Welcome to the L-Cheapo wiki page. This is where open source and community content is compiled to give makers more information on customizing and building their own L-Cheapo laser cutters.
Buying a L-Cheapo
If you want to just buy one, the L-Cheapo's latest revisions can be purchased on the L-Cheapo Product Page
The L-Cheapo Manual can be found here and other documentation can be found on the product page, or this wiki page.
The L-Cheapo FAQ is in the manual, but can also be found here.
As people design more and more mounts for 3D printers and other CNC machines, they will be collected here.
Installing and Setting up an L-Cheapo
- This is a guide on how to set up the L-Cheapo (any wattage) on most common 3D printers and engravers.
- Depending on your printer, add a header to the L-Cheapo's terminals. This will connect in place of your extruder's heater. I can only sell the L-Cheapo in the form of a kit, so I cannot do this for you. Usually, a female 100mil header will do.
- If you have a Mach3 compatible mill, Bernard Brault has written an excellent tutorial and app note.
- If you have a CNC tool with a spindle, rather than a 3D printer, the CNC Assembly instructions show how to switch between laser and spindle.
- Mount the L-Cheapo on your extruder, either by screws or zip ties.
- Lower the Z axis. If you have a kickstand, lower it in place.
- Screw the lens assembly on the bottom of the laser module almost all the way out - it should not come off (if it does, just screw it back in a little), but it should be all the way extended.
- Put your protection plate on the print bed, if you have one (if you don't, the laser will burn through Kapton tape, if you use it).
- With protection goggles on, disconnect your printer's extruder and connect the L-Cheapo instead.
- Send the M104 S100 command to your printer (or otherwise turn on the extruder heat). The laser will light up. If it doesn't, switch the + and - contacts around; the extruder heater is resistive, so there is no standard configuration for it. The L-Cheapo has a protection diode and is safe to connect backwards, although it won't work, so just try again with the connector flipped!
- Use the crown on the bottom of the laser assembly to focus the laser by screwing the lens back in. Optimal focal distance is 3 to 4 inches, depending on your printer or CNC setup. I recommend using a piece of paper or cardboard as the target - when you see smoke, your laser is focused!
- The white wire on the L-Cheapo is a PWM input: you can send your own PWM TTL signal, or tie it to the red wire if you are not using it. Either way, we STRONGLY recommend using it for a cover interlock switch for your printer!
- Send the M104 S0 command to turn the laser off. You're good to go!
- There's a sample video here
- Another sample video of the L-Cheapo setup is here Thanks to heathenxyt for making it!
- Does your board have a PWM output that is switched from the negative side, like RAMPS 1.4 boards do? See this schematic | Laser Adapter Schematic for a simple adapter that you can build.
- Want some hard data on focusing the lens? Check out the excellent analysis by Mark Swanson.
- NEW: The L-Cheapo doubles as an optical transmitter! Use this simple schematic to feed an audio signal into it. Set the bias to about 80/20 towards ground, and adjust from there. You can also send data, using the AudioSerial software. You don't even need the minimodem hardware, just set the bias lower and crank the gain all the way up! The easiest way to get this circuit is to buy a Velleman preamplifier kit and then add the capacitor and potentiometer. Video demo here.
Running your L-Cheapo
See the our product page for the latest manuals.
Here are notes from the developers.
Alternatively, you can use your existing 3D printing software!
- Make a new profile for your favorite software (Skeinforge, slic3r, Cura and so on).
- This profile should have Z scaling set to -1, so that the Z axis will move UPWARD as the cut proceeds.
- Layer height and filament size should be 0.05mm (roughly the effective beam width).
- Infill should be set to zero percent.
- Travel speed should be set as high as possible within your printer's capability; 3000mm/sec is a good starting point.
- Flow rate should be set to zero.
- Feed rate is used to control cutting; some values for materials follow. - Paper: 12mm/sec - Acrylic: 2mm/sec - Leather: 5mm/sec
- An "engraving" profile can be done by setting the slicer to only process the first layer.
- The profile should have appropriate start and end gcode. The M400 command is your friend here!
I draw the object in Sketchup and then use the "push" command to raise it to the height I want, then export to STL and slice normally. Be sure that your start/end gcode sets the Z axis to the proper focal length!
You can find my Skeinforge profiles here
You can find the slic3r settings here Many thanks to Taylor Stoll and Riley August for slic3r config work!
Building a L-Cheapo
DTR-LPF sells excellent diodes and optics, but you can NOT use their driver circuit for the L-Cheapo! You need something a little beefier, like my driver, the schematic of which you can find here.
The bill of materials is here and includes the heatsink and fan.
You will need to drill through the heatsink -- you can do that by hand, or print a jig for a drill press or drill guide for a better cut. It's very important that the laser module fit snugly into the heatsink, for good thermal conductivity. Apply thermal paste liberally! Some of the pictures don't have thermal paste, that's just to show where everything goes -- you want the paste to be there when you run the laser. https://www.youtube.com/watch?v=1olPQ63jgbc Video of the jig here.
The Assembly page shows you how to put it all together. Fan placement is important!
BY OPERATING A L-CHEAPO LASER, WHETHER BOUGHT AS A KIT OR BUILT FROM PLANS, YOU AGREE AND ACCEPT:
-You are old enough to vote in your country of citizenship.
-You know the potential hazards in using high power lasers.
-You will wear laser-eye-protection if available when operating the laser.
-You will use this device in a legal and safe manner.
-You relieve the seller from any liability arising from the sale or use of this component /device / item.
-You will NEVER aim this device at people or animals, even when out of focus. Much like with a firearm, assume that anyone not behind you is at risk.
-All items are made on REQUEST. However, we do offer a lifetime warranty - send the laser back and it will be repaired or replaced.