Neil gives brief overview of available cutting tools at the MIT lab, including water jet, hot wire, wire EDM among others. Fab labs focus on the vinyl cutter and the laser cutter.
Vinyl cutter is the least appreciated tool in the fab lab. Typically used to make signs, cut thick paper, screen printing, flexible circuits, stencils and antennas.
Adhesive tape is used to lift patterns off vinyl roll. Carpet tape also works
Transfer adhesive is used to transfer adhesive to material (like paper) that isn't sticky. Also serves as a backing when running through the machine.
Cast Epoxy Film very durable, you can solder on it
Copper sheet (typically used for EFI Interference), works for flexible circuit board
Vinyl $59/roll
Copper $278/roll
Force and Speed settings vary with the material.
Vinyl 45 gm, copper 60-70 gm, epoxy 80-90 gm approximately
Roland ships the unit so that it will ignore the force setting sent by the computer. Neil will post a link to show how to circumvent this.
Make sure the blade is adjusted correctly. Just protruding enough to cut the material, not through the backing.
Roller support allows for easy dispensing of vinyl roll. Do not use for making detailed work, as the tug on the roll may have an effect on the dimensions. The vinyl cutter has a resolution of a few thousandths of an inch, whereas the mini mill is a few tenths of a mil (a few microns).
It is also a pen plotter, and has an optical scanner to trace outlines. You may cut anything with it that you can with an exacto knife.
You remove the bits you don't want by weeding. Often, the adhesives are pressure set. Use a pair of tweesers, and pull material off by shearing, not lifting. If done properly, the stuff will slide off and separate with the right touch
used for marking and engraving
half tone screen printing
especially useful for press fit construction
With the ECT-44 cardboard we are using, try to get the mating surfaces within 5 thousands of an inch so that they stick. Try to design in a spring as the joint spacing is optimized.
Lasers – we have a 50W CO2 laser with approximately 10 micron beam. Cuts by burning, melting, evaporationg, and ablation. Two sources of airflow, 1)exhaust and 2) air assist. Works well on birch and acrylic, and cardboard. NO UNKNOWN PLASTIC, ESPECIALLY NOT PVC (CAN RUIN MACHINE). THIS IS A CLASS ONE LASER, IT WILL START A FIRE IN THE LAB IF LEFT UNATTENDED. MOST LAB FIRES RESULT FROM THE IMPROPER USE OF THIS MACHINE.
Don't even try to cut polycarbonate or lexan, you need hundreds of KW's to do that.
Don't cut shiny material – cover with paper, or smoke it.
The laser will both vector cut and raster cut. AS220 has printer drivers written in python that work very well for the cutting machines
We will use the fab modules for our work, now available with an exciting new GUI front end. Still same old reliable modules on the back end
In addition to Inkscape, the program Scribus is also free and has nice boolean tools. Blender is very nice as well, for those who can scale the “brick wall” - it is not a fast program to learn, but it does very nice work
Try to keep the growth rate at or near 1Mb per week per student – put videos and such on video sharing plate so as not to overload the archive