Laser Manual

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Revision as of 20:13, 5 August 2017 by Johnbrady93 (talk | contribs) (Who can use the laser cutter)
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Contact list


  • Scotty Allen (@scotty on slack)
  • Darryl (@augur on slack and freenode)
  • Ruth Grace (@ruthgrace on slack)
  • Kyle (@kylesewing on slack)
  • Trent (@robbintt on slack)

Who can use the laser cutter

Only people who have been trained by an official trainer can use the laser cutter, in order to prevent unintended damage to the machine, operator, and Noisebridge.

People that have successfully completed the class:

  • Scotty Allen (@scotty) - Trainer
  • Darryl McAdams(@augur) - Trainer
  • Ruth Grace Wong (@ruthgrace) - Trainer
  • Kyle Ng (@kylesewing) - Trainer
  • Trent Robbins (@robbintt) - Trainer
  • Henner Zeller (@hzeller)
  • Adrian Kelly (@akelly)
  • Nick Pisaro (@nickp)
  • Patrick O'Doherty (@patrickod)
  • John Foote (@rrmutt)
  • Naomi Most (@nthmost)
  • Joyti Jit (@joyti)
  • David Lopez (@davidlopez)
  • Sigma (no slack)
  • Steve Young (@fineline)
  • Collin Overbay (@cjoverbay)
  • Ryan (slack tbd)
  • J (@j)
  • Nemesis Contreras (@nemesisc)
  • Matt McKenna (@mpmckenna8)
  • Olivier (@olivier)
  • Juan (@jclavijo)
  • Dany (@danyq)
  • Andres Polit
  • Edward (@edwardlui531)
  • Ely Rodriguez
  • Devan Mitchell
  • Johnna Calvillo (@johnna)
  • Jeff Tchang (@tachang)
  • @jslack
  • AndyMC (@signal)
  • Mohammed (@mohammed)
  • Chris (@chris)
  • Joanna Ma (no slack)
  • Tim Walsh (@classictim)
  • David Afolabi (@davidafolabi)
  • Jeremy Llewellyn (no slack)
  • Steven Wilcox (no slack)
  • Robby Nevels (@robz)
  • Douglas (@greenshoos)
  • Yuki (@yukims19)
  • Sean Grove (@sgrove)
  • Vicky (@vickydee)
  • Jason (@redconfetti)
  • William Brown (no slack)
  • Joe Grasser (no slack)
  • Jenny Liu (no slack)
  • Amber Zertuche (no slack)
  • Jarrod Hicks (jarrod)
  • Renana Horesh (no slack)
  • Jonathan Friedman (no slack)
  • Beerit Goldfarb (no slack)
  • Yotam Daniel (no slack)
  • Karin Levi (no slack)
  • Drew Skillman (no slack)
  • Nick Hohman (@nohman)
  • Nathan Argetsinger (no slack)
  • Albert Tien (no slack)
  • Michaela Carmein (no slack)
  • Kadir Barry (no slack)
  • Lee Azzarello (@steelnivenson)
  • Lilah Kitty (no slack)
  • Kitty (no slack)
  • Alejandro "Alex" Leyva (no slack)
  • Stephen Tranovich (no slack)
  • Asya (@asyalit)
  • Barakah (no slack)
  • Manny (no slack)
  • Vera Dikoun (no slack)
  • Ronald Sebilo-Tibbits (no slack)
  • Dave Irwin(@daveirwin)
  • Kelsi N. Dunkelbarger (no slack)
  • Ethan Ep (no slack)
  • Akihiko Satoda (no slack)
  • Kevin Morris (no slack)
  • Drew Erny (@dperny)
  • Alex Ray (no slack)
  • Dave Walker (no slack)
  • Mitch Altman (@altman23)
  • Bogdan Vitoc (no slack)
  • Kai Habermann (no slack)
  • Chris Gervang (no slack)
  • Ian Griggs (no slack)
  • Islam El-Ashi (no slack)
  • Parul Desai (no slack)
  • Emma Bahroos
  • Paul Velasquez (no slack)
  • Stefanie Ku (no slack yet)
  • Veli Mattila (no slack yet)
  • Conrad Schuman (no slack)
  • Sterling Springgate (@sspringgate)
  • Rafael Send (no slack)
  • Roger Filmyer (@roger)
  • Tristan Horn (no slack)
  • Raymond Young (no slack)
  • Neil Bachers (no slack)
  • Charlie S (@Chaz)
  • Belinda (@belindamo)
  • Raneem (no slack)
  • Charlie E (no slack)
  • Dawn H (@dawn)
  • Trevor Lewellen (no slack)
  • Keyvan Shovir (no slack)
  • John Shen (no slack)
  • Calvin Rachuy (no slack)
  • Terris Poole (
  • Lizzie (@lizzie)
  • Marcos Oap (no slack)
  • Bob Stein (no slack)
  • Scott Albritton
  • Nicole Borgaard (@gaardn)
  • Aaron Elligsen (not yet slacked)
  • Meeks Baker (no slack yet)
  • Jacob Fenwick (no slack yet)
  • Stuart Mason (no slack)
  • Nathan Heidt (no slack)
  • Tracy Weiss (no slack)
  • Ewa Anna Szyszka (no slack)
  • Lizzy A (no slack yet)
  • SYA Warfield (no slack yet!)
  • Dan Lipsitt
  • Dara Kosberg (no slack yet)
  • Terence Goldberg (no slack)
  • Dan Cooper (no slack)
