Pneumatic Catapult

I have decided to make a Pneumatic Catapult for my robot. I wanted to know how many Pistons (1 Reservoir) it would take to shoot a star from the starting tile over the fence. Or how many Pistons (2 Reservoirs)?

I don’t know if you can pull off a pneumatic catapult that can compete at a world level since you can get only so much actuations out of them.

Does anyone know approximately how many actuations can happen from one tank of air?

Regardless of how many pneumatic cylinders you will need, you’ll want two reservoirs. It’s difficult to calculate how many cylinders you will actually need (unless you really enjoy calculus) because of the “impulse” type of motion involved. This is a case for testing functional prototypes. I’d expect you’ll need to use 2-4 cylinders, and maybe some rubber-band assist, as well.

depending on how much pressure you set the regulator for, you can expect 20-40 strokes. A double-acting cylinder uses two strokes if you power it both ways. You can also use a double-acting cylinder like a single acting cylinder (saving air) if there is an external way to retract (or extend) the cylinder.

Oh, wow. That’s not very much at all. Yes, I definitely see why there would be very limited utility in using pneumatics - except for uses that didn’t require many cycles.

During the Skyrise season, many teams used pneumatics on their end-effector…but at the low-working pressure needed, they got plenty of strokes from their cylinders. So it is really a matter of how much working pressure is needed.