Using the Laser Cutter

(soon to have more pictures)

• Never leave the laser cutter unattended.
  Your stock might ignite, and an unchecked fire in the laser cutter could be both dangerous and costly.
  
  
• Never cut PVC or chlorinated plastic.
  You should always know what material you are cutting, and chlorinated plastics should be avoided because they release chlorine gas when cut.
  
  
• Do not try to cut metal in the laser cutter.
  This is probably intuitive to everyone in the class.
  
  
• Check that the lens is clean before using the laser cutter.
  As the laser cutter is used, vaporized material will collect on the lens. This material must be cleaned from the lens before further use or it will get cooked into the lens and cause the lens to crack. New lenses are not cheap.
  
  To check the lens, unscrew the three screws (careful not to drop them), and pull out the lens and mirror. If they appear clean, return them. If not, clean them with a cotton swab and the cleaning material found above the computer. If you lose one screw, you can still run the laser cutter. If you drop two screws, you cannot run the laser cutter.
  
  
• Know how to stop the machine and what to do in the case of a fire.
  To turn off the laser, simply open the lid of the laser cutter. If you want to keep the lid closed, you can press and hold the pause button.
  
  If there is a fire:
  • Open lid to stop the laser.
  • Put an acrylic sheet over the burning material to smother the fire (always keep a sheet of acrylic handy when cutting for this reason).
  • If you can reach it, push up the blast gate to stop air flow.
  • Use the fire extinguisher (it is located next to the door opposite the laser cutter).
  • If you cannot put out the fire or feel that you are in danger, call the campus police (100 from the phones in the lab or 617-253-1212 from an outside line).
  
  
• If the lab phone rings, answer it. It is probably John DiFrancesco watching you via the lab surveillance camera and figuring you could use some help. You can also e-mail him with any questions (difran@media.mit.edu).

• Using the laser cutter will at first seem easier than using the other cutting tools because the laser cutter is run like a printer from CorelDraw. Unlike the waterjet cutter, the laser cutter does not cut to the side of a line--it cuts right down the line. The cut will usually be 0.010 inches thick, although it can be thicker under unusual cutting circumstances.
  
  
• The first thing you do when you start a new document in CorelDraw is to set the page size to the size of the laser cutter. In page setup, the laser cutter bed is labelled "LC."
  
  
• As you make your drawing, you can use eight different colors which can each be turned on or off or changed from vector mode (cutting all the way through) to raster mode (etching) later on. When you change the color of part of your drawing, go to the palette to find these eight colors.
  
  
• When you print your drawing to the laser cutter, you will have go into properties to set the printer for the material you are using. Suggested values can be found on the lab computer. It is in properties that you can turn certain colors on or off or choose vector or raster mode (or, more rarely, a combination mode). Make sure that Gas Assist is set to "High" or "Low."
  
  

• To turn on the laser cutter, flip the orange switch on the right side of the laser cutter. It is low and towards the back.
  
  
• You must focus the lens to each new material. This must be done through the somewhat non-intuitive menu display on the laser cutter. The x-in-a-circle button takes you up one menu level or answers "no." The check button selects a menu item or answers "yes." You must go up to the level where the laser cutter's bed height can be adjusted. Select that option, and the up and down arrows beside the display will move the bed up and down. To focus the laser, use the focusing tool for the two-inch lens. You can move the laser our with the x and y arrow keys. Place the tool under and to the side of the laser so that it into the large rectangular part of the laser. Lower the laser until it meets the tool.
  
  
• Once you print your file to the laser cutter, use the left and right arrows (the ones that look like forward and backwards on a CD player) to make sure that your print job is selected. Note: the cutter will not necessarilly default to the most recent job.
  
  
• You will probably want to run a test run before you actually start cutting. To do this, simply hit the green print button while the lid is still open. A red dot will trace the laser's path. To make the actual cut, press the green button when the lid is closed. A little bit of fire is natural for the laser cutter, but keep an eye on your job to make sure things don't get out of hand.
  
  
• Tip: if you have selected the right print job and the laser cutter is still cutting a previous design, you might want to go to "Print Preview" in CorelDraw and change the box marked "Custom" to "As in Document."
  
  
• Tip: if you are using really big stock, you can open the front of the laser cutter to put it in. Make sure to lower the bed so that you don't hit the laser.
  
  
• Remember to wait at least a minute after the job is done before opening the laser cutter to let the fumes and smoke clear out. Also remember to clean up and turn off the laser cutter if no one else is going to be using it.