Hard to turn high speed motor

VEX V5 Technical Support
1

Hey everyone! So we were just testing our holonomic drive and suddenly, one of the wheels stopped moving. When we turned off the robot and tried to turn that wheel manually, and it was really hard to turn it compared to the other wheels as it was providing a lot of resistance to turning(We have four - 4" wheels each connected to a high-speed motor in a holonomic drive arrangement). That motor was working fine for the past 10 minutes of testing. This actually also happened yesterday to another motor, but we replaced it for a new one thinking it was faulty. As I mentioned, another motor is having that problem today. We checked for any structural friction issues but there are none (it was turning smoothly just a while ago as well). It would be great if we can get some idea of the causes of this problem and any way to fix it :slight_smile: Thanks
Ps, we are sure that that motor is high speed

2

Do you build your motors? Someone might not be doing a very good job.

3

Umm, we do change the internal gears from high torque to high speed. Not sure, about what building the motors means sorry.

4

That’s more or less what I mean. It might be an internal gearing problem

5

We will surely check if that is the case, but we are a bit confused about how it wasn’t hard to turn 10 minutes earlier.

6

I would try a different motor all together.

7

The internal gears can chip and the chips can bind the gears. I would expect if you open the motors you will find damage to the internal gears.

8

This exact thing happened to me - Replaced the motor 4 times, the internal gearing 5 times, and the integrated motor encoder 2 times. Exact same wheel froze up every time, and everything was inserted correctly. Same holonomic highspeed 4" drive, who knows what’s causing this.

9

We’ve had this problem too. I personally rebuilt a motor 4 times and had to replace one twice. Your best option is to COMPLETELY rebuild the corner of the holonomic drive that’s locking up. This means Axles, metal, bearings, everything. Also, replace the wheels that you’re using.

10

I would also think programming with slew rate control would help reduce stress on the internal gears. (Search for J Pearman motor slew rate code.) Holonomic drive probably has more rapid shifts of motor direction than tank/arcade.

11

Hi everyone! Thanks for all the advice. Today, I completely opened up the motor and replaced every single internal gear and the problem still persisted. I think I have narrowed it down to a problem in the internal standard motor itself. I will definitely use slew rate code to prevent any further damage. Thanks again for the help :slight_smile: