[Cothron Theiss]

At the beginning of the season, my team considered a half-track drivetrain that used a thick rubber-backed timing belt as the tread for the track portion. We printed off an early version of the wheel/pulley out of Ultem 9085 that interfaced with the KOP AndyMark sprockets. Just for testing, we threw it on a CIM and direct drove it to see how it was balanced and how it handled at high speeds, then we put it on a dead axle and hung 100 pounds from the pulley to see how it held. It looked good from those tests, but we soon decided we didn't want to print our wheels, especially since the teeth of the wheel would be taking a lot of shock loading when we went over defenses.

I would echo what several people have already mentioned and voice my own interest in making custom shooter wheels. The urethane casting sounds like a really amazing thing to do, because it seems practical and very educational. Also, for the purposes of involving other teachers, I think you have more opportunities to delve into multiple subjects more easily with some type of shooter wheel than just a drive wheel.