4" Piston Cannon pls

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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benstern
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NO!!!!!
It is NEVER ok to use abs on a pneumatic. EVER!
cwazy1
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elaborate
just saying no does not mean anything.
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Hubb
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ABS, like DWV, is not pressure rated. NSF-PW pipe is designed to take pressure, but the other two are not. This is not saying that they will not hold pressure, it's just saying that these have not been tested (by the NSF).
cwazy1
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^^^ exactly, but why must we wait for the "NSF" to test it?
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Hubb
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You don't. You can go ahead and use it. It's just not recommended. Besides, there is a such thing as pressure rated ABS.
cwazy1
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yeah tahts true, there is, its just hard to come by. same with solid wall abs.
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MrCrowley
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Most combustions only produce 30-40psi.

Anyway I've had 260psi rated PVC blow at 110psi, so i'm not going to tell you not to use it, you know what you are doing so do what you want.
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Hubb
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To be honest, I try to avoid non-pressure rated parts / pipes for all my cannons (besides, of course, the occasional cleanout for a combustion).
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jrrdw
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I was thinking wow, the first snub nose coaxle. But wait, it doesn't even have a snub on it, it's the first flush nose??? Any video's of it in action? I'de like to see it launch a golf ball through something.
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psycix
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Yeah could we have more pics and maybe a vid of it?
How does it perform?

And some guys should stop whining about the ABS, if he wants to use that, let him do. Okay, he could better have invested in PVC and use it up to 100PSI but so what?
Hes not taking it over 60PSI, wich means hes using it SAFE and secondly, IF it should blow, its ABS and not PVC so he'll lose only a couple of bucks and no health.

Great cannon, though i reccomend a longer barrel.
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dewey-1
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Last edited by dewey-1 on Sun Apr 20, 2008 3:16 pm, edited 1 time in total.
cwazy1
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haha yeah its cut perfectly flush, the damage this thing can do is pretty impressive, it can eat through 1" plywood with a clean hole and can go through 1.5" with a not so clean hole. the only bad thing about this gun is that its literally impossible to aim, when you open the valve, the whole cannon moves about 2" to the right and because of the motion of opening the valve and the whole cannon itself is only 20" long, it causes the projectory of the GB to be off by alot. after fireing it a while you learn to adjust (like a sniper..refering to the topic about sniper scope clicks..lol)

all the shots are done at around 55-60psi. i want to pump up the psi and try it at say, , 80, but cuz its abs, i am hesitant to try and its cold. so im sticking with 60..lol

i dont have any videos but i can get some damage pics. i'll post them by tomrw.

yeah see i was really debating on whether i should cut it flush or leave 2' of barrel outside the chamber, but i decided that since having a barrel outside of the chamber, would look too much like a simple combustion(linear noob hairspray gun). thus i cut the barrel flush and now it looks like "the tube of death" i just love how clean it is, literally a 4" pipe section with a valve and a gauge on the other side. no one would guess it shoots stuff.
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DYI
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While I don't particularly like the use of parts rated for 10 psi on a cannon that operates at 60 psi, I would have to say that Benstern is DEAD WRONG (as usual, I might add). It is always OK to use ABS on a low pressure pneumatic, because you can't really do any more than damage your hearing if it fails. A PVC pneumatic on the other hand... If this is cellular core ABS though, you should scrap it. Exploding ABS is an unfortunate loss of money, while exploding PVC has a great potential for severe injury.

As a safety precaution, never place any part of your body behind the cleanout cap while it is pressurised. I've had a nasty experience with that before. Keep it below 60 psi, and you should be fine. Unrated ABS is always better than unrated PVC, but rated pipe is preferred. Comparing rated PVC to unrated ABS is kind of pointless.

How people have generated such skewed stereotypes against ABS I have no idea.
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Looks pretty good, I really like the compactness.

And you should be fine at about 60 psi, and like you said if it gives it'll rip instead of fragging. I would recommend chucking that clean out and replacing it with a plug (though that would run you some more cash) just because those are probably the weaker of the dwv fittings. Then again it's 60 psi, and I've taken clean outs to 125 psi with no problems.
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cwazy1
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yeah i was debating the plug/cleanout stuff..the only reason i chose the cheapout was cuz if i had a plug there, i wouldnt be able to service my piston
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