What motors do you use to drive your robot?

[Cory]

You might want to add Drills+CIM's.

As for your question, either one will prove to be fine. The Drills have a bit more power than the CIM's. They can be shifted using their transmission if you wish, and you already have the mounts and gearboxes if you dont want to make a chain and sprocket drive. People have voiced concerns with the integrity of the transmissions, but if you do it right, there wont be any problems. Also, the drills wont backdrive in their standard configuration, which may or may not be an advantage.

As to the CIM's, they are very easy to mount using the holes on the face. (10-24, I believe?) They still have a good amount of power, they don't overheat as often as the drills. They don't have an anti backdrive feature like the drills. They are also a bit heftier than the drills. One plus is that they spin at approximately the same speed forward and backward, unlike the drills, meaning that your robot wont drift to one side constantly.

Cory

[Atman]

We used the Atwoods last year with our two speed transmission and they seemed to work just fine. We are probably going to end up using them again. We had them geared just right and they gave us the power to push anyone we wanted around in low gear running at 4fps. Even in high gear we were able to push a lot of the competition around at 10fps. No problems with overheating. In years past we did use the drill motors and they were effective.

[Matt D]

In past years, we have gone with just the drills (2001, 2003). In 2002 we used the drills and the CIM's with a complex and heavy chain & sprockets transmission (We didn't have a machine shop).

Last year we just used the drills, shifted them with servos, and geared them down with chain. It worked well, although we had trouble overheating during the playoffs. We fixed that by cooling them with canned air (which is freezing cold).

It is much easier to go with just the drill motors.

[sanddrag]

Originally Posted by Cory

The Drills have a bit more power than the CIM's.

If my calculations are correct, the Chias have more torque at 40 Amps than the drills. But the drill does have a higher stall torque and is overall a more powerful motor.

[Joe Ross]

Originally Posted by sanddrag

If my calculations are correct, the Chias have more torque at 40 Amps than the drills. But the drill does have a higher stall torque and is overall a more powerful motor.

It doesn't matter what motor has more torque at 40 amps, its what motor has more power at 40 amps. You can change the torque by adjusting gear ratios, but you can't change the power.