I dont know if many people can help but if started building a pneumatic cannon and cant find what sort of rubber to use for the diaphragm. Any one know what to use and where to get it and stuff?

Have you ever seen the rescue bags used to raise up collapsed roadways etc...I don't know exactly what your application ensues, but the bags are capable of containing extreme pressures...lots of psi! If one of these bags were linked to a large selanoid you could propell just about anything...

i havent seen one before

Do think a tractor trailer inner tube would work? It would require some modifications.

I hear dish drainer mats are the ISO standard diaphragm. I use solenoid valves instead, though, since they're premade and I rarely need the amount of flow that a diaphragm would give me. All of my cannons fire golfballs or smaller.

~Zero the Inestimable

What about an "air ride" system from a tractor trailor?

Just a thought.

i wanna make a diaphram one cus they are simple and cheap. i wanna lob potatos over places ( and on halloween eggs). en egg wouldnt work so i would have to give it some sort of pressure armor

Static, Sorry, I think I should change my name to "overkill". Those rescue pressure bags I mentioned earlier are capable of lifting a four story building. The same technologies are being used in japan for earthquake resistance. Look up "matjak".

I don't think eggs will survive the trip down the barrel.

shit i could lob a block a cement accross the ocean with that. yeah i dont think an egg will work but i wish it wood