Pneumatic Launcher Question

My team is wanting to make a big ball launcher out of two double acting pistons (one reservoir) and we are wandering what psi we should fill the reservoir up to. Also does anywhere know where I can get a fairly inexpensive air pump? Thanks

The maximum legal air pressure for VRC is 100 psi. I’m not sure for TSA Vex, but I assume it’s the same.

There is a max psi for toss up?

Never mind just found the rule

Does anyone know of good cheap pumps to buy?

Your local Target/Wal-Mart/etc. should have a cheap one.