Flywheel Motor Overheating

Hey! So, we are currently running a 3000 rpm flywheel. Its well supported and spaced properly etc. Found that it overheated fairly quick, should be enough for a match but wanted to see if we could improve how long its able to operate properly. Our gears and motors are like 4 years old, so wondering if lubricating them would be worth it/would actually have an impact. Any help is greatly appreciated!

I assume you are using a 1 motor flywheel (correct me if I am wrong). Also, what wheel size are you using (a larger wheel will have less torque)? The most likely culprit is friction. I would recommend taking the shaft out of the motor and free spinning it. It should last a couple seconds. Pictures will help too if the source of friction is obvious.


My bad, I should have specified that. It is a 1 motor fly wheel and we are using a single 4in 30A flex wheel. When we build we keep our spacing 1 metal washer short of what it should be (we space the structure correctly so nothing is being forced) to ensure free spin and get 5 seconds + of free spin without the motor. There are also only 2 gears, a 60 tooth on the motor shaft and a 12 tooth on the flywheel shaft. Ill be able to send a picture in an hour or so after I get back home. We also make sure there is not metal on metal and stuff like that.


That sounds pretty good. Couple more ideas though. If your flywheel is really tightly compressing the discs, than the flywheel will transfer more of its energy to the disc. This means that it is drawing more amperage to get back up to speed and will overheat faster. Make sure that there isn’t a lot of friction between the disc and whatever it is sliding on when it enters the flywheel.

Also, are you leaving your flywheel running an entire match, or do you let it stop in between disc volleys? If you have your flywheel stop at the end of each volley, you will transfer the energy from the flywheel back into the motor in the form of heat. You can try running the flywheel the entire match, and it will help if you have low friction. Or you can build a ratchet which would be the best solution for overheating albeit a bit more work.


How long is fairly quick? What 9motorgang has said helps, but it might be that your flywheel is running about how much everyone else is. How long do you think the flywheel should run for? why?

1 Like

Tysm for the advice! We’ll definitely try that out:)

It lasts between 3 - 3 1/2 mins while just spinning. I believe we can get off like 25 -30 shots before the motor slows down due to the heat. I know that this is technically enough for the duration of a match, but I just wanted to ask around to be safe, as we had a 6 motor drive rebuild for worlds last year which seemed to run long enough for a match in practice, but would start to noticeably struggle towards the end (last 15 seconds) of our matches at worlds.

That is a bit short. I have logged my flywheels motor’s data over a 10 mins and it stayed at speed. It also showed signs of the motor firmweare limiting the motor(or somthing)


Ahh, alright! Thanks for the info. I’ll try doing the same and see how our motor compares.

1 Like

If possible, you should aim for at least a 10 second free spin on the flywheel shaft alone, 5 seconds isn’t bad, but you should push for a little more.
Also just going to mention that a 30a flex wheel expands quite a bit when it’s spinning, which can turn a 4" wheel into a 5" wheel, so account for that.


okay unrelated but I had a question about what you mean by this, does your flywheel also audibly slow down and speed up all the time? because of the motor firmware? because the same thing happens to us. we are trying to figure out how to get the flywheel to run smoothly

Nah, for us the flywheel runs fine, it just heats up in a few mins and then slows down as a result of the heat, making it useless.

All motors should do this, our drivetrain last 7:12 seconds of constant speed.

You have a cantilevered flywheel, which is more likely to bend and introduce the wobbles.

You have triple bearing secured the flywheel as well, which will lead to further alignment issues.

Your top C channel needs to be 2 holes longer so that it can be secured to the lower c channel via standoff. You need multiple points to secure the two c channels to make them as parallel as possible

You are missing a nut and have used keps on the other screws. These are more liable to come loose, and a loose bearing is a useless bearing.


@AperatureLabs has a number of good points.

  • How do you guarantee that the cyan and green lines are parallel? If they are not perfect you will have friction.
  • Since there isn’t a bearing / c-channel mount on the top side (pink line), the wheel can wobble out of balance and create stress and friction on the axle.
  • The more points where your axle touches the robot, the more friction it will create. You need to balance the proper alignment against the number of friction points (red arrows) .

A good test is to remove the motor and see how long the wheel will spin with one manual push. If it spins like a top, you are in good shape.


This question is off topic, but how did you make that chart? Did you write motor values to a spreadsheet or something then import to Excel?

It seems like a really useful tool to have.

This promted me to make a thread on how to graph motor data:


Thank you! It’s a great resource.

Thanks man, got valuable information from your post.

1 Like