new piston gun now with damage pics

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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super spuder
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Sat May 12, 2007 7:28 pm

noname wrote:You'd need an equilization hole because air will fill the chamber and push the piston; no air will get to the exhaust area unless you have 2 fill valves, which you don't.
i actually do. i am not as dumb as you may think. oh, crap, i forgot to show a picture of that.
trying to decide on a new project, probably something small.
keep_it_real
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Sat May 12, 2007 7:29 pm

With the modded blowgun. I don't know how much flow a modded blowgun has though.
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super spuder
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Sat May 12, 2007 7:34 pm

ok, this is how it works, the moded blow valve fills the area behind the piston. Then i take the air hose off that and put it on the Quick coupler on the other side of the piston, fill that up, then pull the trigger on the blow valve and the piston comes back ,lets all the air out the chamber and into the barrel thus sending a projectile off into the distance :D and duck tape does seal
Image
that is the second fill valve that i don't really have :lol: next time, ask me if i have one ensted of accusing me that i don't.
trying to decide on a new project, probably something small.
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noname
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Sat May 12, 2007 9:00 pm

Is the equilization hole drilled right through the bolt?
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homedepotpro
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Sat May 12, 2007 9:03 pm

hey is there anyway of getting a video of the gun firing?
or a shot of water shooting out the barrel
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super spuder
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Sat May 12, 2007 9:06 pm

there is no equalization hole. i fill the chamber with the quick coupler and the part behind the piston with the blow valve, no need for equalization hole. :)
trying to decide on a new project, probably something small.
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noname
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Sat May 12, 2007 9:09 pm

Oh, you're "I actually do" statement at the top of this page lead me to believe you had one, instead of the two fill valves you have.
You're still not going to get me to believe the duct tape seals the piston.
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super spuder
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Sat May 12, 2007 9:11 pm

well when i shoot it i will take a video of it to show you that it seals, probly tomoro.
trying to decide on a new project, probably something small.
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noname
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Sat May 12, 2007 9:14 pm

Show me a picture of a presure guage attached without the pressure dropping and I'll believe it.
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super spuder
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Sat May 12, 2007 9:32 pm

noname wrote:Show me a picture of a presure guage attached without the pressure dropping and I'll believe it.
hmmmm, i don't have a pressure gauge right now, i will see if i can get one, where do you want to see the pressure gauge on the gun and not dropping, behind the piston by the blow valve or on the main chamber?
trying to decide on a new project, probably something small.
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hi
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Sat May 12, 2007 9:34 pm

the chamber would be nice, then it wouldnt get slamed into with a piston.......
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
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super spuder
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Sat May 12, 2007 9:38 pm

ha ha ha, yea, i could just thread it in where the blow valve is, or should i say was :lol: . i went out and tried it tonight and blew the blow valve out at 30 psi. So i have to go and get a threaded adapter tomorrow

edit:@homedepotpro, i can not shoot water out of this gun :( all the water would run in between the two pistons and then it would not actuate
trying to decide on a new project, probably something small.
rad14701
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Sun May 13, 2007 9:49 am

If the piston valve is actually two separate pistons I'm doubtful that you will get much pressure into the main chamber before the cannon fires without some form of equalization... My guess is that you'll have more premature launches than not... The simplest way to achieve equalization would be to use an external equalization tube between the two chambers and then experiment with the size of the bleeder hole... There is a picture somewhere here in the forums or Wiki that shows an example of this technique... This way you will actually be able to rely on piloting manually to launch...
keep_it_real
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Sun May 13, 2007 10:00 am

Get a presta valve and glue it inside some vinyl tubing and use that as your equalization hole like rad14701 said. A presta valve works like a check valve so you won't have to do any bleeder hole experimenting and it will be more efficient. Schrader valves don't work the same way so you'll need a presta valve.
rad14701
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Sun May 13, 2007 10:06 am

keep_it_real, are you implying using the presta valve for both equalization and as a check valve...??? That would definitely be better than playing with bleeder sizes...
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