I have seen some teams use a heavy metal disk of some kind to increase flywheel inertia and make each shot consume relatively less energy out of the system. Are there any COTS solutions compatible with a half inch hex axle or is there some better way to solve this problem?
Look out for these when they come out
Whoops missed that post. Thank you!
Since you say “relatively less energy”, you probably know this already, but for other people that are reading this thread, I want to point out that flywheels do not change the amount of power that you need to use to spin your shooter.
Flywheels are used to increase the moment of inertia of the shooter, or, roughly, how much the spinning stuff resists changing its speed. Adding flywheels reduces how much your shooter slows down after each shot, but also makes your shooter take longer to speed back up. Specifically, each shot extracts some amount of energy from your system, and so your motors need to be able to put at least that much energy back in before the next shot:
\frac{energy\ out}{shot}\cdot\frac{shots}{time}=\frac{energy\ out}{time}=power\ out \leq power\ in
Basically, flywheels don’t magically allow your shooter to work with less motor power. What they do is to slow down the “impulse response”, how fast the shooter changes speed, which makes control systems math (like PID loops) a bit happier.
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Adding a few 72 tooth gears to the shaft or even some (extra?) colson wheels would be a very simple way to add inertia to the shaft.
Just make sure that whatever you’re adding to the shaft is both well-balanced and can handle the rpm, and test it rigorously with everyone out of the way–well out of the way. Super-duper out of the way. Wheels/flywheels delaminating or flying apart at high rpm are extremely dangerous, whether they’re made of rubber or anything else; probably the most dangerous thing on any given FRC robot if they fail.
To add to @CarlosGJ’s excellent response, where flywheels can really shine is by minimizing the decrease in shooter angular velocity for each shot. In addition to making your control loop a bit happier, maintaining a more consistent shooter angular velocity throughout the shot results in a more consistent ball linear velocity and a more consistent ball spin coming out of the shooter. More consistency means better accuracy means more points scored per shot on goal.
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As I said in another thread, a small piece of flywheel shooting off has about the same speed and energy as a civil war bullet. Extremely dangerous and quite possibly deadly.
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I’ve used AndyMark’s 56 tooth steel gears with a hex bore as a flywheel.
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