/>"
<rect x="-75.0" y="-92.0" width="18" height="184" rx="9.0" ry="9.0" fill="gray"/>"
#mounting holes for studs in control cabinet
<circle cx="66" cy="83" r="3" fill="black"/>
<circle cx="66" cy="-83" r="3" fill="black"/>
<circle cx="-66" cy="83" r="3" fill="black"/>
<circle cx="-66" cy="-83" r="3" fill="black"/>
#panal flange with rounded corners
<rect x="-87" y="-75" width="174" height="149" rx="22" ry="22" fill="gray"/>"
#panal face with rounded corners
<rect x="-84" y="-72" width="168" height="143" rx="19" ry="19" fill="white"/>"
<circle cx="-55.05" cy="-43.05" r="19.95" fill="black"/>
<circle cx="-38.05" cy="-25.499999999999996" r="1.5" fill="black"/>
<circle cx="-72.05" cy="-25.499999999999996" r="1.5" fill="black"/>
<rect x="-65.8" y="24.5" width="21.5" height="27.5" fill="black"/>
<rect x="-73.35" y="-11.1" width="36.6" height="23.6" fill="black"/>
<rect x="-28.75" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="-9.7" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="9.35" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="28.4" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="47.45" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="66.5" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="-28.75" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="-9.7" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="9.35" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="28.4" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="47.45" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="66.5" y="-34.6" width="10" height="11.5" fill="black"/>
</g>
<g fill="black">
<circle cx="-10" cy="4" r="5"/> # power level potentiometer
<circle cx="-10" cy="44" r="6"/> # power auto-hand switch
<circle cx="24" cy="44" r="6"/> # safety override switch
<circle cx="56" cy="44" r="6"/> # manual fire switch
</g>
<g transform="scale(0.13,0.13)">
<use transform="translate(-230.0,-380)" xlink:href="#Fan"/>
<use transform="translate(-83.46,-380)" xlink:href="#Pump"/>
<use transform="translate(63.08,-380)" xlink:href="#Temp"/>
<use transform="translate(209.62,-380)" xlink:href="#Level"/>
<use transform="translate(356.15,-380)" xlink:href="#Laser"/>
<use transform="translate(502.69,-380)" xlink:href="#Control"/>
</g>
</svg>
</nowiki>
</pre>
[[Category: CheapChineseLaser]]

CCL front panel

2017-05-01T22:53:24Z

James: added category

<nowiki>
<svg width="174mm" height="184mm" viewBox="-87 -92.0 174 184">

<symbol id="Fan" fill="gray" >
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<symbol id="Pump">
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</symbol>

