Some basic Pneumatic Design Questions

[DonRotolo]

Originally Posted by ttldomination

So, suppose a piston uses 1 cubic inch of air, and is fired thirty time. As per your math, it would be:

1 cu in * 30 actuations * (60 output psi / 120 psi) ~> 15 cu inches of "theoretical" storage?

Yes. That 15 in^3 would drop to zero if it remained at 120 PSI until the last actuation. In reality, it would drop about 4 PSI (1/30 * 120) each actuation, so after 15 actuations your storage pressure would be 60 PSI. You can do the math to see where you'll end up. Ryan's "double it" is reasonable.

Be sure to take into account all leaks, which can be non-trival. Also, storage is often not at 120, but a bit less.

An AndyMark AM-2478 ($15) is 30 in^3, weighs 0.56 pound, two of those puppies will keep you moving 1 in^3 well above 30 actuations. On the other hand, a 12" cylinder with a 2" bore would work maybe twice at full pressure.