  • LUS KA
  • Noah Swartz
  • Danielle Baskin
  • Jervon Graves
  • Rachel Fong (@rfong)
  • Blake Griffith
  • Joe Meissler (stickperson on irc)
  • Leslie Mueller (no slack)
  • Allison (no slack)
  • Kincaid Kawananakoa (
  • Victoria Fierce (@tdfischer)
  • Mike Roderick (no slack)
  • hannaH Cauldwell (no slack)
  • Grzegorz Biesiadecki (no slack)
  • lloyd pollock(no slack)
  • Edward Shively (no slack)
  • Kyle Morris (no slack)
  • Rae Parnmukh (no slack)
  • Joe Kniss (no slack)
  • Oskar Garcia (no slack)
  • Nanu (no slack)
  • Lawrence Kesteloot (no slack)
  • Warren Cheng (no slack)
  • Dot Richards (no slack)
  • Alexander Lin (no slack)
  • Melanie Day (no slack)
  • Tara Brooks (no slack)
  • Sam Lanning (@sam)
  • Manish (@manishearth)
  • Shane Lillya (no slack)
  • Jason Yosinski (no slack)
  • Chetan Verma (no slack)
  • Eyal Aklimi (no stack)
  • Chloe Revery (no slack)
  • Eran Rundstein (no slack)
  • Tommy Payne (no slack)
  • Luke Daenen (no shlack)
  • Quintessa (@super.lucky)
  • Haddox (no slack)
  • Chris Venter (@chrisv)
  • Lady Red (@mcscope)
  • Ashley Mishoe (no slack)
  • Jan Neumann (no slack)
  • Frank Crooks (no slack)
  • Brittany Carrico (no slack)
  • Joe Attokaren (joeat)
  • Jacob Powers (powersjcb)
  • Mark Willson (@mark)
  • Jonas Karlsson (@jsk)
  • Jessica Furst (no slack yet)
  • Jeremy Rollinson (@rollinson)
  • Clayton Lowell
  • Anastasia Victoria
  • Bruce Jahn
  • Wendy Qi (no slack)
  • Tal Oppenheimer (no slack)
  • Elaine Doyle (no slack)
  • Charley Walton (no slack)
  • Aleksandr Kudriavtcev (no slack)
  • James Lynch (no slack)
  • Alex Alekseyenko (@intron)
  • Michael Parisi (no slack)
  • Kynan Lalone (no slack)
  • Nick Fung (no slack)
  • Leah Bell (no slack)
  • Michael Micheletti (no slack)
  • A. Bulnes (no slack)
  • Senthil Arivudainambi (no slack)
  • Olga Namsaraeva (no slack)
  • Natasha Lerman (no slack)
  • Drew (@drwdal on twitter, no slack)
  • George (george_ashworth on irc)
  • TJ (no irc or slack)
  • Jonathan Schoonhoven (@jonathan)
  • Ad (Adalyn) Naka (no slack)
  • Katya Radul (no slack)
  • Guilherme Carvalho (no slack)
  • Aneesha Punreddy (no slack)
  • Brahmi (no slack)
  • Chris Swimmer (no slack)
  • Kelly Albrink (@privileged on slack)
  • Dave Chan (@davechan1)
  • Alex Duesman (no slack)
  • Samantha (no slack)
  • Tom Nevin (no slack)
  • Elena Nadolinski (no slack)
  • Pamela Fox (no slack)
  • Noah Katz (no slack)
  • Heather Mason (no slack)
  • Sasha (@sasha)
  • Sida Li (no slack)
  • Ali Lakrakbi (no slack)
  • Merlin (no slack yet)
  • Yuriy Pestov (no slack)
  • Or Oppenheimer (no slack)
  • Chloe Ng (no slack)
  • Nicole Kim (no slack)
  • David Brooks (Slacker)
  • Rodrigo Menezes (no slack)
  • Natalya Robinson (no slack)
  • Elias Lawson-Fox (@eliaslfox)
  • Ting Yit Wee (@weetinygit)
  • cedar q waxwing (no slack yet)
  • Mary Chenoe Hart (no slack)
  • Alden Michaels (slackin)
  • Kate Rudolph (no slack)
  • Miguel Cervera (no slack)
  • Jeremiah Davis Brown
  • CAIN Ray, (AKA Robot)
  • Raphael Palefsky-Smith (no slack)
  • Theodore Hilk
  • Tien Yin Yau
  • Jess H
  • Av (@Av)
  • catthu
  • Michael Chang
  • Scott Coates
  • Rich Arakelian
  • Carl Roett (alchemist)
  • Peter Ross Wagner
  • Alexander Alshanetsky
  • Jay Zuerndorfer
  • Nobel Yoo
  • Andy Grosser
  • Zach
  • Erik Aylen
  • Brendan Clarke
  • Cinna Lee
  • Dora Chen
  • Tiana Chan
  • Duncan Cai
  • Christine Tran (ctine)
  • Nicole Klau
  • John Brady (johnb)
  • Jacqueline (Oh Happy Day)
  • Max Chao
  • Dominic D
  • Troy Deck
  • Negash A Asegde
  • Kerrick Staley

How to get trained to use the laser cutter

  1. Ask a trainer if they will train you
  2. Schedule a time with the trainer
    1. The laser training class size is limited to 5 students, so that everyone can see how to operate the laser.
  3. Get trained
  4. Get your name on the list of users before the first time you use the machine

The laser training class is pay-what-you-can, and the recommended minimum donation is $20.