<symbol id="Temp">
<circle cx="65" cy="15" r="2.5" stroke-width="2" stroke="gray" fill="white"/>
<circle cx="50" cy="40" r="12" fill="gray"/>
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<circle cx="50" cy="40" r="9" fill="white"/>
<rect x="45" y="3" width="10" height="42" fill="white" rx="7" r="7"/>
<circle cx="50" cy="40" r="5" fill="gray"/>
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<circle cx="50" cy="25" r="2" fill="gray"/>
<line x1="50" y1="40" x2="50" y2="25" stroke-width="5"/>
<path d="M 5 60 q 15 10 30 0 t 30 0 30 0 v 10 q -15 10 -30 0 t -30 0 -30 0 z" fill="gray"/>
<path d="M 5 80 q 15 10 30 0 t 30 0 30 0 v 10 q -15 10 -30 0 t -30 0 -30 0 z" fill="gray"/>
</symbol>
<symbol id="Level" fill="gray">
<path d="M 0 20 v 65 a 15 15 0 0 0 15 15 h 70 a 15 15 0 0 0 15 -15 v -65 h -8 v 62 a 10 10 0 0 1 -10 10 h -64 a 10 10 0 0 1 -10 -10 v -62 z"/>
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<path d="M45 10 h 10 v 39 l 12 -12 7 7 -24 24 -24 -24 7 -7 12 12 z"/>
</symbol>
<symbol id="Laser">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<g transform="scale(0.9,1) skewY(10)">
<line x1="10" y1="40" x2="82" y2="40" stroke-width="5" stroke="gray"/>
<circle cx="88" cy="40" r="4" fill="gray"/>
<g transform="translate(88,40)">
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(-45)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(0)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(45)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(90)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(135)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(180)"/>
<line x1="0" y1="-8" x2="0" y2="-16" stroke="gray" stroke-width="5" transform="rotate(225)"/>
</g>
</g>
<g transform="scale(0.8,1) skewY(20)">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<circle cx="48" cy="48" r="4" fill="gray"/>
</g>
</symbol>
<symbol id="Control">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<g transform="translate(90,10) rotate(45)">
<path d="M 0 0 l -10 22 10 10 -10 25 10 10 0 20 10 -22 -10 -10 10 -25 -10 -10 0 -20 z" stroke="gray" fill="gray"/>
</g>
<g transform="scale(0.8,1) skewY(20)">
<rect x="0" y="0" width="60" height="90" fill="gray"/>
<rect x="5" y="5" width="50" height="80" fill="white"/>
<circle cx="48" cy="48" r="4" fill="gray"/>
</g>
</symbol>
<g>
<title>Control Panel</title>"
#background
<rect x="-87" y="-92.0" width="174" height="184" fill="black"/>
#mounting tabs
<rect x="57.0" y="-92.0" width="18" height="184" rx="9.0" ry="9.0" fill="gray"/>"
<rect x="-75.0" y="-92.0" width="18" height="184" rx="9.0" ry="9.0" fill="gray"/>"
#mounting holes for studs in control cabinet
<circle cx="66" cy="83" r="3" fill="black"/>
<circle cx="66" cy="-83" r="3" fill="black"/>
<circle cx="-66" cy="83" r="3" fill="black"/>
<circle cx="-66" cy="-83" r="3" fill="black"/>
#panal flange with rounded corners
<rect x="-87" y="-75" width="174" height="149" rx="22" ry="22" fill="gray"/>"
#panal face with rounded corners
<rect x="-84" y="-72" width="168" height="143" rx="19" ry="19" fill="white"/>"
<circle cx="-55.05" cy="-43.05" r="19.95" fill="black"/>
<circle cx="-38.05" cy="-25.499999999999996" r="1.5" fill="black"/>
<circle cx="-72.05" cy="-25.499999999999996" r="1.5" fill="black"/>
<rect x="-65.8" y="24.5" width="21.5" height="27.5" fill="black"/>
<rect x="-73.35" y="-11.1" width="36.6" height="23.6" fill="black"/>
<rect x="-28.75" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="-9.7" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="9.35" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="28.4" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="47.45" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="66.5" y="-63.0" width="10" height="11.5" fill="black"/>
<rect x="-28.75" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="-9.7" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="9.35" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="28.4" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="47.45" y="-34.6" width="10" height="11.5" fill="black"/>
<rect x="66.5" y="-34.6" width="10" height="11.5" fill="black"/>
</g>
<g fill="black">
<circle cx="-10" cy="4" r="5"/> # power level potentiometer
<circle cx="-10" cy="44" r="6"/> # power auto-hand switch
<circle cx="24" cy="44" r="6"/> # safety override switch
<circle cx="56" cy="44" r="6"/> # manual fire switch
</g>
<g transform="scale(0.13,0.13)">
<use transform="translate(-230.0,-380)" xlink:href="#Fan"/>
<use transform="translate(-83.46,-380)" xlink:href="#Pump"/>
<use transform="translate(63.08,-380)" xlink:href="#Temp"/>
<use transform="translate(209.62,-380)" xlink:href="#Level"/>
<use transform="translate(356.15,-380)" xlink:href="#Laser"/>
<use transform="translate(502.69,-380)" xlink:href="#Control"/>
</g>
</svg>
</nowiki>
[[Category: CheapChineseLaser]]

Cheap Chinese Laser

2017-05-01T22:51:56Z

James: added float switch file uploads on 5/1

[[Cheap Chinese Laser]]

This is the page dealing with the [[Cheap Chinese Laser]] at [https://www.hacdc.org HacDC] in the upstairs room at St. Stephen and the Incarnate church in Washington, DC. This page replaces [[PA LaserCutter]] page from some years ago. It had high ideals, but poor execution.

