Drivetrain Overheating Problem

Last season, I built a robot that had 4 blue 600 rpm motors powering six 3.25 in wheels on a 60:48 gear ratio, gearing down. I used blue motors since they have less slop than green motors, and geared down to have some torque and not all speed. But just after about 15-20 minutes of continuous driving practice, the robot would just start stuttering its movements and could barely move forward an inch.

Is this just happening because the robot has been driving for too long, or is it a gearing/motor problem? And should I keep using the same blue motor combination gearing down, or is it better to use green motors and slightly gear up?

This is a gearing problem. 4 motors at 480 RPM is just not enough to provide sufficient continuous power to your base. For reference, we used 6 motors at 480 RPM at worlds and still needed to hotswap them between our elimination matches. Either add motors or slow down.


I’d say you were just driving for to long, my team would only get 7 minutes on our 360 rpm 4 motor 3.25 inch wheels robot. 15-20 minutes is a surprisingly long time. Vex motors will just overheat after so much continuous use. You can turn a can of electronics duster upside down and spray it on the motors to help them cool off faster.


canned air like @Skibub28 said is a real life saver for overheated motors. Always have a few cans at a competition.


Follow the data. Display your motor watts to the brain/controller or log them and look at the average after the run.

You can pull approx 5 watts continuous for a 2 min match w/o overheating.


I would say this is expected. You drove the robot for 20 minutes straight. Some of the best team’s bots only last 5 minutes.

During a match would your robot experience these problems? Stalling motors is fine, as long as that doesnt happen during a match.