A little bit OT, but the friction drive on Daniel Kerrisons The Aggressor works pretty well. It spins the flywheel up fairly quick with the 300psi Compressor motor and weve seen it damage a few bots, including our own. Just resently it bent 5mm thick tangent teeth on impact with a robot, and we were surprised it was going to even get the much power. I cant wait to see it with the 24v EV Warrior