Old Laser Cutter

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Laser Cutter

40 Watt Full Spectrum Laser Cutter

Original Manual: Link to Full Spectrum's official manual

Laser Cutter Class syllabus and guide

Machine Info

  • Frame: Full Spectrum K40
  • Cutting dimensions: 320mm by 241mm (12.5" by 9.5")
  • Max stock height allowance: 34mm (1.34")
  • Laser focal distance (from lens bracket): 67mm
  • Controller: RAMPS v1.4 (running a "laser" version of Marlin firmware)
  • Laser: 40W CO2 700mm
  • Water pump with distilled water
  • Air compressor
  • Exhaust: Fume hood attached via 6" hose
  • Set up by Paul StPierre
  • Donated by Jim Bowes

How to use

Before using the laser cutter, you must first get training through an intro class or get signed off on it by the manager

The following is a handy reference for the steps to go from a design to the GCode that will run on the laser cutter.

Running the Laser Cutter (LightBurn)


These are instructions for how to operate our Laser Cutter using the LightBurn interface. LightBurn is both a design program as well as a laser control program. You can use it to create or import drawings, and in the same screen determine how the laser will burn/etch/cut the features on the screen.

Updated: 9/8/2021 by Alex N

Instructions for running the Laser Cutter:

  1. Start-up Procedure:
    1. Turn on the power strip. Located behind the laser cutter. This should turn on the Air Compressor, Water Pump, and Power Supply for the laser.
    2. Turn on the Fume Hood/Ventilation. The power switch/knob is on the fume hood.
    3. Grab the key from its hiding place and insert into the lockswitch, turn to the right.
    4. Open the LightBurn program (dragon icon).
    5. Load drawing file or create drawing in the program. Ensure it is aligned as you need it. Common practice is to align drawings to the bottom left corner.
    6. Go to the "Console" tab and hit the "HomeXY" button.
      • Note: if you hit one of the regular "home" buttons, the machine will lock up. If this happens, you can disconnect and reconnect the program by clicking on "COM3" towards the bottom of the screen, changing it to "COM1", then changing it back to "COM3".
  2. Setting up a cut:
    1. Place your material on the bed. Make sure it is well-aligned and parallel to the sides of the machine. Use a spacer tool to align to bottom left corner of cutting region if desired.
    2. Use the Laser Focus Ruler to set the height of the bed. Raise/lower the bed using the adjustment wheel underneath.
    3. Set your burn settings in the "Cuts" tab. Use some of the existing test burns for reference or make your own if your material is unique. Note: the settings for each color are saved from the last time the program was used, so double-check your settings to make sure they are what you want!
    4. Click "Start" and watch it go! It is safe to watch, the IR light from the laser is absorbed by the window. The regular light can be intense when doing a cutting operation however, so avoid staring at the bright light.
  3. While it is running:
    1. Never leave the laser unattended! Materials can catch fire!
    2. If there is a problem, hit the big red emergency stop button. Located on the top of the laser cutter. Please note that this cuts the power, but does not tell the software to stop the laser. To turn it off in the software, you can hit one of the "Test Fire" buttons in the "Console" tab.
    3. In the event of a fire, use the the fire blanket or the white dry-type fire extinguisher located near the machine.
    4. NEVER open the lid while the laser is on!
  4. When done using the machine:
    1. Turn off the power strip.
    2. Turn the keyswitch off and put key back.
    3. Clean underneath the aluminum honeycomb bed. Lift the aluminum honeycomb out and clean up any small pieces and residue left behind. (Plywood tends to leave a lot of residue underneath that can be cleaned with isopropyl alcohol).

Note: old instructions on using VCarve and Inkscape to produce GCode can be found here in the Discussion page on the wiki.



  • Units for drawing: when you hit play/start, if your units are in inches there is a glitch that makes the machine run incredibly slow. Make sure it is in MM units before starting.
  • Fill and Line mode: separate speeds for each operation found in different places, default for line is usually way too high
  • Homing: normal home button will freeze the machine, which is why there is a separate HomeXY button
  • Stopping: when you hit the stop button, there is a delay before it actually stops. If you need it to stop burning right away, use the small Laser On/Off button on the machine to disable the beam.


