Hi all, I wanted to test out the impact of removing the motor side bearing on our drivetrain having read some of the posts about doing this. Currently we’re using 200rpm green cartridges so the motors are connected directly to wheels, meaning that the drive shafts are load bearing. Rather than do this directly on a robot, I did a test rig that simulated a driveshaft under about a 5lb load (which would be a 20lb robot distributed across 4 wheels - maybe a bit on the high end).
To cut a long story short, I did not see any (visible) damage on the cartridge but the driveshaft did grind the c-channel hole substantially and notch the driveshaft.
Motors with blue cartridges would not be setup in this way and would be protected from a direct load of course.
Longer story …
Here’s a sample slice of our drivetrain (although we’re currently using 4" wheels).
Here’s a picture of the test rig:
4 rubber bands stretched to 5" gave about 5lbs of load. Gear using gold (round) adapter of course. The bearing visible in the picture was removed for about 6 hours of test time and was present for 6 hours (motor only spins if below 50% temperature, so total run time for motor is about 2 hours).
Here’s a closer up of the planetary gears in the cartridge after the tests (still looks pretty intact, but I’m not quite sure what I’m looking for.
State of the drive shaft and c-channel hole after the “no bearing” test cycle.
Net, I would make sure to understand the loads involved on the driveshaft when determining the right bearing configuration. Maybe stating the obvious.