My little diaphragm gun

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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noname
First Sergeant 4
First Sergeant 4
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Joined: Mon Apr 10, 2006 9:19 pm
Location: Bay Area, CA

Sun Feb 18, 2007 11:39 am

Seeing tylerthetatertosser's gun reminded me of this, and that I hadn''t posted it yet. It's been sitting around in my garge since September or something.
It uses a diaphragm valve inside a 1 1/4" T, and is piloted by a blowgun. It has 3 barrels, 1/2" Sch 80 for AA batteries, 1/2" Sch 40 for other 1/2" stuff, and 1/2" SDR 13.5 for paintballs and marbles. The paintjob is weird, I know, you don't need to point it out. It's also kinda crappy, 1 coat.

I deleted old camera software, so now can resize and upload them!
Attachments
The back of the diaphragm valve. Yes, some paint got in there, oh well, it's the front that matters.
The back of the diaphragm valve. Yes, some paint got in there, oh well, it's the front that matters.
The whole gun, except for the pilot, which was cut off by the picture.
The whole gun, except for the pilot, which was cut off by the picture.
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ProfessorAmadeus
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Sun Feb 18, 2007 1:09 pm

Cool! Whats is the diaphragm made out of? I see that you conected the valve it self to the chamber with some type of fittings but what exactly are they? Im guessing male and female adapters but i cant quite see it clear enough to tell.

Did the diaphragm need ans equalization hole? Did you lathe down that back bushing in the first picture?
Insomniac wrote:Hey why am I a goose???? Why not somthing a little more awe inspireing, like an eagle or something? LOL
SOO CUTE!! OMG!! I COULD JUST LICK YOU!!
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noname
First Sergeant 4
First Sergeant 4
Posts: 2698
Joined: Mon Apr 10, 2006 9:19 pm
Location: Bay Area, CA

Sun Feb 18, 2007 2:18 pm

The diaphragm is 1/16" thick neoprene sheet.
The valve has 1" porting connected to the chamber (1" female coupler cut in half to make it cleaner), then a 1" steel nipple, then 1" female threads again. I wanted the valve to be removable.
Homemade diaphragms never need equalization holes, because air will always leak around the sides, no matter how tight of a fit it is. And I've already answered the last question.
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