  • E-Stop: this will cut power to the motors and laser beam, but does not tell the software to stop. If you release the E-stop without telling the program to stop, it will continue going wherever it thinks it should be
  • Laser On/Off button: a handy button to disable the beam but let the motors move. Helpful for doing a test run to make sure it goes where you expect. Don't forget to check it before running your program
  • Resetting1: if the machine is unresponsive or you hit the regular Home button by accident, you can quickly reset the connection to the machine on the bottom of the screen where it says "COM3". Click and switch this to COM1 or another option, then switch back to COM3. Now hit the HomeXY button and see if it responds.
  • Resetting2: if the machine is still unresponsive and needs to be reset, you have to shut down the LightBurn program, then unplug the USB cord to the machine. Plug the USB cord back in, and re-open LightBurn.

Other potential issues:

  • Smoke accumulating in machine: stop immediately and determine what is wrong. Likely cause-exhaust hood is not on
  • Laser weak - lens or mirrors may need cleaning, or the tube may be getting worn out

LightBurn Video Guides:

Official LightBurn documentation

Highlights from LightBurn's documentation:

  1. Toolbars
  2. General Usage Hotkeys
  3. Creating Vectors
  4. Engraving Images
  5. Importing External Vectors


  • Vacuum the inside
    • The bed of the machine should be vacuum out regularly after cutting to clean up any small pieces that fall into the honeycomb.
  • Cleaning the lens and mirrors
    • Ask someone to show you how to clean these before attempting yourself!
    • A dirty lens can cause burnt gunk to build up and potentially crack the lens.
    • Here is a video from the ATX Hackerspace on cleaning their lens - How to Clean Laser Optics
  • Aligning the mirrors


Laser Cutter Materials (from ATX Hackerspace)

Original page There are a wide range of materials that our Laser Cutter can cut, etch or mark - but some simply don't work (eg metals) and some are extremely hazardous to either humans or the machine itself (eg PVC and Vinyl). It is therefore imperative that you check these lists before attempting to cut materials that you have not worked with before.

It is not always obvious which materials will work - for example: Polycarbonate/Lexan produces flames and lethal chlorine gas which will rapidly corrode this normally $10,000 machine into uselessness and which is extremely hazardous to the health of people nearby. Yet Acrylic - which looks, smells, feels and tastes just like Lexan - cuts smoothly and cleanly and is one of the best materials to use with the laser! So check and double-check what you're cutting.


WARNING: Because many plastics are dangerous to cut, it is important to know what kind you are planning to use. Make has a How-To for identifying unknown plastics with a simple process.

Material DANGER! Cause/Consequence
PVC (Poly Vinyl Chloride)/vinyl/pleather/artificial leather Emits chlorine gas when cut! Don't ever cut this material as it will ruin the optics, cause the metal of the machine to corrode, and ruin the motion control system.
Thick ( >1mm ) Polycarbonate/Lexan Cuts very poorly, discolors, catches fire Polycarbonate is often found as flat, sheet material. The window of the laser cutter is made of Polycarbonate because polycarbonate strongly absorbs infrared radiation! This is the frequency of light the laser cutter uses to cut materials, so it is very ineffective at cutting polycarbonate. Polycarbonate is a poor choice for laser cutting.
ABS Melts / Cyanide ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching on fire and leaving behind melted gooey deposits on the vector cutting grid. It also does not engrave well (again, tends to melt). Also, cutting ABS plastic emits hydrogen cyanide, which is unsafe at any concentration.
HDPE/milk bottle plastic Catches fire and melts It melts. It gets gooey. Don't use it.
PolyStyrene Foam Catches fire It catches fire, it melts, and only thin pieces cut. This is the #1 material that causes laser fires!!!
PolyPropylene Foam Catches fire Like PolyStyrene, it melts, catches fire, and the melted drops continue to burn and turn into rock-hard drips and pebbles.
Epoxy burn / smoke Epoxy is an aliphatic resin, strongly cross-linked carbon chains. A CO2 laser can't cut it, and the resulting burned mess creates toxic fumes ( like cyanide! ). Items coated in Epoxy, or cast Epoxy resins must not be used in the laser cutter. ( see Fiberglass )
Fiberglass Emits fumes It's a mix of two materials that cant' be cut. Glass (etch, no cut) and epoxy resin (fumes)
Coated Carbon Fiber Emits noxious fumes A mix of two materials. Thin carbon fiber mat can be cut, with some fraying - but not when coated.
Any foodstuff ( such as meat, seaweed 'nori' sheets, bread, tortillas... ) The laser is not designed to cut food, and people cut things that create poisonous/noxious substances such as wood smoke and acrylic smoke. If you want to cut foodstuffs, consider sponsoring a food-only laser cutter for the space that is kept as clean as a commercial kitchen would require.

