Introduction to Using the Trotec Laser Cutter/Engraver
We have access to a Trotec Speedy 300 Laser Cutter/Engraver (pictured above) in Olsen Hall. It uses a precision positioning system and high power laser to cut and engrave two dimensional designs in nonmetallic materials, such as cardboard and acrylic. Because of the time it takes to master the laser cutter/engraver, Bill will do all of the cutting and engraving for you (if you want to watch him do it and learn more, go with Bill and ask questions!). All you need to do is learn how to create a design that can be properly cut and engraved, and ask Bill to fabricate it for you. You should run your ideas by Bill first and get some feedback! You will always be required to later cut/engrave a prototype out of cardboard before cutting into your expensive final material!
The computer interfaces with the laser cutter just like a printer. You pass it an image file, but instead of putting ink on paper based on colors in your image files, it adjusts laser power based on the colors in your image file and cuts or engraves accordingly. It has two general modes: cutting, which cuts quickly along lines, and dithering, which rapidly moves back and forth over a designated area for engraving.
For simple designs, Microsoft Word 2003 AutoShapes drawings work well with the laser software. Here are the general rules for drawing a design for the laser cutter:
0. Safety:
- Laser Safety: Read all of the safety warnings provided by Trotec. When working with any laser, you must take preventive steps to prevent direct exposure to the eyes. With this system, if it can cut through 1/2" acrylic plastic, it will do the same to your hand, so operate the system with all the safety features enabled (e.g., cover is closed). Where protective eyewear recommended by the manufacturer.
- Material Safety: The laser "burns" materials to engrave or cut. The gases that are released as part of the burning process may be toxic! To prevent this from happening, check the MSDS, warning labels, etc. before you cut any material. Do not use the laser to cut or engrave any material that contain chlorine (e.g., don't cut PVC = polyvinyl chloride). Becareful with "foam" products--they may release dangerous gases if burned.
1. Cutting:
The laser cutter/engraver will cut any thin red lines it encounters in the image file. To set a line or shape to the proper settings...
- Right click on it and select “Format Autoshape”
- Under the “Colors and Lines” tab, set the line width to “0 pt” and set the color to true red
Note that you must define a new true red line color (don't trust the red you see in the color palette). Follow these steps to define a "true red" line color:
- Select “More Colors…” in the colors menu and on the “Custom Colors” tab
- Modify the red-green-blue (RGB) settings as follows...
- set red to 255
- set blue to 0
- set green to 0
2. Engraving:
Anything you want engraved, leave black. For example, you can add text in black, drawings, photos, etc. Use your imagination!!
3. Example
- Here's an example of a plaque I made for a friend - it is made of 3 layers of 1/4" acrylic--the front and back are clear acrylic, and the center layer is 5 pieces of colored acrylics (various bright colors). Note that I used Microsoft Word's drawing tools to do everything (the grid is a nice feature).
4. Pactice Assigment: Design & Cut Your Own Keychain!!
5. What types & sizes of materials can be engraved?
The Trotec laser is designed to cut or engrave a variety of materials in two dimensions (i.e., surface of material must fit in the bed and must be orthogonal to the laser beam). The bed moves up and down to accommodate "tall" materials. For example, you could put a large ABS project box onto the bed, and cut holes and engrave labels onto the top of the box. The bed size for materials is 17" x 28".
The laser cutter/engraver will work with many materials (note safety information above). For example...
- Cardboard, manila paper, and regular paper are all great for prototyping before you use your expensive material!
- Acrylic plastic sheets - most of the plastic cutting you see in the lab is acrylic. Acrylic is nice to work with when using the laster cutter, but but can break, fracture, or shatter when cutting or drilling with "normal" tools. We have cement to "weld" acrylic pieces together. Clear acrylic is cheapest, colored is more expensive, and neon colors are most expensive. If you are artistic, you can paint the back side of the acrylic for a nice look (paint can scrape off if you don't protect it.
- PET-G plastic sheets look like acrylic, but are much easier to cut and drill with "normal" tools (won't break, fracture, or shatter like acrylic). It is more flexible than acrylic (but still rigid and strong), and is nearly impossible to break. It scratches more easily than acrylic, but you can use a heat gun to "melt away" the scratches. You may also use heat and re-form the plastic.
- Thin (1/4") plywood or medium density fiberboard (MDF) - a bit smoky when cutting (and leaves black burn marks on wood), but you can get nice, clean cuts
- Toast - engrave an image of Jesus on a piece of toast and sell it on eBay as a "miracle"???
- And many other materials, just test first on a small piece!
- Do not try to cut or engrave these materials...
- PVC or other materials that contain chlorine or release noxious gases when burned (see safety warning above)
- metal (laser is reflected, cannot penetrate material)
- metal plated materials (laser is reflected, cannot penetrate material)
- Lexan (won't cut at all)
6. Here are some sources for plastic material:
- US Plastic - Acrylic is heavy so expect high shipping cost
- Patriot Plastics - located in Woburn, so we can pick up materials to avoid shipping costs & delays. May only have clear acrylic (no colors).
- WW Grainger sells lots of industrial items, including several types of plastic (and I think we get a UML discount on the prices)
