I’ve asked this question when we had a new team before and I thought we had learned our lesson. My 3rd grade team is trying to build a flywheel shooting mechanism. Everything looks right to me but I admit to not knowing much beyond what we see on youtube. The kids have built this mechanism but the motors refuse to turn. We hear them working but nothing is happening. Can anyone see anything we maybe missed? I don’t know what’s wrong. I’ve included a pic below.
Are the axles for the motors inside the motor? If not check if you can roll it with your hand if you can maybe the motors are bad? If you can’t roll it with your hand it’s hitting something most likely.
yes they can move everything easily with their hands. It even moves with the motors attached. Just when they power it up and try to have the motors run it doesn’t work. They also tried changing out the motors for new ones and it still won’t turn.
Have you tried switching the ports and or cables? It may be a dead port or bad cable.
Do the axles move freely, or is there some resistance? If there isn’t any resistance or if the motor’s don’t make sound when the axles are spun, I’d assume that the shafts aren’t even inside the motors.
That’s an aggressive gearing ratio for speeding up. It would work well as a reduction in the opposite direction to provide higher torque, and that illuminates a likely problem. Whatever resistance to turning the shaft with the tiny gear is experiencing will act on the shaft of the larger gear multiplied by the gearing factor.
When the receiving gear is very small, the levering geometry between the teeth of the two gears can be an issue.
The initial stiction due to shafts bracing against apertures, magnified by the enormous gear ratio might be the problem.
If it was me, I’d rebuild it with a less aggressive gearing ratio to start searching for the issues.
If you want tactile insight into the situation, take the motors off and replace them with a shaft and a gear that you can grab hold of and turn. You’ll feel how difficult it is.
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Assuming they are doing a motor group, sounds like maybe one of the motors isn’t spinning the right way in the setup, so they are going against each other and basically locking up.
Did you look at the picture? It clearly shows they are not connected in any way.
Looking at the picture provided, it doesn’t appear that the motors are connected in any way to act on each other?
Oops, missed that. 
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update. we changed the motors out for new ones and added those skinny washers to every part that looked like it would rub against something. Now when they test the motors directly from the brain, they work. However when they try to run both motors together from the remote they still don’t work. I honestly don’t know what the problem is now, Why do they work individually but not together? I will admit I have a LOT to learn about coaching this stuff.
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Send a picture of the code could be configuration issue
Could you also be more specific please about how it isn’t working? They don’t come on at all? They run in the wrong directions? They stop?
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The kids are out on break now but I’ll try to explain. When they turn on brain and test the motors using device info (Gen 1 brain BTW), there is a lot of squeaking and a slow start but the tires get up to speed fine. There isn’t any code…they used the motor group function and assigned a button on the remote. When they press the button on the remote the motors now make a high pitched hum , attempt to turn, then don’t turn at all. Or they turn and one is slower than the other. When the ball is introduced, they stop altogether. I can’t tell if it’s a friction issue or a gear ratio issue or both.
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If the motors don’t turn or seem to “struggle” with no ball, that’s the gear box - gear ratio, quality of build, or both. When they you get them to run smoothly and then they stop when a ball is introduced, that’s friction from compressing the ball too much.
IMO, fly wheels are extremely finicky and take a lot of patience and tweaking to get right, particularly with compressible/squishy game objects.
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