Laser Class

From Fat Cat Fab Lab

See Laser Cutting for general information on the laser cutter. This page contains notes from the class that is an introduction to using our laser cutter.

Registration & Schedule

  • See our Meetup events page for scheduled classes here: Scheduled Classes
  • Classes are every other Tuesday, 6-9pm.
  • Class is $50 for members and $75 for non-members.
  • Once certified, you're certified for life!
  • This is the quiz, where all answers are covered in the class.

Instructors

Laser Class: Basic Usage & Safety is taught by our wonderful volunteer instructors Harrison Friedes (@Harrison Friedes), Gaurav Pandey (@gaurav), and Shy Ruparel (@Shy)!

Choosing your materials

  1. Must be in the list of approved materials
    1. To add materials to the list, slack #laser. If not a member, email [email protected]
    2. Reflective material can cause damage to the lens & laser. Either cover it with painters tape or flip it over if there is an opaque side.
  2. Must be raw material (not painted etc)
  3. Must be from a reputable source

Workflow

Instructional video here: Fat Cat Fab Lab's Trotec Speedy 300 Laser Cutter Workflow Instructions

Adobe Illustrator

  • Make design in Adobe illustrator as a vector file
  • Settings: units should be millimeters, everything else default should be good. Color mode rgb, raster effects high.
  • Top bar > Document Setup > Edit Art Boards > drag around size of the art area or set width and height explicitly at the top (mm)
  • For the lines that you want to cut, set the stroke to 0.001 mm so the cutter only has to make one pass. You probably want the fill of the shape you’re cutting to be None.

We have color conventions at this point, even though to some extent you can customize them later on in Job Control

  • Pure red (255, 0, 0) = cut
  • Pure black (0, 0, 0) = engrave

Print to Job control

  • file > print > Adobe print dialog box
  • Deselect auto rotate. Placement top left (move matrix)
  • Change the size of our document to the size of your drawing area. It’s probably set to whatever it was last time.
  • Setup (bottom left of Adobe print dialog box) > Windows print dialog > Preferences > job control printing preferences > top right change width and height
  • You can also flip your print horizontally here (i.e. if you’re flipping it over to cut on the opaque side)
  • Hit JC to confirm
  • Hit print in Adobe illustrator and your job will get sent to Job Control (another piece of software)

Job Control

  • Job Control runs in a program called VNC, kind of like a remote desktop onto the laptop next to the laser cutter. VNC should be running on your computer already, but if not you can run the executable file jobcontrol.vnc
  • Right click remove job (if there is an existing job) to move it back to the job queue on the right. Delete job removes it from the queue entirely
  • Find your job in the job queue on the right side. If you don’t see it, try these steps:
  1. Hit show all
  2. Print it again
  3. Reboot the computer next to the laser printer
  4. If none of these steps work, ask for help
  • Drag your job onto the representation of the print board in JC
  • Eyeball at top shows you a preview of the job

Material settings

New users should create their own folders of material settings. In Job Control, go to Settings > Material template setup > Bottom left, scroll down. Right click > create group > first name last initial. You can copy settings from another person’s folder This is where you can customize how the colors in your file translate to the laser cutter.

Columns left to right:

  • Power (1-100%): Don’t go over 90%. It's a percentage of laser power (80W max).
  • Speed: cutting is slower
  • Points per inch: related to power, how many times per second the laser is turning on and off
  • Passes: number of times the laser goes around the path or engraves the shape
  • Air assist: leave it on. Machine removes smoke and debris from the lens with compressed air.

Running the laser cutter

Pre-Cut Checks

It’s a good idea to regularly clean the lens, especially if it looks smudged or dirty. The lens being dirty can cause them to crack (and therefore need to be replaced… $$$!!!). Use a few drops of the pink lens cleaner in the yellow pack near the laser cutter and dab it off with the microfiber paper.

  • In order to print, you need to make sure the print bed is at the right height relative to the tip of the cutter.
  • Move the print bed so that your material is ~1.5” below the tip (if your material is bumpy then use the highest point for these steps)
  • Hang the calibrator off of the little ledge on the cutter tip (see picture)
How the calibrator hangs off the laser to adjust height
  • Raise the bed just until it knocks the calibrator off the ledge
  • Be careful not to cut material too close to the laser cutter. This can also cause the lens to crack

General checks

Four signs to look out for when you are starting the laser machine:

  1. You can hear the fan sound
  2. There is no thumping noise. That means a filter might be blocked
  3. Smoke created by your job should not be sitting in the cabinet. Immediately stop the job if that happens
  4. Smoke should be getting quickly sucked into the back of the cabinet, not moving slowly

If you see any of those four signs, do these three things:

  1. Stop the job by lifting the lid (the fastest way to stop the job)
  2. Hit stop button on bottom right of Job Control
  3. Post a physical note on the machine with the problem. Members post in #laser in slack, non-members can email [email protected]

Flame Ups

Sometimes flame ups can also happen. This happens when you’re cutting an organic material like wood or cloth and it catches on fire. If the fire is small, use the oven mitts nearby the laser cutter to smother the fire with your hands. The last resort is to use the fire extinguisher, since that can ruin the laser cutter.

To prevent flame up, you can increase speed and decrease power. You may need to correspondingly increase the number of passes to make sure your material gets cut through.