Possible pre-made piston

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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SpudUke5
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o ok i misunderstood.

Racket balls are pretty hard, so that would be a good ammo.
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THUNDERLORD
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@LikimysCrotchus5 : You didn't misunderstand.
I just naturally try to think of other possibilities.

But if Mcmaster's has a manufactured part that seals pressure, that would probably be the best choice to try.

BTW I remember an old safety add for safety glasses that said a racquetball on the court can have the striking pressure of a .22 cal. (rimfire bullet)!!!
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SpudUke5
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Im pissed right now!!!1 :evil:

[rant]
I as playing around with a 3 inch coupler and i put it in a 4 inch piece of pvc, and i noticed that for some reason, it fit PERFECTLY!! It slid beautifully.

Now the reason im pissed is that this piece could have been my piston, because my piston is a endcap and is not as reliable and also has a few rough spots when i push the piston in. Oh but wait, my piston is serviceable so i can make a new one put one in! No, i cant, why?

2 words pipe deformities.

So basically saying, that coupler fits very good into a 4 inch diameter piece of pipe, while this coupler doesnt fit the pipe that is already glued inside my tee. And they are the same company.
[/rant]

But anyway, im still not sure if im going to buy it because its kindof costly.
Instead, im going to make a mini version of this gun.
4SPC, My 4" piston 3" porting cannon
Memo:
Fix up copper cannon
Fix up 4SPC
Start Stirrup pump
Start Toolies piston bazooka
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Gippeto
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LikimysCrotchus5 wrote:
Gippeto wrote:... "true" to the bore of the tee ...
I dont quite understand that phrase that i just quoted.

OK, picture a flat top piston. Now replace the neoprene with peel and stick sandpaper.

With the barrel (or seat) solvent welded into the tee, insert this "sanding piston" into the tee.

Rotate the piston, putting light pressure on it. This will sand the end of the barrel "true" to the bore of the tee. (colour the end with a sharpie pen, and sand until the ink is gone)

This will compensate for any irregularities that were on the end of the barrel, as well as any alignment issues.

Your pistons will seal perfectly, first time, every time. :)
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keep_it_real
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2 words pipe deformities.

So basically saying, that coupler fits very good into a 4 inch diameter piece of pipe, while this coupler doesnt fit the pipe that is already glued inside my tee.
I think the pipe is actually a little smaller when it's squished into a fitting so thats probably why it doesn't fit. I've had the same problem before.
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biggsauce
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Nice technique Gippeto, I hadn't thought of that...

I'm lucky enought o have access to a chop saw, so true cuts aren't hard to get.

A little sandpaper by hand and I'm good
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JDP12
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yeap good idea gippeto thanks for that
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SpudUke5
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No it is pipe deformitites, (or something else) because i have a piece of unglued 4 inch pipe and the coupling doesnt fit in that, but in the other pipe it does.

Thats a good idea Gippeto, ill try that as soon as i have time.
4SPC, My 4" piston 3" porting cannon
Memo:
Fix up copper cannon
Fix up 4SPC
Start Stirrup pump
Start Toolies piston bazooka
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SpudFarm
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Galfisk used bouncy balls as piston a step back in time.
they performed horrible and shattered.
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biggsauce
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LikimysCrotchus5 wrote:No it is pipe deformitites, (or something else) because i have a piece of unglued 4 inch pipe and the coupling doesnt fit in that, but in the other pipe it does.

Thats a good idea Gippeto, ill try that as soon as i have time.
I made a coaxial with the same design (3" encap in 4" pipe) and all I had to do was a little sanding on the outside of the endcap and everything worked great
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SpudUke5
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I will experiment and see if i can get it to fit. I just need time not because ive been really busy.
4SPC, My 4" piston 3" porting cannon
Memo:
Fix up copper cannon
Fix up 4SPC
Start Stirrup pump
Start Toolies piston bazooka
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JDP12
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hmm well good luck
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