Motor Issues

Our motors work at full speed for a solid like minute and then the speed goes down until the motors rest for a while? Any thoughts…? Some of the motors aren’t even doing heavy lifting, the drive train stops also

v5 or 393? What gear ratio

V5. two of them that don’t work are 1:1, two other ones are 15:1, and two other ones are high torque but don’t know the exact gear ratio

The 1:1 are for the drive train and the 15:1 are for the flywheel

How many motors for the drive? Do you have the newest firmware? How many motors for the fly wheel?

Might be a code issue.

How should the code be written?

This is ours: any issues?
Screenshot 2018-11-08 at 5.01.36 PM.jpg

We’ve been seeing the same problem. We have 4 v5 motors with speed ratio internal and 2:1 speed ratio external. While running normally, the drive motors each draw 3.4W. When the issue starts, the motors start drawing only 1W each. They don’t heat up drastically and battery voltage doesn’t effect it at all. Restarting the program or microcontroller doesn’t work either. We’ve seen the problem with multiple programs and we don’t think it’s an issue with our teleop code.

I know that this is really late, but my team was having the same issue. Our flywheel (50:1) was reaching the current limit and stopping. I think that we ended up having our code repeatedly run the flywheel at the desired speed, which overwrote the limit and allowed our flywheel to continue spinning.

What are the internal temperatures of the motors?

50:1 is a bit overkill I would go tops 35:1. I use 35:1 on 3 speed 393 motors and it lasts a long time. I recommend also using a ratchet which aids in reducing the amount of energy that may back up into the motors

Although you guys are using the graphical version to code with VCS, I’d recommend learning text-based coding with PROS, C++, C++pro, etc. because it could be more organized and more familiar to most.

But to get on topic, this sounds more or less a problem with friction or overworking. Some questions I may ask myself would be as follows:

  • Is there any friction on the axles, such as are they easy to turn with minimal force with a gear or wheel?
  • Does the problem persist after giving the robot a 30 minute rest? (The V5 motors do get pretty hot sometimes)
    A 15:1 200 RPM gear ratio is 3000 RPM which the flywheel shouldn’t burn out at such a speed. Same thing with 1:1 for the drivetrain. So I am concluding that you probably need to keep an eye on build quality, as well as make sure the axles move in the bearing flats as easily as possible.

Our flywheel works now, but thanks!