Basic Safety

The laser cutter is generally a very safe machine to use. However, as with all industrial machines, you need to treat it with respect. The main safety concerns are creating fires, hurting your eyes or skin, getting crushed by the machine, and creating toxic fumes.

The basics:

  • OPEN THE LID if you see a fire
  • BLOW IT OUT if the fire keeps burning


Laser cutter with water and estop
The water squirt bottle is sitting on top of the laser, and the estop is the round red button.

You can really hurt yourself or burn the building down with this machine. If you follow the safety rules, the chances of you causing this is close to zero. Some materials are very flammable on the laser cutter, and shouldn't be cut. Never cut an unapproved material, or a material you can't identify. A laser beam can also initiate a fire if the speed of the cut is too slow or the laser power is set too high.

Ways to not cause fires:

  • ALWAYS WATCH THE LASER CUTTER WHENEVER IT IS CUTTING AS FIRES CAN HAPPEN. The laser affects your material by heating it. Your job can change in seconds with the accumulation of heat in your material. Never leave the room while the laser is in operation. If you leave the laser unattended, your access to the laser cutter will be permanently revoked.
  • Use reasonable speed/power settings. Start with the recommended speed/power settings for your material. Be patient - resist the temptation to crank the power and speed to rush through your job. This can cause fires.
    • There will be some light when material is cut. This light at the point of lasing may be ok as long as it stays with the motion of the laser. If a flame appears while the laser is in operation, stop your job and try again with lower heat settings.
  • Know where the fire extinguisher is in case of a fire. The ONLY fire extinguisher that should be used on the laser cutter is the halotron extinguisher right next to the laser cutter. Other fire extinguishers are corrosive and will ruin the machine.

How to put out a fire:

  • Push the estop. (To turn the machine back on after the estop was hit, you need to switch the power switch on the right hand side of the machine off and on again).
  • Open the lid.
  • If it's small, try and blow it out.
  • If it's smallish, try and squirt it out with the water squirt bottle sitting on the right hand side of the machine.
  • If that doesn't work, use the halotron fire extinguisher to the right of the laser cutter. Aim it at the base of the flame.

Damage to eyes and skin

The laser beam can instantly and permanently blind you. It can also burn your skin.

  • You don't ever want any part of your body in contact with the beam.
  • As long as the door is closed, you're safe to look at the laser. There are interlocks on the door that help ensure the laser never operates with the doors open. Don't disable them.

Crushing danger

The laser cutter is a dumb machine. It doesn't care whether your hand is in the way when it's moving. The head can move when the door is open. Always make sure everyone's hands are out of the machine before moving the head.

Also be very careful not to crash the head into other parts of the machine. Be very careful when moving the z-axis to not crash the head into the bed, and to not move the z-axis if the focus length acrylic circle is under the lens.


The laser cutter burns the things it's cutting, which can create toxic fumes.

  • ONLY CUT APPROVED MATERIALS. Cutting nonapproved materials can release really toxic gases, including chlorine and cyanide. These are really bad for humans, as well as being very damaging to the laser cutter.
  • The ventilation fan should always be running if the laser cutter is on, even if it's not cutting. It's currently wired such that you can't turn on the laser cutter without the fan turning on, but please make sure it's running.

Care of the machine

Please don't perform any maintenance on the machine (including cleaning lenses/mirrors or aligning mirrors) unless you've specifically trained on it.

The laser cutter is finely calibrated piece of machinery. Please close the lid gently, and do not push or jar the machine at any time. Do not lean or press on the tray - it's fragile, and needs to be perfectly flat for the laser cutter to cut properly. If you take the honeycomb bed or slats out, please be ULTRA CAREFUL with them - put them somewhere where they won't get damaged or warped.

Paying for your laser time

The laser cutter has parts that wear out over time, which can be quite costly to replace, especially the laser tube. A new tube costs several thousand dollars. Thus, we require people to pay for the time on the laser they use, so we can pay for new parts. The cost for using the laser cutter is $5 per hour of cutting time.

To figure out how much time your job takes, press the File button, select your file, and then select Work Time from the menu. It will tell you in hours:minutes.seconds.

There is a laser cutter donation box on the wall of the Sparkle Forge room. Please pay for the cutting time you actually use, even if you end up running your job multiple times.


Overall Workflow

This is the overall structure of the workflow. Each part is elaborated below.

