Thanks for the info! I had wondered about the barrel being to long and actually slowing down our projectile but I figured that because we had such a large pressure chamber with a lot of air behind it, it would be okay. I have gotten a hold of a chronograph so we can measure the muzzle velocity of th...

Update: Had our first test fire today, turned out awesome. The first shot -- with about 30ish psi and only 10 feet of barrel attached -- launched....well I don't know because we couldn't find it. It landed in the middle of a muddy corn field and we will need to look tomorrow for it. The second one l...

Thanks for the input, I did do exactly that. Seems to work great. Had a small leak at 60psi from the front coupling and reducer, but i took care of that. I think we may be testing today! I'll let you know how it holds up at 80psi and how far we can launch the potato! In 2009 a class built one like o...

What if I were to drill a hole, cut threads into the hold with a tap, then screw the 1/4 quick disconnect into the hole and cement it in place?

Wow this is ambitious, thats all i have to say. I dont even know why you need a fan lol. More of a hairspray and fire kinda guy.

Hahaha yes we have quite a large air compressor, something like a 50 gallon compressor. I am not very inclined to these sort of things though. We do have a ball valve that we plan to use to release the pressure from the tank to the barrel. With the 1/4 inch npt how would we attach it to our tank?

Are caps not a good way to seal a pressure chamber? What if the cap and pipe are sch 40?

Do you have any pictures of this? I would like to see your progress.

So my physics class is building a potato cannon as a project and I need some advice and help. We have all of the pieces now and all we need to do is put together our air chamber and we are ready to go. Before we cement the pvc in place i was wondering where the best place is to put our schrader valv...