Banebot Gearbox

[Brian C]

OK

For what it's worth I ran our teams 2 BaneBot trannys with single CIM's mounted on the workbench last night in a no load condition.

Note: this was after machining (ok grinding ) the bushing down to make sure it doesn't bottom out against then planetary. It was ground down to make the pinion even with the end of the CIM shaft.

The units appear to be lubed up nicely from the factory. However with experience being my guide I did add some light grease to the pinion (read: Vaseline) when I re-assembled the unit.

Initially the CIM's drew over 6 amps measured with a DC clamp-on. After running them for approximately 1/2 hour the current dropped to a steady 3.5 amp draw. There was a noticeable change in sound from the units as well during this break-in period. Not so much in volume as in smoothness.

One of the units did seem to have some issues when you flexed the motor/tranny assembly slightly while running. Note that all screws were tight. Once the current draw had settled to the 3.5 amp area I noticed that the slight flexing now had no effect.

After running each CIM for 1/2 hour the outer casing of the motors were each measured at 105 deg F. I was happy with this temp as 1/2 hour is a long run time for these motors. With last years KOP trannys our CIM's never came in after a match any less than 160 deg F.

This is well within what we consider a "safe" area. When drill motors were the main drive motors a few years ago the temp was usually around the "hot enough to boil spit" range so I'll take under 200 deg F any day.

Conclusions?

I would trim the bushing down and carefully assemble your units, keeping everything clean.

Break-in the transmissions and let them run for a while. This is good practice anyway and lets all the parts get "comfortable" with each other.

When mounting them on your robot I would carefully tighten them down to make sure you don't add any undue stress/flex. I would also recommend a support under the CIM's. A small piece of wood is the simplest.

Then drive the snot out of your robot base and see where any weak points may be.


This was our experience and as always your mileage may vary.

Good luck.