  1. Laser start up
  2. Material setup
  3. Convert file to DXF
  4. Load file onto the machine
  5. Dry run
  6. Cut/Engrave
  7. Laser shut down
  8. Cleanup

Laser start up

Laser chiller
The laser chiller is the box on the bottom left of this photograph. If the laser doesn't beep when it turns on, you should turn on the chiller manually.
  1. Turn on power and ensure that the fan and chiller are running. If you do not hear beeps when the laser starts up, the chiller is not running and you must turn it on.
  2. Move the head as far forward and right as possible, close to the controls

Material setup

  1. Clean the bed of any scraps that may be on it
  2. Move the cut head as far forward and right as possible (near the controls)
  3. Raise the laser head as far up as possible
  4. Raise the bed to the desired height, watching the laser head to avoid crashes
  5. Move the laser head as far back and right as possible
  6. Place material on the bed
  7. Focus the laser (do at least for each distinct thickness, optimally do for each piece of material)

Focusing the laser

Shelf by laser cutter
This is the shelf to the left of the laser cutter. The acrylic disks used for focusing the laser are in the toolbox with the yellow lid.

Noisebridge has acryllic disks cut to various thicknesses that can be used to accurately focus the laser. Specifically the laser head needs to be locked to 8mm above the surface of the material you're cutting.

  1. Place the material on the cut bed
  2. Move the cut head to the center of the area to cut, watching the laser head to avoid crashes w/ material
    1. Note that the honeycomb bed can move up and down (Z-axis) so if the material doesn't fit under, hit Z/U on the laser controls and navigate the menu until Z axis (or something similar) is selected. Then use the left and right arrows to move the bed up and down.
  3. Loosen the wing nut and raise the head all the way up
  4. Place the focusing discs on the material under the head
  5. Lower the head until it just touches the focusing disc (8mm above material)
  6. Lock the head in place (tighten the wing nut)
  7. Remove the focusing discs

Convert an image in Inkscape to a DXF file

  1. Load the image into Inkscape
  2. Set the different cut paths to different colors (for controlling settings, etc.)
  3. Perform any debugging steps (by default you should perform all of them b/c of errors in the laser software)
  4. Save as a DXF. Be sure to make the units be millimeters so that importing later will correctly scale the image.

Debugging DXF Problems

Sometimes exporting to DXF introduces bizarre extra lines. There are two things to try to debug. The first is to convert objects to paths:

  1. Select all the problematic shapes
  2. Path > Object to Path

If this fails to resolve the issue, you can try a more radical solution which will eliminate all bezier paths entirely:

  1. Select all the problematic shapes
  2. Convert bezier paths to lines (Extensions > Modify Path > Flatten Bezier).

Flatness 0.5 is good to start with. Smaller = better approximation of the curves. A lower flatness number takes more time to compute, but also produces a better approximation to the curve.

Sometimes need to select the path's directly with the path tool (but not the points!).

Also see for conversion from svg to dxf files.

Loading into the laser cutter software

  1. Import the file with File > Import
  2. Resize as needed, tho if the file was exported w/ millimeter units, the software should also import the image with the correct size.
  3. Set the cut order:
      • EITHER Set the cut order to inside-out (Handle > Cut optimize > Inside to outside)
      • OR Manually specify cut order with the Set cut property tool (Edit > Set cutting property). See below for more details.
  4. Set the speed and power for the layers as necessary, and the process mode for each layer to either cut (for continuous line cutting) or dot (for dashed line cutting) or scan (for engraving)
  5. Optionally, simulate the cutting/engraving process.
  6. Download to the machine (Laser Work panel on the bottom right).

Manually specifying cut order

In the Set cutting property window (Edit > Set cutting property), you can manually re-order the cut paths. In the window, you'll see an image of the workpiece, and to its right, two lists of paths. When you first open the window, all of the cut paths are in the left. If you select a path (either in the image or in the list) and click the button labeled ">>", this path will be transferred to the end of the right list of paths. If you click ">>>", all of the paths in the left list will be moved to the end of the right list (preserving order). Similarly, clicking "<<<" will move the right list to the end of the left list. If you select a cut path in the right list, the up and down arrow buttons will reorder that path in the chosen direction.

Loading speed and power settings from library

  1. In the top right panel, double click the layer of interest
  2. Click "Load parameters from library"
  3. Select the library item
  4. Click "Load"

Saving power and speed settings to library

  1. In the top right panel, double click the layer of interest
  2. Make sure the layer is set to the desired parameters
  3. Click "Load parameters from library"
  4. Click "Save as"
  5. Enter a name and optionally some notes
  6. Click "Ok"


  1. Open the simulation window with either Edit > Preview or the toolbar button labelled with a monitor.
  2. Click the Simulation button in the right panel


  1. Select the file to use using the File button
  2. Move the head to the initial guess origin with the arrow buttons
  3. Test the frame with the Frame button adjust origin as necessary
  4. Set the origin by pressing Origin
  5. Test the cut by turning the laser power off and pressing the Start/Pause button
  6. Turn the laser power on
  7. Cut by pressing the Start/Pause button


In the laser software, open the layers you wish to engrave in the layer parameters panel, and send the processing mode to "Scan". This will do a raster scan of the region bounded by the paths in that layer. An even-odd rule is used to assign regions to the "inside" vs "outside" of the engraving.

