So my team is thinking about redesigning our shooter after our first competition. Right now our shooter can shoot balls fine but we have to wait for it to build its speed back up after each shot. Does anyone know how teams are shooting 4-5 balls back to back without losing velocity or having to wait for their shooter to build speed back up? Thx
Yeah we had a similar problem. We found that adding inertia disks or more wheels to the shooter helped a lot with that issue and made the shooter more repeatable and the deceleration after each shot was negligible.
More motors or more mass.
- More motors
- Better gearing
- More mass
- Designing to take a slower shot that requires less energy.
I can’t speak mechanical wise, but are you running a velocity PID loop on your flywheel? Well tuned controls are a big part of shooting success.
We are running a horizontal wheeled shooter (like a baseball pitching machine) with one 4" Colson wheel on each side. Each wheel is directly driven with a NEO.
We haven’t had any issues with waiting for the motors to spin back up to speed or with losing significant velocity while shooting.
You need to worry about mass, and can the wheel hold the wanted speed. We found that without enough mass on the roller we lost about 12% of our motor RPM, sure it recovered quickly, but still thats alot for only one powercell.
Shooters work by transferring energy from something that is spinning really fast to a ball. The key to being able to recover quickly is to have a lot of energy in that thing that’s spinning really fast.
To do that, you have two choices: First, spin it even faster. The amount of energy stored is proportionate to the SQUARE of the angular velocity. So, increasing speed will definitely increase energy. But, that will also increase the speed that your ball leaves your shooter, and you may not want that.
The other way is to increase the moment of inertia of your shooter. To do that, increase the mass spinning on your shooter wheel (or on a shaft connected to that wheel). Try to have as much of that mass be far away from the shaft itself, like a bicycle wheel. The AM-0164 gears are great for this – they’re heavy, but the weight is mainly on the outside.
We added a 4# flywheel to our shooter. It’s steel 4” in diameter x 1” thick with 1/2” hex. Works well.
But be aware that the more mass that is away from the shaft, the higher the internal stresses on the materials, and consequently potential for failure. See this thread Flywheel Do's and Don'ts that has a lengthy discussion occasionally interspersed with information about safe shooter RPMs for Colsons, Fairlanes etc.
A lighter, wider hoop with more mass spaced farther out can both weigh less and give a greater moment of inertia. Something to consider for future years.
More mass on the shaft (like a weighted flywheel) will cause it to have more angular momentum. Most teams with these types of shooters have weighted flywheels which allow them to retain their speed.
Two Colstons two 775’s 3:1 and lets go! and seems to be good hooded at 67 degrees (first successful HG shooter ever) not to be underestimated as a solid plus in points in huge outer an doable inner goals.
We have flywheels and each has its own connected to a neo with no gear box. However our shooter weighs a good 10 or so pounds only because of the inertia. We also have a quick intake to stop the inertia from slowing down to much. You can probably find easy solutions then rebuilding if it works well.
Is anyone going to tell them?
Shh they’ll have more fun now if they find out later
Also PCH hasn’t cancelled… Yet
This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.