Full Spectrum Laser
There are a wide range of materials that the Laser Cutter can cut, etch or mark - but some simply don't work (eg metals) and some are extremely hazardous to either humans or the machine itself (eg PVC and ABS). It is therefore imperative that you check these lists before attempting to cut materials that you have not worked with before.
It is not always obvious which materials will work. For example, Polycarbonate/Lexan produces flames and lethal chlorine gas which will rapidly corrode the machine into uselessness, and is extremely hazardous to the health of people nearby. Yet Acrylic - which looks, smells, feels and tastes just like Lexan, cuts smoothly and cleanly and is one of the best materials to use with the laser! So check and double-check what you're cutting.
NEVER CUT THESE MATERIALS
WARNING: Because many plastics are dangerous to cut, it is important to know what kind you are planning to use. Make has a How-To for identifying unknown plastics with a simple process.
|PVC (Poly Vinyl Chloride)/vinyl/pleather/artificial leather||Emits pure chlorine gas when cut!||Don't ever cut this material as it will ruin the optics, cause the metal of the machine to corrode, and ruin the motion control system.|
|Thick ( >1mm ) Polycarbonate/Lexan||Cut very poorly, discolor, catch fire||Polycarbonate is often found as flat, sheet material. The window of the laser cutter is made of Polycarbonate because polycarbonate strongly absorbs infrared radiation! This is the frequency of light the laser cutter uses to cut materials, so it is very ineffective at cutting polycarbonate. Polycarbonate is a poor choice for laser cutting.|
|ABS||Emits cyanide gas and tends to melt||ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching on fire and leaving behind melted gooey deposits on the vector cutting grid. It also does not engrave well (again, tends to melt).|
|HDPE/milk bottle plastic||Catches fire and melts||It melts. It gets gooey. Don't use it.|
|PolyStyrene Foam||Catches fire||It catches fire, it melts, and only thin pieces cut. This is the #1 material that causes laser fires!!! (Commonly known as Foam Core board)|
|PolyPropylene Foam||Catches fire||Like PolyStyrene, it melts, catches fire, and the melted drops continue to burn and turn into rock-hard drips and pebbles.|
|Fiberglass||Emits fumes||It's a mix of two materials that cant' be cut. Glass (etch, no cut) and epoxy resin (fumes)|
|Coated Carbon Fiber||Emits noxious fumes||A mix of two materials. Thin carbon fiber mat can be cut, with some fraying - but not when coated.|
Laser Cutter Operating Instructions
Turning ON the Laser:
- Using the switches located by the door just inside the Furnace Room, turn on the Power Vent and the light in that room. Keep the door closed.
- Boot up the Laser’s laptop computer.
- Check to make sure the Ethernet cable is connecting the laptop to the Laser Cutter.
- Important!! Switch on the power strip located in the left rear corner of the bench. This turns on the air compressor and the cooling water pump. DO NOT FORGET TO DO THIS STEP!!
- Confirm that you can hear the sound of the air compressor and that you can feel the vibration of the water pump on the water bucket.
- Twist the Big Red Button in the direction of its arrows to power up the laser.
- Launch the RetinaEngrave software and look for “Connection” and an IP Address at the bottom of its screen.
- Paper Size should be set to “FSL Hobby Series Gen5 20 x 12”
- Click “No” for “Ignore Raster and Load Vector”.
- Send the Laser Cutter to its home position. This must be done before cutting your first piece after powering up the Laser Cutter.
Focusing the Laser:
- Place your material in the Laser Cutter.
- Use the Arrow Buttons on the Laser Cutter to position the lens head somewhere over the material.
- Place the Focusing Billet (the metal cylinder marked with the number “2”) between the lens head and the material.
- Loosen the thumb screw on the front of the lens head and let it drop down to rest squarely on top of the Focusing Billet.
- Tighten the thumbscrew while being careful that the lens head remains squarely on the Focusing Billet.
Turning OFF the Laser Cutter:
- Hit the Big Red Button on the top of the Laser Cutter.
- Switch off the power strip located at the left rear corner of the bench.
- Turn off the laptop.
- Turn off the Power Vent and light in the Furnace Room.
- Close the Laser Cutter’s lid.
Some Handy Keyboard Shortcuts:
- “h” = Home Position
- “j” = Causes the spotting laser to draw a box around the extents of your piece. Use this to check the position of where the cut will take place on your stock material.
- “g” = Means Go Make the Cut! First make sure the lid is closed or nothing will happen.
- If you’re cutting out shapes then your drawing file must be made up of continuous, polylines that form closed shapes.
- If your shape contains cutouts enclosed by an outer shape then you should assign a line-color to the lines forming the inner shapes that’s different from the line-color of the outer shape. That way you can have the laser cut those inner shapes first before it cuts the outer most shape that would release the piece from the stock material. It’s generally best to cut from the innermost shape to the outermost shape.
- If cutting through the material it’s best to set the Power Level to 100%, make a Single Pass and lower the Cutting Speed to just the point at which the laser pokes through the material but no slower. This will require experimenting with the cutting speed on your particular material and thickness.
- Making Boxes: If you want to make a 3d box that will fit together there is a handy Perl script written by another maker from NYCResistor. Code is here.