Cancel a cut/dry run

  1. Pause with the Start/Pause button
  2. Cancel and move back to the origin with the Esc button

Laser shut down

  1. Move the head as far forward and right as possible (near the controls)
  2. Raise the laser head as far up as possible
  3. Let the fan run for a little bit (~30 seconds)
  4. Turn the power off


Laser bottom tray
This is the bottom tray of the laser, which should be cleaned out after use.
  1. Remove pieces of material scrap left on the bed
  2. Open the tray door on the front bottom and empty the scraps left there

Calculating work time

On the computer:

  • Open the simulation window (see above). Total work time and time of laser use are displayed in the top right. Donations should be calculated by laser use, not total work time.

On the machine:

  • Whole file: File > Select file > Right Arrow > Work Time > Enter
  • Current run: Pause the cut, then check time at the bottom right

Fusion 360

Fusion 360 is a free CAD (Computer Aided Design) program from Autodesk for designing 3D parts, and arguably the best one currently available. If you're designing something complex on the laser cutter, particularly with multiple parts that need to fit together, I highly recommend it over drawing programs like Inkscape. It also has CAM (Computer Aided Manufacturing) capabilities, which makes it very useful for CNC machining and laser cutting. There's a copy of the software on the laser cutter computer, and you can download it here. It's free as long as you make less than $100k per year using it.

Workflow 1: The Quick and Dirty Way

This is the fastest way, and works a lot of the time

  1. Make sure your sketch only contains straight lines, arcs, and circles, and no spline curves. If your sketch has splines, go to #Workflow 3: The Long Way
  2. Make sure your part is designed using a single sketch, and that you want to cut all the lines in that sketch. If not, go to #Workflow 2: The Middle Ground
  3. Right click on your sketch and click Save As DXF
  4. Import the DXF in RDWorks, and continue with the standard workflow starting at #Loading into the laser cutter software

Workflow 2: The Middle Ground

If you're not sure, this is probably where you should start.

  1. Make sure your sketch only contains straight lines, arcs, and circles, and no spline curves. If your sketch has splines, go to #Workflow 3: The Long Way
  2. Right click on the top surface of the part you want to cut, and click Create Sketch
  3. Hit the P key to open the Project dialog box, then select the top surface of your part, and any other lines you want to cut
  4. Hit OK, then remove any lines you don't want cut
  5. Open the Sketches folder near the top of the tree, then right click your new sketch and click Save As DXF
  6. Import the DXF in RDWorks, and continue with the standard workflow starting at #Loading into the laser cutter software

Workflow 3: The Long Way

This allows more complicated things like exporting splines, which doesn't work with the above methods, kerf compensation, which makes your parts fit together snugly, but you can also use the above methods and then do it in RDWorks, or lead-ins and lead-outs, which can make for a cleaner cut, but I can't figure out how to get RDWorks to import correctly.

  1. Design a part to be laser cut by drawing a 2D sketch and extruding it
  2. Go to the CAM workspace by clicking the Model button in the top left, then selecting CAM
  3. Select the Waterjet operation (if you don't see this, turn it on under Preferences -> Preview)
    1. Set Type to Laser Cutting
    2. Select the Cutting Mode, either Through - Auto or Etch
    3. Look up the kerf of the material you're cutting in the #Known good materials section, and enter that in Kerf Width, or if your material's not listed, cut one a kerf gauge and put the result in the wiki. The kerf changes depending on the thickness, speed and power. Setting a larger kerf width will make your parts fit tighter, and setting a smaller kerf will make them looser.
    4. Select the contours of your part that you want to cut
    5. Go to the Passes tab, and change Compensation Type to In Computer
    6. Hit OK to close the dialog box, and you can see a preview of your tool path. You can go back to edit it by double clicking the contour operation in the tree on the left
  4. To export to DXF, click the Post Process button, which says G1 G2. Make sure rdworkslaser is selected as your post processor, type a name for the export and hit Post. Then select the folder to put it in.
  5. Import the DXF in RDWorks, and continue with the standard workflow starting at #Loading into the laser cutter software
  6. Fusion automatically orders the cuts from inside out and in the fastest order, but RDWorks doesn't always respect that order, so you may need to optimize the cut order again

Advanced Options

  1. If you're using your own computer for the first time and not the laser cutter desktop, you have to enable the laser cutter support which is still in beta, by clicking on your name in the top right, then Preferences, Preview, and checking "CAM - Waterjet/Laser/Plasma cutter support". You will also need to download the custom post processor that we use for this laser.
  2. There's a simulate button to the left of the Post Process button, if you want to do it in Fusion
  3. If you want to disable or tweak the lead ins and lead outs, you can go to the Linking tab. Lead ins and lead outs can fix the bump you get on the side of your part where the laser started and stopped, but they also make extra cuts in your scrap material, which you may want to keep. In this tab you can also specify the Entry Position for each cut path.
  4. You can disable Kerf Compensation by settting Sideways Compensation to Center under the Passes tab, though this is not recommended


Text Cutting

In Inkscape, after converting the text object to a path, it's necessary to ungroup the text as well, to create separate paths, prior to flattening the bezier curves.

