DeWALT Transmission After Action Report

[Richard Wallace]

931 built two NBD units using 2004 FP motors and 10-tooth #35 sprockets, following the white paper recipe almost exactly. We did adjust the pinion hole diameter slightly to get an easier press fit. Based on gage pin tests I think we ended up with about 0.1255".

One NBD-FP is on our robot actuating the arm pivot chain, the other is a spare that we have not needed yet. Arm radius measured sprocket-to-hook is about 4 ft. Sprocket reduction is two stages for 36:1 and then the XRP gearbox in low. Motor current measurements while lifting a vision tetra indicate less than 25A average draw [note: motor current is discontinuous with instantaneous peaks to about 45A, chopped at Victor modulation frequency], and our PWM code limits the average motor voltage to about 9V max. So far no problems, but we did have to remove the anti-backdrive pins to permit stable lowering; having the pins out makes our arm operator much happier while capping.

I'll report again after the championship.