[DFTF] Motors... ...Drive Motors...

[JamesCH95]

I would vote CIMs in the drivetrain every day of the week simply because they have far and away the most OTS drivetrain oriented gearboxes of any of the motors.

Regarding AndyMark Products, I have used many and never had an issue with anything. I would not hesitate to buy anything from their catalog.

SuperNerd256 brings up a good point with weight, if the motor is going on an actuator somewhere higher up on the robot (the second DOF of an arm for example) a 13oz RS775-18 would make life a lot easier than a 45oz CIM with nearly the same power.

Last year I became an instant fanboi of the RS775-18 motor. It's designed to handle 18v, so the 12v we run it at is a cake walk. It has plenty of power. It has a bigger can (i.e. more thermal mass) and better cooling than any 550 sized motor I've seen. We used two (but could have used one) as the main shoulder joint actuator on our robot, stalling them to hold arm position, and never had a single problem.

The trap I see with any of the BaneBot's motors is that the BB transmissions can be had in ratios such that the attached motor will over-load the transmission if not properly controlled.

For example, the BB P60 transmissions are rated at 35 lb-ft of torque. The RS775-18 has a stall torque of 166oz-in = 0.86lb-ft. If a 256:1 transmission is used, it would be possible to push 220lb-ft of torque through the transmission. Clearly not a good idea. In my opinion the most fool-proof way to get around this is to not use any transmission of a ratio greater than 64:1 and use sprockets or gears for further reduction. The transmission could still see 55lb-ft at stall with a 64:1 ratio, but a little bit of current limiting in the control code should prevent damage.