==Introduction==
HacDC has a K40, 40W, CO2, water cooled, laser for CNC cutting of various materials, aka a cheap Chinese laser. It allegedly used to work just fine, but someone decided that wasn't good enough so she ordered and halfass installed some new parts that only halfass work. After our intrepid hero, [[user:James|James]], fullyassed the installation of the new parts, the laser still only halfass worked. [[user:Tom|Tom]] was railroaded into helping with the software, but even so the dynamic duo couldn't get the damn thing to work. Then one day at work, boredom struck in a meeting and James had the idea to create this wiki page to guide others through the confusion and misinformation that plagues most equipment at HacDC and often results in subpar operation. I beseech you, dear reader, to continue your edification on our topic at hand and become your own evil archvillain with laser powers. (Sharks sold separately.)

==Components==
===Chassis===
The chassis is the laser itself, the blue metal box with 3 flip up lids. The main lid users deal with is for the cutting chamber on the left front of the machine. It includes an orange plastic window. The cutting chamber contains the transverse and longitudinal axes, aka x and y. X goes left to right, and y goes back to front. The material to be cut goes in this chamber. The second flip up lid is for the controls and power supplies chamber. This lid contains the front panel controls and indicators. There are two control boards, the Smoothie board and the K40 ACR plug-and-play board which connects the Smoothie board to the machine hardware. There are two power supplies as well, the control powersupply which is right below the control boards and the high-voltage (and I mean real high voltage, like around 15kV, not those nambypamby B.S. 120VAC "high voltage" warning labels) laser tube power supply which creates enough voltage to rip the electrons off the CO2 molecules and ionize them and cause them to emit coherent light when the electrons get back together with their matching CO2 ions. For more about this exciting process, read a science book. The third lid covers the laser tube chamber at the back of the chassis. You don't really need to mess with these last two lids unless you are modifying the equipment or troubleshooting a failure. All the lids have interlock switches and the laser will not fire if any one is open (unless you flip the override switch, in which case, it's your own darn fault for burning out your eye, as we say in Charlotte, "you did it to yourself").
===Exhaust===
The exhaust system sucks smoke from the laser chassis cutting chamber and sends it outside through a window. It was cobbled together using a fan and housing salvaged from a prior laser cutter and is mostly held together with zipties and metal duct tape. Seriously. I'm not kidding. Actual zipties and duct tape. (I'd like to give a shout-out to Home Depot for selling me the role of metal tape for only one cent.) If any part of the whole laser system is going to crap out, this would be a good part to bet on. It also uses 4" diameter (that's 105mm for those of you on the metric system) flexible metal clothes dryer exhaust duct to carry the exhaust gasses. There are custom-made, 3d-printed transiton pieces at the back of the laser chassis which replace the original feeble exhaust system. Read about them [[K40_Exhaust_Assembly|here]]

===Cooling===
The cooling system presently consists of a 5 gallon pail in the roller cabinet with a submersible pump. The water should be replaced with distilled. (The pump power cord got a new plug. It stays plugged in much better than the original cheap Chinese plug.) If the water doesn't flow, the laser will burnout. Sadness. The cooling system presently only works based on the heat capacity of the water in the bucket. Once the water heats up, you just need to wait for it to cool back down all by itself. You can read about other people with more sophisticated refrigerated cooling systems, but this was quick and easy, like a virgin on prom night. Julia has mentioned she's got some thermoelectric coolers in hiding for this project. We'll cross that bridge when we get everything else running first. The cooling system will have 3 interlocks: low water level, low flow, and high temperature.

