I connected the heat spreader to the M- bus bar with JB weld (with some space between them too) and connected the mosfet/diode clamps. Those clamps push with like 25 or 30 pounds I think. They are designed just for these specific TO-247 type of packages.
I finally found a good way to cut plexiglass. We bought an attachment to the dremel. I also bought a small piece of Lexan to finish the box, and it is way easier to work with! I might be able to trim down the size of the box some. Version 2 can be quite a bit smaller. This box is just a temporary thing to hold everything. I should finish the box this weekend.
I'm almost done with the control board. I also have a nice new big breadboard! Plenty of room!
motor_control: I haven't uploaded the software yet because it is undergoing dramatic changes.