Need some help with flywheel

In theory this should work, but it doesn’t. It worked perfectly without the top set of gears, but as soon as I added them along with the wheels everything began locking up. Any ideas on what it could be and how to fix it? If not that’s alright, it’s just something that I was playing around with, lol.

Edit: Thanks for all of your responses. I’ve fixed it (with the suggestions from y’all) and it’s working.

1 Like

The problem is the iQ gears. They cant handle the stress like the normal vex gears.


The gear ratio is kind of high 7:3 x 7:1 x 5:1 = 81.6 : 1, while most flywheels from prev seasons were around 30:1.

But IQ gears themselves are fine. It is metal pieces that are not connected and bent that are creating a lot of friction. That makes it impossible to run with such high gear ratio.

First, you need to connect metal pieces with standoffs, so that they could free stand without axles.

Then you need to attach each bearing block with two screws and make sure that they are very well aligned. Axles should spin freely when you insert them without gears.

Then you start adding gears and keep checking that everything spins freely and there are nylon washers between shaft collars and metal.

Finally you insert axles into the motors.


That gear ratio is way too aggressive for so few motors, especially if they are 200RPM or 600 RPM internally.


I would use c-channels instead of flat plate, as flat plate bends easily and I can see some bending in your photo. As @weilin suggested, try using many standoffs to align the c-channels pieces so they are perfectly parallel, and make sure the axles can spin freely in the bearings. Also try to make sure there are no collars rubbing directly against metal, plastic washers can help. I see that your motors are not screwed into the metal, not sure if you were testing it like this or not, but they should be tightened. Hope this helps!


This is correct, I have a flywheel design that we used during the Nothing But Net Season that is the exact same concept as this one. With 4" wheels, like the one you are using, we used a gear ratio exactly like your first 2 sections of your build. And it was with the old V4 motors.

Keep in mind, we were shooting soft foam 4" balls that could be compressed, what are you trying to launch?


That looks pretty sketchy… Now, some say that I use too much structure (I built a 57lb robot earlier this season and a 28lb robot last season) but I would suggest at least replacing the sheet metal with channels and ideally, putting a frame around it so everything is connected. Check for friction as well. Oh, and please please please don’t use IQ gears. They are not the same as EDR gears.