This instructable is an air cannon that fires nerf pocket footballs at 145psi up to 450 yards. For is simplicity i think this is one of the best high powered air cannons on instuctables. If your wondering why i didn't usea sprinkler valve its because it doesnt release the volume of air a ball valve does and i didn't feel like spending $60 on a 2 inch sprinkler valve. All the pipe i used was pressure rated to 250 psi and up. The valve being the acception it was rated to 165 psi. I am making a pnuematic ram to turn the ball valve very quickly.
Step 1: Collect What You Need
To start buy the following as seen in the image below.
Step 2: Dry Fit Your Cannon
dry fit your cannon to make sure everything fits together right, as in the image below. The wooden thing in between the barrel and the chamber is a spacer I cut out with a zipsaw to keep the barrel and the chamber apart. I put on a large hose clamp later
Step 3: Glue Together
Glue the assembly together using pvc glue be sure to prime it with pvc primer do not use abs glue or other types of glue they will not hold it together as well as pvc glue will and may fail. I use oatey rain or shine it works very well.
Step 4: Now Fire!!!!!!
At 145 psi this will go 1/4 of a mile or more. I fire nerf pocket footballs as seen below the 2 inch barrel also fits billiard balls perfectly but those are more dangerous so be careful. you may have to cut the wings ends a little bit to fit it in the barrel but once you fire it, it will fly out of sight very quickly. at only 35 psi I have gotten distances of 250 yards.
Be careful this is not a toy I am not responsible for any idiot who overpressurises it and kills or seriously injures themselves or others or damages property by using it in the wrong place or at the wrong time.