Laser Cutter Instructions and Workflow

Introduction

Our laser cutter is an Epilog Mini 24 30-watt system with a bed 24” by 12” (610 x 305 mm) and which can cut through materials up to 0.25” (6.35 mm) thick (Thicker materials can be cut, but may require multiple passes). Material must lie flat on the bed, as warped or curved materials will cause the beam to be out of focus when it cuts or engraves. Important: only certain materials can be cut, but of special note is NO PVC OR VINYL as those materials will release toxic chlorine gas (think World War I) and damage the machine. If you have questions about the material use the “hot wire” test (see below). Also beware of fabrics, as certain dyes can also release toxic vapors.

The laser has two modes: raster and vector. Raster (aka: “multi-pass cut”) etches an image via multiple passes over an area, whereas vector (aka “single-pass cut”) makes a single pass over the material, cutting where the reference image has indicated. The host computer sees the laser cutter as just a regular printer and thus it can print from any program. We suggest you print from a vector-capable program such as Adobe Illustrator, Inkscape, Corel Draw, AutoCAD, etc.

1. File Prep

a. All files to use (for cutting or engraving) should be vector (.ai, .svg, .eps, .pdf).

b. “Hairlines” (0.001”/0.025 mm/0.1pt) are vector cuts. Anything larger is a raster engraving.

c. If you are importing an image, make sure that any fonts that would not be normally found on a Windows machine (assuming you’re printing from the lab machine) have been rasterized.

Configuring Laser Settings

• When you are satisfied with your image, print the image from the vector application.
• In the Windows “Print” dialog box
• Printer should be Epilog Engraver Win32.
• Click “Setup”.
• Click “Preferences”.
• Choose the job type: “Raster”, “Vector”, or “Combined” based on if you are cutting, etching, or doing both. If you have a Raster or Combined job, set the resolution appropriately, but generally there’s no need to go above 600dpi.
• Do not enable Auto Focus.
• Set the piece size accordingly, or just set to 24” by 12” and set the art board within the vector application to 24” by 12” and then position the cutting/engraving image within the art board in).
• Raster settings (for engraving) are applied to strokes within the image that’s over a hairline (as defined above), while vector settings (for cutting) are applied to hairlines. If you have a combo image, you’ll have to set both. These settings depend on the material properties and thickness and there is a handy reference chart on the wall with commonly used materials.
• Set “Engrave Direction” to “Bottom Up” as cutting in that manner works better with the airflow through the machine.
• Dithering settings can usually be left alone, except in the cases of specialized images.
• “Vector Sorting”, which determines which cuts are made first should be checked. Generally optimize is fine.
• Frequency Automatic can generally be left alone.
• Click OK.
• Click Print.
• Set the proper orientation, rotation, placement, etc.
• Do not click “Print” until the laser is on.

Cutting and Engraving with the Laser

• Confirm the ventilation system is running (the orange fan in the garage on the wall). An easy way to check is just to touch the large exhaust tube, as it will be vibrating if the exhaust fan is on.
• Confirm that the second exhaust fan is on (this fan is in the ceiling in the garage. You may need a may need a pole to turn on the light switch on the ceiling.)
• Turn on the power switch on left rear of machine. The initialization process will run.
• Once it says “Job: “ on the cutter’s display, you can click “Print” on the controller computer.
• The file name of your image will show up on the cutter’s display.
• Reset home: place your material in top left corner (ideally) then press the “Pointer” button on the cutter’s front panel to turn on the laser pointer. Press the “Disable X/Y” button. The display will say “X/Y Off? “Go/Stop”, press the “Go” button to confirm and the display will read “X/Y Disabled”. You may now manually move the laser head around. DO NOT TOUCH THE LENSES OR MIRRORS. Move the laser pointer to the starting point (top left most corner, usually).
• Press the “Set Home” button.
• Press the “Reset” button.
• Optional: With the cutter lid open, press “Go” and watch a test cut (non-destructive) to confirm proper operation. When satisfied, press “Stop” and then press “Reset”.
• Close the cutter lid.
• Turn on the air assist (blue knob inline with tubing to the right of the cutter). The air compressor in the garage needs to be on and regulator positioned to 20-30PSI (no more). Air assist will audibly hiss.
• You’re ready to cut or engrave. Press “Go” and watch the light show.

Cleaning/Finishing Up

• Turn off the air assist when done.
• Shut down all apps on the lab computer and log off (be sure to take any files you may have changed).
• Turn off the cutter (switch on the rear left).
• Turn off the exhaust and air assist compressor systems in the garage. There are 2 fans, the one with the orange housing that sucks air out of the cutter through the duct (unplug it) and the big vent on the ceiling that the duct leads to (there's a switch on the ceiling, use something long).
• Clean the single lens and the two mirrors. Grab a Q-tip from above the laser cutter and the bottle of lens cleaner. Saturate the tip of the Q-Tip with 3-4 drops of the lens cleaner fluid. Using a circular motion clean off the surfaces of the mirrors and lenses with the moistened Q-Tip. Wipe up the moisture with the other end of the qtip. Dispose of the Q-Tip when done.
• Open the front panel on the cutter, flip out the levers on the black tray, slide the tray out of the cutter, and empty it into the garbage.
• Return the tray to the cutter, flip the levers back into the locked position, close the door and you’re done.

HAPPY LAZZORING!

Hot wire test for chlorine

Chlorine is a very dangerous gas used in the creation of many plastics (e.g. PVC). These plastics are safe until heated, whereupon they release toxic chlorine gas which is highly poisonous to humans and will severely damage the machine. The laser cutter will easily heat plastics enough to release the gas, so to avoid a rather nasty situation, use the following technique to test an unknown plastic for the presence of chlorine. This is formally known as the Beilstein test.

1. Heat some copper wire until red-hot (do this for a while to remove any PVC that may be stuck to the wire from the coating).
2. Apply the red-hot copper wire to plastic so that it melts a little onto it.
3. Heat copper wire until red-hot again.
4. A green flame means that the plastic contains chlorine so do not use it.