Safe Materials

The laser can cut or etch. The materials that the laser can cut materials like wood, paper, cork, and some kinds of plastics. Etching can be done on almost anything, wood, cardboard, aluminum, stainless steel, plastic, marble, stone, tile, and glass.


Material Max thickness Notes WARNINGS!
Many woods 1/4" Avoid oily/resinous woods Be very careful about cutting oily woods, or very resinous woods as they also may catch fire.
Plywood/Composite woods 1/4" These contain glue, and may not laser cut as well as solid wood.
MDF/Engineered woods 1/4" These are okay to use but may experience a higher amount of charring when cut.
Paper, card stock thin Cuts very well on the laser cutter, and also very quickly.
Cardboard, carton thicker Cuts well but may catch fire. Watch for fire.
Cork 1/4" Cuts nicely, but the quality of the cut depends on the thickness and quality of the cork. Engineered cork has a lot of glue in it, and may not cut as well. Avoid thicker cork.
Acrylic/Lucite/Plexiglas/PMMA 1/2" Cuts extremely well leaving a beautifully polished edge.
Thin Polycarbonate Sheeting (<1mm) <1mm Very thin polycarbonate can be cut, but tends to discolor badly. Extremely thin sheets (0.5mm and less) may cut with yellowed/discolored edges. Polycarbonate absorbs IR strongly, and is a poor material to use in the laser cutter. Watch for smoking/burning
Delrin (POM) thin Delrin comes in a number of shore strengths (hardness) and the harder Delrin tends to work better. Great for gears!
Kapton tape (Polyimide) 1/16" Works well, in thin sheets and strips like tape.
Mylar 1/16" Works well if it's thin. Thick mylar has a tendency to warp, bubble, and curl Gold coated mylar will not work.
Solid Styrene 1/16" Smokes a lot when cut, but can be cut. Keep it thin.
Depron foam 1/4" Used a lot for hobby, RC aircraft, architectural models, and toys. 1/4" cuts nicely, with a smooth edge. Must be constantly monitored.
Gator foam Foam core gets burned and eaten away compared to the top and bottom hard paper shell. Not a fantastic thing to cut, but it can be cut if watched.
Cloth/felt/hemp/cotton They all cut well. Our lasers can be used in lace-making. Not plastic coated or impregnated cloth!
Leather/Suede 1/8" Leather is very hard to cut, but can be if it's thinner than a belt (call it 1/8"). Our "Advanced" laser training class covers this. Real leather only! Not 'pleather' or other imitations!
Magnetic Sheet Cuts beautifully
NON-CHLORINE-containing rubber Fine for cutting. Beware chlorine-containing rubber!
Teflon (PTFE) thin Cuts OK in thin sheets. See https://www.ulsinc.com/materials/teflon ; the issues listed in https://en.wikipedia.org/wiki/Polymer_fume_fever. Our laser cutter has ventilation but does not seem to exhaust everything so be extremely careful.
Carbon fiber mats/weave
that has not had epoxy applied
Can be cut, very slowly. You must not cut carbon fiber that has been coated!!
Coroplast ('corrugated plastic') 1/4" Difficult because of the vertical strips. Three passes at 80% power, 7% speed, and it will be slightly connected still at the bottom from the vertical strips.


All the above "cuttable" materials can be etched, in some cases very deeply.

In addition, you can etch:

Material Notes WARNINGS!
Glass Green seems to work best...looks sandblasted. Only FLAT GLASS can be engraved in our cutter. No round or cylindrical items.
Ceramic tile
Anodized aluminum Vaporizes the anodization away.
Painted/coated metals Vaporizes the paint away.
Stone, Marble, Granite, Soapstone, Onyx. Gets a white "textured" look when etched. 100% power, 50% speed or less works well for etching.

External Resources

Where to Find Materials

  • Inventables has acrylic sheet in many colors.
  • Laserable Rubber on Amazon
  • Woodcraft in Newington - thin plywood of various sizes
  • HomeDepot or Lowes - plywood, acrylic, and various other materials
  • JoAnn Fabrics in Newington- fabrics, acrylic, plywood, and various other materials

Shape Generators

These can help create common but complex shapes for you to work with like boxes, gears, and more.