===Computer===
This is CNC equipment. The first C is for Computer. (No, not for cookie, but we often have cookies anyway.) You need a computer with a USB port. You need computer software. I hope we can have a computer dedicated to the laser, but let's be real, that's not likely to happen. I hope Tom will fill out this section.
===Cabinet===
The cabinet is what the chassis sits on. The cabinet has wheels. It's made of particle board and painted white. The left door has upper and lower latches inside which hold it shut, so don't yank on it. The cabinet houses the cooling system, the power strip which all the line voltage equipment plugs into: exhaust fan, cooling pump, laser chassis, 12V power supply (not yet installed).

==Safety Interlocks==
'''None of these safeties are installed yet.''' Don't go futzing around with stuff unless you know exactly what you are doing. And tell James or Tom.
===Ventilation===
#Exhaust - If the exhaust fan isn't moving air, we don't want the laser to fire and make lots of smoke which would then fill the room
#Lens - Eventually we plan to install an air shroud nozzle around the laser lens to keep smoke from coating the lens and reducing cutting power.
===Coolant===
#Level -
#Flow
#Temp
===Doors===
#Cutting Chamber
#Control Chamber
#Laser Chamber - Probably not going to install this switch because the door is in back and control panel space is at a premium
#Cabinet - Probably not going to install this switch because there's not much harm in the cabinet and control panel space is at a premium

==Workflow==
===Prestart===
#Come up with design
#Create SVG using software like [https://inkscape.org/ Inkscape]
#Upload SVG to computer
#Convert SVG to toolpath using software like [http://www.scorchworks.com/LaserDRW_extension/laserdrw_extension.html Laser Draw]

===Startup===
#Roll cabinet out from under shelf
#Get extension cord out of cabinet and plug laser into extension cord and extension cord into live receptacle
#Turn on laser master power switch
#Close cabinet door
#Load material to be cut in laser cabinet
#Shut lid on cutting chamber
#Turn on laser cabinet power switch
===Operations===
#Ensure all safety interlocks are operable by checking indicator lights
#Run program without laser powered on to observe tool path and ensure material to be cut in properly arranged in the cutting chamber
#Run program with laser powered on to cut material
===Shutdown===
#Turn off laser chassis and master power switches
#Unplug laser and extension cord
#Coilup and store extension cord
#Shut cabinet door
#Roll cabinet back under the shelf
#Continue with your evil plans for world domination

==Custom Wiring==
Julia had some LED strips she wanted installed. We succeeded. The illuminate when the main power is turned on.
[[File:Laser-leds1.jpg]]

They are white LEDs but the orange laser viewing window colors them.

[[File:Laser-leds2.jpg]]

Sully really likes relays and discrete, analogue circuits, so he jimmied up a bunch of stuff to make it less likely for you to poke your eye out or burn out the laser.
The laser power supply from the factory takes input from 3 front panel controls: off-on laser switch, momentary-on laser switch, power control potentiometer knob. The off-on switch was a cheap latching push button which was connected to the leftmost two terminals of the 6 terminal plug with black wires. It was replaced with an off-on, metal, toggle switch on 3-23-17. The middle two terminals of the block connect to the momentary on push button switch on the front panel which causes the laser to fire (when the left two terminals are shorted together by the toggle switch). The right 3 terminals (which overlap with the right center terminal going to the push button switch) connect to the front panel potentiometer which controls the laser current. Do not turn the knob to full clockwise, because increasing the laser firing current past a certain point doesn't provide any benefit and just reduces the tube lifespan. The plan is to parallelize the push button firing switch with a solid-state relay controlled directly by the Smoothie board and bypassing the K40 ACR board (which was supposed to make the Smoothie board plug-and-play, but as mentioned earlier did a halfassed job). The potentiometer will be connected to a 3PDT switch for computerized or manual power level control. A PWM to DC circuit will do the automatic control and the original pot will remain for the manual control.
The safety interlocks are basically a whole bunch of microswitches in series so if any one of them gets tripped the left two pins of the power supply 6 pin connector won't be shorted together and the laser won't fire. There's also a plan to have lights illuminate to show which safeties are operating properly or tripped. Plus indicator lights are cool. And for the remaining manual firing switches we plan on getting those flip-up red covers like in those military movies where they're firing nuclear missiles and stuff like that. These would aid in troubleshooting, and look really cool, even if they are kinda spendy. Man, this is really turning into a wall of text. Someone should do something about this sometime. Anyway, schematic drawings would go here, or links to them would go here.

