#2738 Gearmotor performance issue

#2738 Micro Metal Gearmotor MP 6V on new Pololu 3pi+ 32U4 Robot

My robot is new having just recieved 3 days ago in thebpost. I have noticed a significant change in performace, for nonchange in code. Right wheel/motor appeared to be dragging.

Closer inspection there us black something coming out of the small holes in the brass looking plate on the end of the motor.

Suspect this may be cause.

Comparitive testing against three other robots of same specification indicaged my robot is underperforming by about 2 second over a maze for which the the other robots are completing in 56seconds.

Is this a manufacturing fault??

My 3π+ robot that has a few weeks of wear and tear on it does not have any grease (or whatever) leaking out of it like that so I suspect that it’s not normal but I am also not running my robot at top speed for long periods of times either. If the motors were overheating then it might make the grease thinner so that it could leak out a bit like that. If you touch those brass plates with your fingers after a few maze runs is the right motor hotter than the left one? Knowing this would be another datapoint for the Pololu team to use when trying to diagnose your issue.

It sounds like it worked better when you first got it but as the days progressed it has started to show issues. Is that correct?

I guess one environmental/code issue that might cause the right motor to wear worse than the left is if you are running the bot quickly through a maze which causes the right motor to slam into reverse more often than the left because there are significantly more right turns in your maze solution.


Grease escaping the gearbox is not necessarily a problem, and a deviation of two seconds over a 56 second maze course would also fall within normal unit-to-unit variations of the components (and could also be explained by external conditions like dust on the tires).

Can you better quantify the “dragging” of the right motor. For example, what is the speed difference between the motors as measured by the encoders when you run both at full speed in air?

- Patrick