If you're using a cursive font and want everything to be one piece, convert the text object to a path, and use Path > Union. This tool in general is quite useful for merging paths that have been independently drawn but need to be merged into a single path. For example, if you made two overlapping circles, without this the cutter would just cut the two circles, which leads to a lemon-shaped piece in the center. If you union the paths, it will cut an outline as well. Path > Union will not make any holes in the figure go away, it only gets rid of cuts passing through area covered by another shape.

Engraved text requires no other special technique because no cuts are made, but text cutting is non-trivial. Because of loops, it's sometimes desirable to use a stencil font, especially at smaller scales where legibility is important. 1001 Fonts has a number of stencil fonts for free. At 10pt, some good fonts are Marsh, Spacedock, and Allerta.

Negative Space Engraving

You can engrave a vector shape with a hole in the middle of it, so that you get enclosed portions that are not engraved in the middle of fully engraved portions. To do this, when you construct the image in your editor of choice, simply perform subtraction between the relevant paths, to remove the inner part. In the RDWorks laser software, the two paths will show up, and be independently editable (making them look like just two distinct paths to engrave), but they will engrave correctly as a negative space. Obviously test this w/ your software; this technique is known to work using Inkscape.

Kerf Compensation

For any given layer, you can compensate for the kerf (width of the cut) by opening it's settings and clicking the "Advance" button next to the "Seal" input box towards the middle-bottom. Enable sew compensation, and pick the direction and sew width (kerf size). The inward direction will make the actual cut move toward the inside of a closed cut path, outward will move it towards the outside.

In general, for cuts on the outside, you want to move outward, to move the actual cut edge be exactly where the path is in your design. For cuts on the inside, you want to use the inward direction.


File doesn't appear in laser cutter after successful download

If the laser cutter has 99 files loaded into it, new files will not show up. To fix this, open up RDWorks8, and on the right side, select the Doc tab. Inside that tab, click Read to read all the files in the laser cutter, and then click Delete all.

read files
This is the button used to read stored files from the laser cutter.
delete all files
This is the button used to delete all stored files from the laser cutter to make room for new ones.


Please don't perform any maintenance on the machine (including cleaning lenses/mirrors or aligning mirrors) unless you've specifically trained on it.

  • TEMP note: some check(s) may be included outside of maintenance so a user can trigger a maintenance notification
  • DON'T - let someone who has been trained do it
  • how to tell if the lens is dirty (or getting old?)
  • how to tell if the mirrors are dirty
    • Cleaning the mirrors
      • ethanol solution? isopropanol? - see manual.
      • fabric must be non scratch - see manual.
  • Checking and performing mirror alignment
    • Safety - remove gratings and any other reflective surfaces before any maintenance that requires disabling the door sensors.
    • TEMP note: in restrospect the alignment was a very dangerous situation. mirror paths were not checked before powering on the laser with the door open with many people around. (or maybe nigel is just insanely good at configuring mirrors... still...
    • Tape test - mirrors 1,2,3 and their corresponding exits. Slightly propped laser tube.
    • vertical/horizontal alignment by brass dial.
  • Checking chiller tank water volume
    • Chiller alarm - what does it mean
    • Checking tank water volume
    • Refilling tank water
  • Cleaning the bed and waste drawer (this section probably should be moved to usage)


  • Don't open front/back passthrough doors (for now)
  • Fire extinguishers - which to use for what fire
  • Approved materials
  • careful when raising bed, dont crash into laser head
  • move laser head out of the way before opening the lid
  • power off the laser before opening the lid ???
  • watch the laser while it is cutting


  • Move the machine further away from the right wall so we can get to the power switch.
  • label the water squirt bottle as for fires and not to remove
  • acquire piece of copper for chlorine materials test
  • acquire vinyl record for testing
  • acquire propane bottle and nozzle

material notes

  • material selection - approved materials list
    • nothing that generates hazerdous fumes, particularly chlorine/formeldahyde
    • no aluminum or other metals (?? ryan claims these can be safely engraved in this machine)
    • nothing reflective
    • size constraints
  • laser configuration - power, speed
    • table of recommmended settings for various materials

How to get a new/novel material approved

  • consensus process
  • chlorine test

Chlorine material test

Before you cut any new material you *must* check that it is safe to cut; specifically that it will not produce chlorine gas when it is burned by the cutting laser. Chlorine is extremely dangerous in its gaseous form and so must be avoided at all costs.

To test a new material, you'll need a sample of the material, a small copper rod (about the thickness of a coat hanger), a pliars, and a handheld propane torch. We'll test for the presence of chlorine by burning a sample of the material in a high temperature propane flame and observe the visible emission spectra. Chrlorine produces a bright green light when burned, and so will be very obvious when you're testing your material.

First, turn on the ventilation on the Sparkle Forge. The switch for this is under the sign that says "For Non-Laser Fires Only", and above the non-laser fire extinguisher. Then, light the propane torch and set it to rest upright on a stable surface. Taking the pliar, hold the piece of copper in the blue part of the flame to heat it. As the copper begins to heat sufficiently it'll cause the flame to turn an orange color. A consistent orange color means that the copper has no residue material on its surface and so is clean enough to use as a test. If you observe non-orange flames when you burn the copper you may need to clean in further, either by waiting for the excess material to burn off, or by scrubbing the surface of the copper when it has cooled.