==Custom Parts==
Images of custom parts like the exhaust nozzles and eventually a new control panel and source files for 3d printed or laser cut parts can go here.

[[CCL front panel]]

[[Air flow switch holder]]

[[Exhaust nozzle]]

This image is colored for 3d printing using it as a height map: black=0mm, gray=1mm, white=2mm. 174mm wide, 184mm tall.
The SVG file was created by a Ruby program to modularize the positions and sizes of cutouts for switches, nobs, lamps, etc.

[[file:Control-panel.png]]

==Bill of Materials, a.k.a. Donation Wishlist, and Hardware Store Shopping List==
#Laser goggles
#USB A-B cord, i.e. printer cable, which doesn't suck
#Solid state relays -- we used [http://www.clare.com/home/pdfs.nsf/www/LBA110.pdf/$file/LBA110.pdf] this one. --This should move to custom parts and off the wishlist (JS 4-20).
#Stuff to cut
##1/8" Baltic birch plywood
##Plastic sheets, e.g. acrylic
##Masonite?
#Cabinet reinforcements
##dimensional lumber, e.g. 2x4, 2x2, 1x3
##unidirectional casters
#Cooling system stuff
##Distilled water
##Float switch
##Thermocouple or thermistor/RTD temperature sensor probe
##Radiator and fans
##Solidstate heat pump
##Working water fountain chiller (for future use on the 100W downstairs)
##PLC/Microcontroller with A/D inputs for temperature probe conditioning and temp display (advanced task)
#Green connectors for smoothieboard and laser powersupply

==To-Do Tasks==
#Receive new parts ordered April ?: machine screws and nuts for microswitches
#Airflow switch housing
##manufacture
##install
#Coolant interlocks
##Level sensor
###design
###manufacture
###install
##Flow sensor
###design
###manufacture
###install
##Temp sensor
###design
###manufacture
###install
#Hourmeter
##design
##install
#Door switches
##3d print v5 mounting block and install [[Door switch mounting block]]
##wire up switches
#Chassis wiring
##Mount one of the terminal strips and wire up the safety switches
##Draw a wiring diagram of custom components and label/number the terminals
#CNC firing control - This svg file can be used to test run the laser: [[Laser circle test]]
##find firing signal on Smoothie board
##determine relay requirements
##purchase and receive relay
##install firing relay
#CNC power control
##find PWM power level control signal on Smoothie board - PWM duration 300us
##fabricate converter - breadboarded and bench tested
##install converter
#software
##determine best software to use
##develop workflows for various programs and operating systems
##update this page to explain the above

