Air cannon help.

[quigly]

So I am drawing up idea for a future pneumatic cannon project, and came across an idea about threading in things and was looking for some insight on this.

So what the deal is that you need to put fittings(i.e. tapped in gauges and hoses, ect.) through 2 layers of sch40 right? But I figure I could get something like a coupler, cut it in half so you have 2 round pieces, then sand to make sure there is none of the inner rim blocking the pipe going through. Then properly prime it like normal, but then push it down the pipe until it would butt up against the end cap when it was place. Then you could spread your fittings out around a large area, and have more flexibility in placing filling hoses and the like. Would this make the pipe stronger to blowing the threads out, or would the bond not be correct, where it wouldn't reinforce it at all?

[Falcon7]

Depending on how you set it up, you should have plenty of space for your valves and whatnot. On mine, the psi gauge is threaded through two layers, but the fill and release valves are just going through one. Works just fine.

Build this:
http://www.instructables.com/id/The-Original-Potato-Cannon/#step1

Minus the bbq lighter, and add a twist valve from your hardware store or a push button one from http://www.spudtech.com/ to the barrel. Then you just add your gauges and valves. Unless you're looking to do an accurate replica or something, but this works very well.

[quigly]

I wanted to do two layer for every thing just as a precautionary. It will work, till it doesn't.

[quigly]

No one has any input on this?

[Sir Stubby Eyre]

Kind of hard to see what you are planning. Drawings would help. I don't know what tooling you have available. Research the type of pipe you want to use, some of the ABS is not the best for pressure vessels. If I was going to make another one I would use Schedule 80 PVC pipe. Do a lot of design work to begin with and then buy some parts to make your mock up, don't glue it all together tell you have it right. Post some more info so that I can see what direction you are going.

Hope this helps.

[DJ]

http://www.spudtech.com/

[quigly]

(sorry for size issue. Resize on photo bucket isn't working)

Basically just adding a ring to make it 2 layers to go through. Also, I know and am a big fan of spudtech. They have been bookmarked for a long while on my computer. I have all my designs down, I just need to know if doing this will in fact decrease thread tension. Also, I am planing on using sch40, as stated in first post.

[Falcon7]

Are my posts invisible?

[quigly]

I wanted to do two layer for every thing just as a precautionary. It will work, till it doesn't.

I replied to it.

[Sir Stubby Eyre]

Basically just adding a ring to make it 2 layers to go through. I have all my designs down, I just need to know if doing this will in fact decrease thread tension.

In a word, yes

[Variable]

Are my posts invisible?

They aren't invisible. The difference however is that the O.P. is looking to build an air powered cannon, not a traditional burning gas powered one.

[DJ]

Just out of curiosity, what are you planning on using for projectiles. I want to come up with something that will unleash a torrent of BB's at a range longer that AEGs will fire, say 150-200 yards.. Some kind of a sabot arrangement. True air soft artillery or mortar.....

[quigly]

I am planing on using a pocket vortex as a base. I will also make a mold of it, and cast some out of some different materials(i.e. varying weight polyurethane foam and rubber) to find if I can find something that can outperform the normal nerf. I also plan on trying to make different projectiles with different shapes.

I have thought about some kind of sabot round carrying BBs, but I cant think of some way to hold the BBs in a tighter pack when flying through the air. Rather like the old exploding shell used in the old 6 pounder cannons that would explode down range closer to the enemy. Of course I would use any explosive for this application.

[Icepick]

What about making a paper cup to hold the BBs in? I played around with PVC pneumatics for a bit and found that airsoft BBs are one thing that is going to be pretty annoying to make work... Use a circle for the base, and a cylindrical side. That way, the BBs would all be projecting from the same object at the same time, but the paper wouldn't actually be heavy enough to interfere with their flight path.

Just an idea...

[Falcon7]

Are my posts invisible?

They aren't invisible. The difference however is that the O.P. is looking to build an air powered cannon, not a traditional burning gas powered one.

That's what I was trying to explain. You can use the body of a combustion one and just add valves instead. Like so:



You just put the valves where the coupling intersects the body if you want them to go through two layers, no need to cut out extra pieces.

Definitely get one of these instead of the twist valve I have on there:
http://tinyurl.com/853sjy8

For sabots I use a piece of pvc pipe insulation cut in half then taped at the bottom, fits the barrel perfectly. As for filling it, you can carry around a bike pump, or you can get a paintball co2 or air tank plus the line from the gun that it attaches to and hook that up to a regulator then a schrader filler whatever-they're-called.