[Andrew Blair]

No white paper that I know of, but it's quite simple.

1. Buy ~ 3" pressure rated schedule 40 PVC pipe, depending on what diameter barrel you want. 3" works well for t-shirts and small foam balls. You'll be using this for both the barrel and tank.

2. Buy an irrigation valve with large diameter bore. (Ours is a 3/4" throat, 24 volt irrigation valve from Lowes. It ran about $17 and has worked perfectly. It's just a simple solenoid, so 12 volts works fine with it)

3. Buy appropriate end caps, fittings, tubing, and good, relatively high pressure PVC glue (It'll tell you it's best rating on the can. Ours is a tan glue)

4. Put it together.

It's not much of a how to, but it'll get you started. Um, one thing concerning the PVC air tank- conversation recently generally agrees that even pressure rated pipe has a serious possibility of catastrophic failure, so be careful if using our setup. We are considering adding some shielding or containment devices around the tank just in case. Even better, use an actual air tank. But it's important to have all openings be at least the size of the valve gate, otherwise you'll bottleneck.

As for the barrel, just start with a long length, and test it, shortening the barrel until you get good results. Different projectiles will like different lengths.

Have fun, ours never seems to get old, and the community really likes it, so it's really a good investment! Any more questions you have I'd be happy to answer.