If you have a shooter with rollers on the top and flywheels on the bottom, is it reasonable to power the rollers with one motor and the flywheel with one, or would be better to just drive the flywheel with 2 motors and connect the rollers with a belt? Below is some stuff I thought of, if you have any insight please let me know.
Pros of separate motors:
Finer control of spin
Less weight
Cons:
Uneven load distribution
Harder to change flywheel speed depending on the range and get same consistency
Does anyone have other concerns, pros, cons? Thanks!
From what I’ve observed by tuning dual flywheel shooters, it is absolutely critical that both flywheels are spinning at exactly the same speed. Any notable difference in speed between the flywheels can greatly change the trajectory of a shot.
For that reason, I suggest connecting the rollers with a belt in order to keep them at the same ratio. That way, you don’t have to wait for the speed of both flywheels to stabilize before shooting (which is slow), because the speed of the flywheels doesn’t matter as much as the difference between their speeds.
Yea, the problem with that is that we would have different-sized flywheels on both. One would be a flywheel, one would be multiple active rollers with relatively little mass. This is exactly what I thought, thank you very much.
Would the trajectory be more consistent if you defined a constant ratio between flywheels while keeping each operated by its own motor? Eg. If you decided that a 2:1.5 provided good spin and good shot, then set the program to maintain this ratio at all flywheel speeds.
Last year we use a belt to move the rollers. We used 2 redline motors with the gearbox. When we used it the shooter start to bend inside so we put a stabilizer outside of the shooter in the gearbox part. This year we will put 1 in each side.
The advantage of controlling it through the program would be the ability to tune the backspin so the shot responds well when it hits the upper hub target. Teams would not know what is optimal without testing so they would not know what flywheel ratio they should use when designing the cargo shooter.
I guess a compromise to this would be to test with the rollers separate and operating in code under a certain ratio, then when an optimal ratio is determined, mechanically connect them. I wonder how much precision in terms of RPM difference you could get out of the ratio though. Gears and such produce discrete pairings, whereas if they’re separate you have a close to continuous set.
That’s actually what we may decide to do: test the ratio in code and then link them with belts or gears later. That makes me wonder if the data we get from the separate motors will be indicative of anything, because of independent deceleration etc.
