Power out during matches

Hi all,

It’s our first VRC season. Having a great time. We have 4 teams and they are all trying very hard.

However, recently we have been experiencing cut outs and power loss in matches. Any ideas?

One team have been practicing well and in last regional competed in 6 qualifying matches fine then in the 7th match first the right front wheel cut out then everything did. In all subsequent matches we were unable to use the lift after a couple of goes and the robot lost control of the drive.

One of our other teams experiences power loss after about 1 minute in competitive matches.

Very frustrating.

We have 12 motors all plugged in to the cortex on most of our robots. We have checked that there is no excessive friction and that all motors work ok. Batteries are fully charged.

Any help greatly appreciated!


In the back of every motor there is a PTC sensor this sensor measures temperature, if your Motors exceed a certain temperature it will cut power to the motor. When you have problems with this on a certain area a lot it means you either have a large amount of friction there which in your case you have checked or you’re running the motor too hard try running a slower ratio with more torque instead of speed.

Thanks do much for the response. We are running drive train direct from motors (not speed motors)… our lift has 6 motors and gear ratio is 1:5

We are not using power expander… do you think that is tue problem?

How many drive motors and what size wheels?

4 wheels on an x drive.

4" wheels.

Our other robots have 4 motors on drive train. All 4" omni wheels.

That could be the problem with your drive. The speed of an x drive is squared du to the odd placement it much faster, but very weak. Try tank drive or a smaller wheele size live 3.25 omnis.
If you want to know for sure if the problem is burning out try running your Motors or driving your robot around for as long as you can and then if you feel the motor and it’s at all warm that is definitely your problem.
Right now I am running my lift at 7 to 1 ratio not very fast compared to five to one but much stronger.
if you using Y cables on your cortex to Motors those Motors will be running about half so you might want to consider running a power expander to power those Motors.

Thats brilliant thanks. We are using y cables so i rexkon we need a power exander then! I think we’ll also go for 7:1 lift!

Thanks so much for your help!!!

No problem.