Once the copper is burning, take the hot copper and melt a sample of the new material onto it. For example if you were testing a new form of plastic you can roll the hot copper rod on the material, melting some of it onto the copper rod's surface.

With this done, place the copper rod back into the blue part of the flame. Observe the colors of the emission spectra from the new material burning. If you observe a bright green color, then the material contains chlorine and thus *must not* be burned further. Ventilate your surrounding area to avoid breathing it in. If you observe no green color as you burn your material sample, then the material is likely safe to use with the laser cutter.

Here is a video example by Zach in NYCResistor with a known good and known bad material:


These materials must not be used in the laser cutter.

Bad materials
Material Notes
PVC Contains chlorine. Will produce hydrogen chloride gas when used which is extremely toxic and also damages the laser optics.
Vinyl Most contains chlorine. Will produce hydrogen chloride gas when used which is extremely toxic and also damages the laser optics.
PVC Foams Most contains chlorine. Will produce hydrogen chloride gas when used which is extremely toxic and also damages the laser optics.
Foam Core Usually made with PVC which is harmful as listed above.
Styrofoam Can cause flash fires
Polycarbonate or PETG Does not cut. TAP plastics sells both this and acrylic. Be sure to read your labels when purchasing material. Lexan is the trade name for Polycarbonate, while Plexiglass is the trade name for acrylic.
ABS Gives off hydrogen cyanide which can kill you and also may damage the laser optics.
Fiberglass Contains complex epoxies which will cause fires, chlorine, and cyanide. Also contains glass which will not cut.
Metals Cannot be etched by this type of laser. Also is harmful as the reflective surface may cause the laser to be reflected back up to the head, damaging it. If someone claims to be etching metal using this type of laser then they are etching a metal with a plastic coating, anodized surface, or some other etchable surface on top.

Known good materials

These materials are known to be ok for use with the laser cutter. The speed and power of the laser cutter will need to be set appropriately for the material and thickness in use. Below is a table showing the suggested settings when cutting or etching them.

Good Materials
Material Engraving Cutting Scoring Notes
Speed (mm/s) Power Speed (mm/s) Power Kerf Width Speed Power
Acrylic (1mm) 400 5 30 20 0.15mm The plastic has a tendency to stick back onto itself a little after cutting because it's so thin, so you may have to pop your pieces out
Acrylic (2mm) 400 5 30 20 0.15mm
Acrylic (3mm) 400 5 20 55 0.15mm Power setting 4 and 5 have little visible difference except some minor lightening at the beginnings of cuts at power 4. Power 3.5 produces very light engraving, almost non-existent, with no engraving at the beginnings of cuts. Above power 5, little difference is visible, but powdery soot becomes more prevalent. Power 5 seems to be the best setting to produce frosted effects.
Acrylic (4.76mm \ 3/16 inch) 400 5 16 55

Acrylic (6.35mm) (1/4") 400 5 8 55 0.15mm
Acrylic (12.5mm) 400 5 3 55 0.15mm Focal length is 4mm
Acrylic (18mm) 400 5 6 55 0.15mm Focal length is 4mm; cuts require three passes, don't move piece between passes
Balsawood (3.2mm) 400 5 50 10 Engraving balsa produces little differences in power above 5, and below 3.5 or so, there's no engraving at all.
Balsawood (1.6mm) 400 5 50 7 Engraving balsa produces little differences in power above 5, and below 3.5 or so, there's no engraving at all.
Bamboo (3/32" nominal, 2.5mm actual) 400 3-20 55 45 Engraving power 3% produces visible, but very light, marking w/ no depth, 20% produces darker marking but w/ significant depth
Basswood (1.5mm) 400 5-20 50 15 Engraving above power 20 seems to produce no difference in color, only depth, see reference piece in toolbox.
Basswood (6.5mm) 400 5-20 20 55 Engraving above power 20 seems to produce no difference in color, only depth, see reference piece in toolbox.

Birch (0.9mm) 400 5-15 40 20 Engraving is very finicky; 4 is the absolute lowest the machine will engrave at, 15 is high enough to cause serious charring on birch. The 5-15 range is best. See the test engraving for what the 5, 10, and 15 settings produce.
Birch (4.8mm) 400 5-15 35 55 Engraving is very finicky; 4 is the absolute lowest the machine will engrave at, 15 is high enough to cause serious charring on birch. The 5-15 range is best. See the test engraving for what the 5, 10, and 15 settings produce.
Birch (1/4 inch plywood from Discount Builders Supply) 15 55 The actual thickness of this stuff varies a lot throughout the sheet, plus there are knots in the wood that are harder to cut through. These settings should work though.
Birch (1/2 in) 5 55 0.2mm
Cardboard (4mm) 50 15 50 5 Minimum line separation at 50/15 ~ 1/2mm
Cardboard (6.5mm, double corrugated) 50 40
Cardboard (6.5mm, double corrugated)
Cardboard (6.5mm, double corrugated)
Cardstock (white, 80lb) 140 6 140 4 The higher speed reduces the amount of browning on the edges.
Cardstock (white, 138lb / 224GSM, Canson brand drawing paper) 55 5 140 3 speed 140 power 3 for a lighter score, speed 200 power 4 for a heavier score.
Cardstock (Fabriano brand, 160 GSM, 40% cotton) 100 5 140 3 The color tested for safety was Tiziano 02 Crema
Chipboard (~6mm) 30 25
Cork (nominal 1/4") 400 2-3 30 40