==Completed Tasks==
If you do work on the laser, please record it here.
{| class="wikitable sortable"
|-
! Task !! Fixer !! Date !! Notes
|-
| Create Wiki page || [[user:James|James]] || 3/24/2017 || Ongoing updates needed
|-
| Install operational exhaust system || James || 2/2017 || Still needs interlocks
|-
| Install cooling system || James || 2/2017 || Air cooling or refrigeration could be added
|-
| Connect control power supply to switched mains || James || 3/2017 || Done
|-
| Get x and y axis movements working || [[user:Tom|Tom]] || 3/2017 || Firing still needs to be fixed
|-
| Replaced cooling pump power cord plug || James || 3/26/2017 ||
|-
| Installed door closure bolts on left cabinet door || James || 3/26/2017 ||
|-
| Installed cutting chamber illumination LEDs and 12VDC powersupply || James || 3/26/2017 ||
|-
| Control + interlock circuits design/brainstorm session || James + Tom || 3/27/2017 || See webpages below for Smothieboard help
|-
| Mocked up and tested control circuit for PWM from smoothieboard || James + Tom || 3/27/2017 || http://smoothieware.org/laser-cutter-guide
|-
| Scoped out various pins on the smoothieboard to find PWM out || James + Tom || 3/27/2017 || http://smoothieware.org/smoothieboard-v1
|-
| Removed control panel || James || 3/30/17 || Don't mess with nothing until a new one gets installed!
|-
| Tried to 3d print a new control panel || James || 4/2/17 || Lulzbot Taz either didn't extrude or made bird poop. :( It's too bad we don't have a working laser cutter.
|-
| Adjusted program size parameters based on failed print and added ammeter mounting screw holes to control panel design || James || 4/11/17 || Still need to upload new SVG here and print it
|-
| Ordered self adhesive cable tie mounting squares and SSR for PWM-> DC || Tom || 4/11/17 || Delivery expected Thursday
|-
| Design 3d-printed mounting bracket/clip to hold switches for door interlocks || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Design, breadboard and test PWM circuit with solid state relay and newly determined time constant || James + Tom || 4/15/17 || Impromptu Saturday night productivity session.
|-
| Uploaded exhaust nozzle and exhaust flow switch scad files || James || 4/20/17 || Flow switch needs printing and Tom's nacelle needs dimension tweeking.
|-
| Tried printing control panel on the Ultimaker2 || James || 4/25/17 || Print failed twice, but third time looked good before I left.
|-
| Installed control panel 3d printed on Tuesday || James || 4/27/17 || Controls and indicators are installed but not operational, yet. It looks sweet! Could be thicker, maybe 4mm. Dimensions could use tweeking too: toggle switches moved down, corner radii reduced,...
|-
| Uploaded source code and stl for float switch || James || 5/1/17 || Still need to print them.
|}

[[Category:Equipment]]
[[Category:LaserCutter]]
[[Category:Projects]]
[[Category:Ongoing Projects]]
[[Category:Project Awesome]]
[[Category:CheapChineseLaser]]

Float switch

2017-05-01T22:49:58Z

James: added links to stl files.

This is the source code for the float switch 3d printed parts for the water level detector for the [[Cheap Chinese Laser]].
It is made in two parts: the head and the base.
You also need 4 pieces of 1/4-20 all thread to connect the two of them and 8 nuts.
The base is internally threaded. The head needs nuts top and bottom. Washers would be good too.

[[File:Float-switch-head.stl]]

[[File:Float-switch-base.stl]]

stl files rendered on 5/1/2017

<pre>
/*
low water level detector
safety interlock for cheap Chinese laser at Hac DC
This water level detector is a two piece assembly connected by threaded rod. This model uses 1/4-20 rod. The lower foot has a 40mm home in the bottom to insert a pingpong ball as the float.
James Sullivan
4-30-17
Mk 2 - calculated threads
OpenSCAD version 2015.03-1
*/
ppbd=40; //ping pong ball diameter
ppbw=2.7; //ping pong ball weight in grams
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
wlh=200; //water level height
sbw=6; //switch body width
nfw=4; //nut face width, switch mounting nuts
nt=1; //nut thickness, switch mounting nuts
thick=5; //thickness
fph=thick*3;//foot pillar height
eps=0.1; //epsilon
tol=0.5; //tolerance
br=50; //base radius
rod=25.4/4; //rod outer diameter
tpi=20; //threads per inch
bfw=ppbd+2*thick; //base flange width
$fn=40;
function mod(num,den) = num - floor(num/den)*den;
//dimensions taken from Front Door Switch Holder
wr=4; //wrench size for nuts width across flats
nh=1; //nut height, depth of nut sockets
$fn=40;

