Piston Valves Explained Visually

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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cowscankill
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Sat May 21, 2011 12:02 am

I use a blowgun trigger for my 1" coaxial piston. I can't find much on equalization properties and what I might be doing wrong? I did figure that a pilot valve could be the problem, but after seeing many designs, I thought a blowgun trigger would work.
I appreciate the help guys.
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Crna Legija
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Sat May 21, 2011 12:12 am

clean off all the grease on the piston and put a layer or two of tape on it. then try if it still don't work try a bigger pilot valve.
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
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Hubb
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Sat May 21, 2011 1:44 am

The "equalization hole" on a standard piston is the gap present between the piston and the valve walls. A lot of times, this is too large, but not visible to the naked eye. Crna Legija has suggested what many have done to great success. Try the tape before changing the pilot valve.
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cowscankill
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Sat May 21, 2011 5:57 pm

Thanks for the advice! I put an o-ring on my piston to seal it better, and it does. I actually get some air to come out of the barrel.
But now, however, most of the air still comes out of the trigger and only a portion of the air comes out of the barrel. At 100 psi, it doesn't really seem to do much. Any more suggestions?
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Crna Legija
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Sat May 21, 2011 9:53 pm

what are you using as a pilot and for how big of a piston valve?
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
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cowscankill
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Sat May 21, 2011 9:58 pm

Ha, already said that, it's a 1" piston valve made of resin with an O-ring and rubber sealing face. The pilot is a blowgun trigger. All I can assume is that the piston is inefficient, and that's why a lot of air comes out of the trigger.
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Crna Legija
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Sat May 21, 2011 10:02 pm

try with a 1/4-1/2 ball valve as pilot
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
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cowscankill
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Mon May 30, 2011 12:42 am

Made a prototype for my real air gun. This one doesn't need a new thread.. I don't think it's worthy. I'll post the official gun eventually, I still need money.
Image
I even compiled a quick demo vid.
http://www.youtube.com/watch?v=TCaxm1fkYHs
Thanks for the help guys, turns out I had the exact problems you guys mentioned haha.
Peace out, I'll be back with better stuff later.
jonathansu_
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Tue Jun 12, 2012 1:42 am

now i understand how it works! thanks :D
mr.potatohead
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Sun Jul 15, 2012 3:00 pm

does the piston go back to its starting point when all the air is relesed
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mattyzip77
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Sun Jul 15, 2012 3:49 pm

No it goes on vacation for a week lol. Of course it does
Go Bruins!!!!
mr.potatohead
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Sun Jul 15, 2012 6:53 pm

mattyzip77 wrote:No it goes on vacation for a week lol. Of course it does
i meant does it stay back or does it shoot forward
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mattyzip77
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Sun Jul 15, 2012 8:21 pm

It returns to its original state unless its set up.for semi auto then it will just keep repeating the process
Go Bruins!!!!
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Crna Legija
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Mon Jul 16, 2012 2:59 am

mr.potatohead wrote:i meant does it stay back or does it shoot forward
no, you need to add a spring behind it if you want it to do that but its useless unless you want to chamber fill.
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
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archie370
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Tue Sep 04, 2012 10:53 pm

This looks good but by looking at your diagram i cant seem to follow your magazine chamber to your barrel it seems that the ammunition gets caught on the blow back part of the rifle ... ? could you explain cuz i suck at this :) ?
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