Corrugated Plastic (white, 3.7mm) 10 15 50 5
Corrugated Plastic (yellow, 4.1mm) 10 15 50 7
Delrin (nominal 3/8", actual 9.6mm) 5 50
Denim 200 4 50 7 engraving numbers might produce very thin fabric, might fall apart in the wash
Douglas Fir (15mm) 400 3-25 3 80 power differences are mostly differences in depth not color; engraving produces different depths over the growth rings due to wood density changes = rippled surface
Fabric - 1000D Cordura Nylon 100 20 crisp heat sealed edges
Fabric - Alpha Broder Style 88127 (7.4oz, 96% polyester, 4% spandex) 100 15
Fabric - ~0.2mm polyester/cotton blend 100 10 crisp heat sealed edges
Fabric - ~0.6mm cotton?/spandex blend 200 20 better edges
Fabric - 100% poly burlap from Amazon ( 100 7
Fabric - 100% poly gabardine from Fabric Outlet 100 7 You do have to pull the cut fabric apart (it's not a clean cut), but it rips at the cut cleanly.
Fabric - 100% rayon crepe from Fabric Outlet 100 7 You do have to pull the cut fabric apart (it's not a clean cut), but it rips at the cut cleanly. I think this is just a property of the fabric melting back together after being cut. I tried increasing the power and it didn't result in a cleaner cut.
Glassine (cellulose paper) 55 5 100 2
HDPE (0.8mm, 1/32 inch sheet from TAP Plastics) 20 30 creates a beveled edge and a slight under-hanging lip
MDF (5/8") 5 55-75 400 5-15 Cutting doesn't go all the way through necessarily, it gets spotty at this thickness. The power range was tested and produced similar results throughout, but YMMV.
Notebook from Muji: Recycled paper notebook beige A5 plain, orange spine 50 5-35 5 will just score through the cover 10-15 will cut through, and 35 will cut through a few pages. Any higher and there's a fire hazard. Be sure to tape or weigh the book down flat or else it's more flamey.
Paper (printer paper) 55 5
Plywood w/ reddish tinge (2.6mm) 35 30
Plywood (3mm) 400 5-55 35 50 see reference in toolbox for engraving
Plywood (1/8 inch, square foot for $2.99 from Discount Builders Supply) 50 55
Plywood (5.6mm) 400 5-55 15 55 see reference in toolbox for engraving
Plywood (9.5mm) 400 5-55 7 55 see reference in toolbox for engraving
Plywood (12mm) 400 5-55 5 55 requires overcutting beginning/end; see reference in toolbox for engraving
Plywood (18mm, nominal 3/4") 400 5-55 3 85 speed and power is imprecise (3/85 cuts through fine sometimes, while 2/85 doesn't always cut through fine)
Polypropylene (0.5mm) 50 10 Ruth has found that 50 speed 20 power gives a cleaner cut for the 24x45 inch sheets from TAP plastics.
Polypropylene (1/4in) 4 55
Redwood (20mm) 100-400 55 3 55 5mm/s gets you almost there, so you could probably go over it a second time and it would work instead. Or if you sand it down a bit, that would probably work. I've only tried engraving on max power. You won't get a consistent depth, and it will vary depending on the grain of the wood. Looks col, but just be aware.
Red Oak (0.25 inch) 400 23 12 55 Engraving power 23 gives a dark engrave on a .5-1 mm line thickness. 12-18 gave a lighter engrave. When cutting a knot in the wood, you'll have to use a lower speed, 9-10 will probably work. This wood was high quality scroll wood with almost no knots.
Transparency Sheets 400 6 Only chlorine and speed/power tested a mystery brand from Switzerland that Henner bought; other brands may require tests again

The Laser Gallery contains some past projects and cutting tests.

Sourcing Material

In general, you can get stuff form Amazon, but you have to wait for shipping.

For plastics: Tap Plastics is nearby Noisebridge, but is expensive, eplastics is cheaper but you need to wait for shipping, and Mr. Plastics is cheapest but is in San Leandro.

For woods: Discount Builder Supply is nearby.


Help! All the menu options turned to gibberish!

The RDWorks software can be buggy. Go to the top menu, the right-most or or 2nd-right-most tab will have a Language option. Select English. When that happens, the bed size settings might also have changed. Double check Config -> Document Settings (?). The proper settings are 1300mm × 900mm. (TODO: need to double check the exact menu labels, doing this from memory at the moment)


Apparently DXFs exported from Solidworks (at least v 2017) break when directly imported into RDWorks. The workaround is to import the DXF into Inkscape and re-export it from there.