Bore diameter of piston?
 

Our team is wondering what the diameter of our piston should be. We're looking to kick the ball, at about a 30 degree angle, over both the bumps.
We need to know what size would be adequate to do this.

Re: Bore diameter of piston?
 

I know it's hard to experiment because as a newer team you don't have an assortment of cylinders to try. Our first year we were lucky enough to borrow some from other teams, and a 1.5x8" was included in the KOP back then.

We tried (2) .75 cylinders directly connected to a kicker, and got about 10-15 feet. Then we tried a 1.5", which was too slow but had enough force. We also found that you can't 'push' the ball, it had to be hit or kicked.

A few teams have posted successful threads about their kicker designs, you could research their methods.

Or if you get a kicker to work with springs / surgical tubing, you can calculate the force required to 'reload' the system, and order the length and diameter piston required to reload it.

Page 15 of the Pneumatics Manual has a chart of pressure/force for the cylinders. http://www.usfirst.org/uploadedFiles...%20Rev%20-.pdf

Also some great info here: http://www.team358.org/files/pneumatic/
Great resource Team 358, thanks!

Re: Bore diameter of piston?
 

I'm not sure of your design, but I'd strongly suggest against directly "punching" the ball with a cylinder if you are trying to clear both bumps (or clear even one bump) if this is what you are thinking about.

A simple surgical tubing pendulum kicker, pulled back by a 1.5" dia pneumatic cylinder (which is what we're using), can kick a ball quite far.