Single flywheel issues

Hi everyone
We have a 1:21gear ratio with high speed which is 1:33.6. How flywheel shoots 7 feet, but it can’t get any height at all. We don’t understand why it cant shoot full court.

(If you need more picture tell me)

  1. Check the angle of your hood.
  2. Check the compression between your hood and flywheel.
  3. Check if all motors are plugged in and running.
  4. Check for friction.

If it’s a single flywheel, make sure the ball rolls off the hood at the right time to still have some vertical speed. If you launch at too shallow of an angle, it won’t get any distance.

We tried to adjust the hood and we can now get more height. We also increased the speed of the motors from 80 to 95. We were able to shoot right into the low goal with very high compression, but that significantly lowered the speed of the wheel and we don’t think that’s healthy. I’ve attached some pictures here.
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When you say “very high compression”, how much compression are you talking about? .5"? 1"? My team has found that our single flywheel works best when the ball forms a flat surface about the size of a quarter, which is not a whole lot of compression, and that might even be more than necessary. Reducing compression maintains more energy in the flywheel (less slowdown).

I’m not really sure how to measure it, but I will post some pics when we put the hood and intake back on. We took it off to try a stronger way of mounting it. There was a little flex in the hood which might have been reducing its grip on the ball.

We use to have a four motor flywheel with the same gearing setup, and we were able to achieve full court at around speed 60-70. One suggestion that maybe you should consider trying, is using the very end of your intake as the hood. In other words, get rid of the hood you use right now, and just use the intake to give compression to the ball to launch it. We found that our flywheel was just as accurate without a dedicated hood while using the intake (conveyor belt) as a hood too.

Also check your flywheel for friction. I see shaft collars that are against metal (from what I can see, I could be wrong) and that will cause a lot of friction, and you will lose a lot of the energy in heat caused from friction. If you need to use a shaft collar that goes against metal, add a small nylon washer so that the washer is in between the shaft collar and the metal. Also make sure that all your spacers that you used in your gearbox can spin freely.

Sorry if it is a little confusing to understand, feel free to ask me any questions you have. :slight_smile:

What bps can you achieve by using 60-70 speeds?

I did not measure measure how many bps I was getting as I was getting these results when I was testing the flywheel with motor values, but I was able to launch full court with a constant speed of around 60-70. However, after I tuned TBH to a decent amount and put it on the flywheel, I was able to get about 1.5 balls per second. If I had a perfectly tuned PID controller or bang bang on my flywheel, I am sure that I would be able to get two balls per second (maybe more). I did not spend a great deal of time tuning it as I did not have much time before the competition, but I can say the build quality of the flywheel was excellent, as it was a single gearbox and it was meticulously built, being tested after every stage. At that time I had two five inch wheels as my single flywheel, but if I were to increase the mass I probably would have gotten an even better bps. @spartanshl

Ok I will try that. Thank you so much.

Also, would you mind telling me some good resources for TBH. I have no idea how to make one. I have a PID programmed right now, (I’m not using it right now) but I don’t know which target rpm I should set. I am just looking for an estimate and then I can fine tune from there. Once again thank you for assisting us.

We started with 3 5" wheels, and our fire rate increased dramatically when we removed the third wheel. It also reduced our spin up time from 11 seconds on a 28:1 gear ratio with 4 motors, so there definitely is a sweet spot on inertia.

That is true, and that reminds me of a question I have had all year. Is it better to have a lower mass, or a higher mass? And in what case or situation should you choose a flywheel with a lower or higher mass. I have seen that many teams have gotten different results. Some use a single five inch wheel while others use four four inch wheels. Have you happened to figure this out yet?

I think it is better to either have a very heavy flywheel or very light flywheel. I say this because I think that with a very heavy one, you barely lose any speed, but if you have a very light one, then the motors can easily bring it back up to speed.

My Flywheel runs at 25 mph after all the friction of the gearbox but i am not sure if it is enough to actually shoot.

Well 6096 here. We see you guys have completely changed your design from states. Hmmm…Well, see you guys at worlds anyway.

Hi 6096. Didn’t you guys change your design too? We just want to be good at worlds. Oh well, see you there. Good luck.