//head
module head() {
difference(){
union(){
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,0]) cylinder(d=rod+thick*2,h=thick); //leg cylinders
}
cylinder(h=thick,r=ppbd/2+rod/2+tol-thick/2);
}
translate([0,0,-thick/2]) cylinder(h=thick*2,r=ppbd/2+rod/2+tol-3*thick/2);
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,-thick/2]) cylinder(d=rod,h=fph); //leg holes
}
}
translate([sbw/2,(ppbd+rod+tol-2*thick)/(-2),0]) cube([thick,ppbd+rod+tol-2*thick,thick]);
translate([sbw/2,shp/2,thick]) difference(){ //switch mounting block, aligned with z-plane and x-plane, centered on y-plane
translate([0,-shp/2-nfw,0]) color("green") cube([thick,shp+2*nfw,2*nfw]);
for (y=[-shp/2,shp/2]) {
translate([thick/2,y,nfw]) rotate([0,90,0]) cylinder(d=shd,h=thick*2,center=true); //screw holes
translate([sbw-nh,y,nfw]) union(){ //nut sockets
for (ang=[0,120,240]) rotate([ang,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
translate([sbw/2+thick,bfw/2-nfw-shp,nfw]) union(){ //center nut socket
cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([120,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([240,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
}

module socket(nd,tpi,tl,thick) {
ror=nd/2; //rod outer radius
pitch=25.4/tpi; //thread pitch in mm
td=pitch*3/4; //thread depth in mm
rir=ror-td; //rod inner radius
sor=ror+thick; //socket outer radius
vert= [for (ang=[0:360/$fn:720]) ang<=45 ? [cos(ang),sin(ang)]*rir : ang<180 ? [cos(ang),sin(ang)]*(rir+td*(ang-45)/135) : ang<=225 ? [cos(ang),sin(ang)]*ror : ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/135) : [cos(ang),sin(ang)]*sor];
path1=[for(p=[0:$fn]) mod(p,$fn) ];
path2=[for(p=[0:$fn]) mod(p,$fn)+$fn ];
linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
polygon(points=vert,paths=[path1,path2]);

}
}

//foot
module foot(){
difference(){
union(){
translate([0,0,thick/2]) cube([ppbd+2*thick,ppbd+2*thick,thick],center=true);
for (angle=[45:90:315]){
rotate([0,0,angle]){
translate([ppbd/2+rod/2+tol,0,0]) socket(rod,tpi,fph,thick); //pillar
translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
translate([br-thick,0,0]) cylinder(r=thick,h=thick); //foot
} //end rotate
} //end for
} //end union
translate([0,0,-eps/2]) cylinder(d=ppbd+tol,h=fph+eps); //ping pong ball entry
} //end difference
} //end foot module

head();
</pre>

[[Category: CheapChineseLaser]]

