Flywheel power

We use a flywheel with two green motors and a 7:1 gear ratio. It only shoots about half of the height of the high goal. We don’t have any access to flex wheels, so we were using the wheel attached below, with mesh and then rubber bands around it. The disc has just enough tension to a plexiglass part where the wheel has to squeeze a little bit. Could it be a problem with the angle that the robot is shooting the disc or what would be some possible solutions for this? Blue motors?

Screen Shot 2022-11-14 at 6.02.48 PM

We can best help you if you share a picture or video of your flywheel setup.
But the current issue is that you are only running green motors on a 7:1, which is not fast enough. Try 2 blue motors on a 5:1 ratio.

2 Likes

Is there a difference between the 7:1 and the 5:1 ratio for blue motors?

one is 4200rpm one is 3000rpm. also you could try to increase the angle of the flywheel

2 Likes

7:1 tends to be a little too powerful from my (and many others’) testing. 5:1 is just about perfect though.

2 Likes

Ok, thanks for that. It wasn’t nearly powerful enough for our green motors, so I’m assuming the green motors were the problem?

Yeah that could be the problem. Let me. try and send a photo of what angle it is at right now

1 Like

im assuming its at a 25 degree angle, do we need to make it more like 45?

Green motors are a much lower rpm than blue motors, as blues run at 600rpm. This allows for higher rpm’s when blue motors are geared properly.

I’ve found ~45 degrees to be the optimal angle to shoot from right around the outside of the low goal (and a little inside it). I’d start with 45 degrees and then fine tune it from there.

2 Likes

nah 45 is to mcuh i would do 35-40 i run 41 right now and i can make shots from 2-8feet

1 Like

I’m assuming you use flex wheels?

The traction will you have will launch desks just fine. Just work on getting friction down, getting your tolerances where they need to be, and fine-tuning the launch angle

I would try to put it around 40 degrees. Also using those same wheels with rubber bands covering the wheel should work just as fine if not better

1 Like

Our flywheel design is using two metal 12 tooth gears and 2 84 tooth green gears. We have one motor that is green. Our system is a double reduction to increase power and speed. It is a 84 gear or the motor spinning a 12 gear on the same axel as a 84 spinning a 12 gears on the same axel as the flywheel. It is extremelt fast and makes the disc go about 8 ft.

Do you use a flex wheel?

You can increase power or speed, but not both. I’d go with a single 1:5 ratio, blue cartridge, and 3k rpm flywheel. You will see the same, or better, 8’ launches with reduced complexity & temps and increased reliability.

Using either 1) brain direct control or 2) code… what rpm is your motor hitting? What are the watts used?

Yes I did use a flex wheel

If you want to use a green (200 rpm) cartridge and hit 3k rpm on the flywheel, that’s 1:15 ratio.

That would be the standard 60 driving gear and 12 driven gear of a blue/600 rpm cartridge tripled to account for the differences in the gearboxes. So do a double gear increase 36:12 into a 60:12.

According to my research and past experiences, the way to fix it not spinning fast enough is to add more motors. My team right now is running a 4 motor flywheel and extreme speed ratio which spins at around 14,000 RPMs. this was necessary for us to do because the standard VEX motors simply don’t have enough power in small quantities. There’s my advice