6/13/2009

Sean Brennan

Beefy, dependable motor.

I've purchased 10 of these motors over the years, and this has become our most trusted motor for quick robot builds. I have no hesitation buying more. It's quiet, dependable, and exceptionally beefy... perhaps too much so (see the amplifier issues below)

Pros:
- quiet operation
- dependable. I've never had one break, and that's something I cannot say about most other motors.
- has numerous mounting points on the body for many attachment options
- can easily move hundreds of pounds
- the output shaft has a convenient bolt pattern that is relatively simple to adapt to a direct-drive wheel/tread system

Cons:
- It's heavy. Wish there were a retrofit casing to replace the heavy standard casing.
- It's so powerful that it will easily bend a frame if the frame isn't up to the torque output.
- There's not an easy way to mount an encoder to this thing. This is a big frustration for using this on an autonomous robot.
- wires seem under-rated as they heat up under moderate load. We replace them with welding cable immediately now. For this reason I've never run them more than 24V.
- hard to find an amplifier strong enough to run them. We've been using the Roboteq 25xx series devices, and although the Roboteq manual specifically warns against motors larger than the current limit, we've noticed little problems as long as standard precautions are adhered to. But it will eventually blow the motor controller if startup/shutdown instructions in the Roboteq manual are not followed, for example if repeatedly switching on/off motor power using a battery disconnect instead of the proper enable/disable lines.