Motor control boards
We are moving away from the allegra A3985 chip and to the A4985 as we go from the MTM lead screw machine to the timing belt machine. Originally we were controlling the snap machines with g-code, which was interpreted by GRBL running on an arduino. It is documented at http://mtm.cba.mit.edu/machines/mtm_snap-lock/build/electronics.html, where you can download schematics for an arduino shield.
Here we are exploring a more modular approach, where each motor controller has its own breakout board.
Download the circuits and the pngs for milling here.