Float switch

2017-05-01T22:47:16Z

James: created page

This is the source code for the float switch 3d printed parts for the water level detector for the [[Cheap Chinese Laser]].
It is made in two parts: the head and the base.
You also need 4 pieces of 1/4-20 all thread to connect the two of them and 8 nuts.
The base is internally threaded. The head needs nuts top and bottom. Washers would be good too.
<pre>
/*
low water level detector
safety interlock for cheap Chinese laser at Hac DC
This water level detector is a two piece assembly connected by threaded rod. This model uses 1/4-20 rod. The lower foot has a 40mm home in the bottom to insert a pingpong ball as the float.
James Sullivan
4-30-17
Mk 2 - calculated threads
OpenSCAD version 2015.03-1
*/
ppbd=40; //ping pong ball diameter
ppbw=2.7; //ping pong ball weight in grams
shd=2; //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
wlh=200; //water level height
sbw=6; //switch body width
nfw=4; //nut face width, switch mounting nuts
nt=1; //nut thickness, switch mounting nuts
thick=5; //thickness
fph=thick*3;//foot pillar height
eps=0.1; //epsilon
tol=0.5; //tolerance
br=50; //base radius
rod=25.4/4; //rod outer diameter
tpi=20; //threads per inch
bfw=ppbd+2*thick; //base flange width
$fn=40;
function mod(num,den) = num - floor(num/den)*den;
//dimensions taken from Front Door Switch Holder
wr=4; //wrench size for nuts width across flats
nh=1; //nut height, depth of nut sockets
$fn=40;

//head
module head() {
difference(){
union(){
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,0]) cylinder(d=rod+thick*2,h=thick); //leg cylinders
}
cylinder(h=thick,r=ppbd/2+rod/2+tol-thick/2);
}
translate([0,0,-thick/2]) cylinder(h=thick*2,r=ppbd/2+rod/2+tol-3*thick/2);
for(angle=[45:90:315]){
rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,-thick/2]) cylinder(d=rod,h=fph); //leg holes
}
}
translate([sbw/2,(ppbd+rod+tol-2*thick)/(-2),0]) cube([thick,ppbd+rod+tol-2*thick,thick]);
translate([sbw/2,shp/2,thick]) difference(){ //switch mounting block, aligned with z-plane and x-plane, centered on y-plane
translate([0,-shp/2-nfw,0]) color("green") cube([thick,shp+2*nfw,2*nfw]);
for (y=[-shp/2,shp/2]) {
translate([thick/2,y,nfw]) rotate([0,90,0]) cylinder(d=shd,h=thick*2,center=true); //screw holes
translate([sbw-nh,y,nfw]) union(){ //nut sockets
for (ang=[0,120,240]) rotate([ang,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
translate([sbw/2+thick,bfw/2-nfw-shp,nfw]) union(){ //center nut socket
cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([120,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
rotate([240,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
}
}
}

module socket(nd,tpi,tl,thick) {
ror=nd/2; //rod outer radius
pitch=25.4/tpi; //thread pitch in mm
td=pitch*3/4; //thread depth in mm
rir=ror-td; //rod inner radius
sor=ror+thick; //socket outer radius
vert= [for (ang=[0:360/$fn:720]) ang<=45 ? [cos(ang),sin(ang)]*rir : ang<180 ? [cos(ang),sin(ang)]*(rir+td*(ang-45)/135) : ang<=225 ? [cos(ang),sin(ang)]*ror : ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/135) : [cos(ang),sin(ang)]*sor];
path1=[for(p=[0:$fn]) mod(p,$fn) ];
path2=[for(p=[0:$fn]) mod(p,$fn)+$fn ];
linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
polygon(points=vert,paths=[path1,path2]);

}
}

//foot
module foot(){
difference(){
union(){
translate([0,0,thick/2]) cube([ppbd+2*thick,ppbd+2*thick,thick],center=true);
for (angle=[45:90:315]){
rotate([0,0,angle]){
translate([ppbd/2+rod/2+tol,0,0]) socket(rod,tpi,fph,thick); //pillar
translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
translate([br-thick,0,0]) cylinder(r=thick,h=thick); //foot
} //end rotate
} //end for
} //end union
translate([0,0,-eps/2]) cylinder(d=ppbd+tol,h=fph+eps); //ping pong ball entry
} //end difference
} //end foot module

head();
</pre>

[[Category: CheapChineseLaser]]

File:Float-switch-head.stl

2017-05-01T22:41:33Z

James: See float switch base. This is the matching head. Category: CheapChineseLaser

See float switch base. This is the matching head.
[[Category: CheapChineseLaser]]