fly wheel trouble need help

My team and I have built a fly wheel launcher with four motors and after 45 seconds the motors stop and sound like the are they are moving. I thought they are heating up, but after 10 seconds you can use them again for 20 seconds. So I would like to now if the motors are heating up or if there is too much stress on them if so how can I fix this.

You should check the binding and friction. With our fly wheel, we sprayed WD-40 into all the gears and the gears inside of the motors that run our flywheel. Also if you have metal gears you should think about replacing them with plastic or high strength gears because the small metal 12 tooth gears cause a lot of friction. We had this exact same problem and did this, now it works like a charm.

There could be several issues here:

  1. You are tripping the PTC in the cortex. This happens when you exceed over 4 amps per circuit. You have two circuits on your cortex, port 1-5 and ports 6-10. You need to ensure you are spreading out your load across both circuits, and maybe even add a power ex-pander as that gives you a third 4 amp circuit to work with

  2. Just because the motor does not feel warm, does not mean you haven’t tripped the motors PTC. What you refer to as “burning out” is when the motors PTC trips. A side effect of drawing a lot of current threw your motor is that eventually the PTC will trip, and you experience symptoms of your motors “burning out.” Because you are tripping your motors after such a short period of running, that means that you are drawing too much current at one time, and your motors cuts off power because it is not safe. If you wait 5-30 seconds, it will start up again because the PTC is going to allow current through again. Basically, this means your motors can not handle the load.

Basically it sounds like your motors are not “heating up” but rather there is too much stress on them. To fix this i would recommend a few things:

  1. Make sure that your axles on the wheel and gearbox are not bent and all have bearings
  2. Make sure your bearings are on screwed in tight, and consider adding grease to inside the bearing to allow the axle to spin in it easier
  3. If you are using a 5" high traction wheel, be sure to evenly zip tie the rubber down to the wheel rim, as it keeps it from stretching out and causing an imbalance in your flywheel.
  4. If you only have two motors, it needs to be a very frictionless and well aligned launcher, and may want to consider adding 2 more motors. If you do have four motors, then it just means something is not aligned properly.

If your alignment is correct and your axles are straight, you shouldn’t be having issues with it burning out. We have a four motor single flywheel, and after much alignment and fine tuning, we were able to run it for 30 minutes at full speed constantly launching shots and they don’t burn out until the last few minutes of that. If you check your alignment with a very careful eye, it will pay off. Then consider adding small amounts of grease, but keep in mind that it does not make a huge difference. Grease really just helps to protect and keep running an already well assembled flywheel.

I hope this helps, and also pictures would be nice! it helps us here on the forum understand your issue better

we had this similar problem when we switched to a higher gear ratio. we already have heavy wheels and we could only run them for 30 sec before the motor PTC would trip. the tension on our first compound was also a little to tight. When you are dealing with these higher rpm’s, things like this make a much bigger difference than if you are dealing with a drive. We are having no problems now that we have made these changes.
Grease is scary to me, but if you are willing to keep maintenance and know what you are doing, go for it.