NI appears to be interested in helping me with the project. They are going to try to find a cRIO system that I can use to control the system. If this happens, it will be totally cool. The FPGA side of the RIO will run the motor control loop really, really fast and keep track of the cart and pendulum positions. The RT side of the RIO will run the logic for inverting the pendulum and send the setpoints over to the FPGA side.
Checked around for cable carriers and prices to keep the cables from flopping around. It is a difficult problem to solve, because the space between the cart and the shelf where the cable carrier has to fit is about 0.7 inches, and the cable carrier has to support two feet of cable. Right now the best solution is from Kabel Schlepp. They are the only ones that can support the full two feet of cable. Their price is in the middle (Gortrac lowest, Igus highest). The only problem is the minimum order of $50, which I am hoping they will waive. Interestingly, Igus does not have a minimum order, and Gortrac has a minimum of $100. The cheaper the carrier, the higher the minimum order. I guess they have to make their money somehow. This is the last thing I will need, so I will wait until everything else is done to see what will work.
The gears from McMaster came in today. I love ordering stuff and getting it the next day!! The rack gear is pretty big and kind of heavy, but it looks like it will work well. The spur gears are really thick and very heavy! They are going to add way too much mass to the cart. Maybe they can be machined down or something. There is way more metal than I need there.