amature air

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.
akadjusters
Recruit
Recruit
Posts: 2
Joined: Fri Oct 27, 2006 12:29 am

Fri Oct 27, 2006 12:51 am

Hi all, I've been a combustion fan for 5 years and have recenly built my 1st air powered cannon. Dwv was about all I could find. The dwv pipe is rated well within my limits @ 260 & 370 psi. Are the fittings the the supposed problem? They looked pretty dang sturdy to me. Also I'd like some feedback about a diagram I'm working on. My goal is to run the barrel down the middle of the 4" pressure chamber and use the valve internally. Anyone have a reason this won't work? You would have to modify the 2 bell reducers to allow the pipe to pass completely through them. I think it will be well worth the trouble. It would allow for a short powerful sleek gun, with only one obvious chamber.
Attachments
spud.png
spud.png
User avatar
SquishY
Specialist
Specialist
Posts: 155
Joined: Tue Feb 07, 2006 6:37 pm
Contact:

Fri Oct 27, 2006 1:10 am

What you are looking for is a Co-axial or a Diaphram, look them up in the Spud Wiki, a link is near the top right of the middle section of the site. Welcome to the world of Pneumatic guns, have a nice stay.
Whoever appeals to the law against his fellow man is either a fool or a coward.
Whoever cannot take care of themself without that law is both.
For a wounded man shall say to his assailant,
'If I live, I will kill you. If I die, You are forgiven.'
Such is the rule of honor.
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Fri Oct 27, 2006 9:27 am

This wont work because the air pressure is totaly surrounding your valve, no where for the pilot to empty, it will have equal pressure behind it so it wont open.
User avatar
singularity
Corporal 5
Corporal 5
Posts: 982
Joined: Mon Jun 26, 2006 10:53 pm
Location: someplace
Contact:

Fri Oct 27, 2006 11:10 am

i dont know about your valve but in all of mine the piolet emptied into the barrel, in this gun the barrel is un-pressurized (as one would expect). although the valves arent meant to operate in a pressurized envirornment i dont know if the pressure on the outside (as opposed to the inside) will affect its operation.
akadjusters
Recruit
Recruit
Posts: 2
Joined: Fri Oct 27, 2006 12:29 am

Fri Oct 27, 2006 3:48 pm

It's piloted out the blow gun through a fitting in the pressure chamber. I would probably move it to a reducer so it would pass through 2 layers of pvc.
User avatar
schmanman
Staff Sergeant 2
Staff Sergeant 2
Posts: 1685
Joined: Sat Mar 25, 2006 12:28 pm
Location: Michigan,U.S.A
Contact:

Fri Oct 27, 2006 4:05 pm

It's been done. should work. jrddw, that makes sense, but most diagrams I have seen of sprinkler valves show the pilot emptying into the barrel.
Persistence is a measure of faith in yourself
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Fri Oct 27, 2006 5:12 pm

Unless i missunderstand, the "pilot chamber" is the thing we are emptying so the piston moves back away from the barrel opening and allows the chambered air to excape out through the barrel, correct? There for, the "sprinkler valve" pilots the air from the "pilot chamber" out the back of the "sprinkler valve", correct? The blow gun, releases the air from the "sprinkler valve's" pilot chamber so that the "sprinkler valve" vents the cannons "pilot chamber", correct? So if the entire "sprinkler valve" is totaly surrounded by pressure there can't be a release because it's allready equal inside and outside, it won't do anything, it can't.
Yonderknight
Private 2
Private 2
Posts: 32
Joined: Thu Aug 17, 2006 7:16 pm

Fri Oct 27, 2006 8:04 pm

I don't think there is a piston. It's just a sprinkler valve used as the main valve to the barrel.
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Sat Oct 28, 2006 4:07 pm

Even though he's useing it for the main valve, you understand what i'm trying to say? I hope. Still wont work because of equal pressure all around, it has to have no pressure area to vent into.
User avatar
schmanman
Staff Sergeant 2
Staff Sergeant 2
Posts: 1685
Joined: Sat Mar 25, 2006 12:28 pm
Location: Michigan,U.S.A
Contact:

Sat Oct 28, 2006 4:41 pm

the pilot on sprinkler valves empty into the barrel, which is not pressurised, so It would work.
Persistence is a measure of faith in yourself
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Sat Oct 28, 2006 5:21 pm

The pilot still vents to the outside, not the barrel.
User avatar
schmanman
Staff Sergeant 2
Staff Sergeant 2
Posts: 1685
Joined: Sat Mar 25, 2006 12:28 pm
Location: Michigan,U.S.A
Contact:

Sat Oct 28, 2006 5:37 pm

wait, i'm confused. :?
Persistence is a measure of faith in yourself
User avatar
singularity
Corporal 5
Corporal 5
Posts: 982
Joined: Mon Jun 26, 2006 10:53 pm
Location: someplace
Contact:

Sat Oct 28, 2006 8:16 pm

the pilot valve in a UN-MODDED valve emptys into the barrel this is a MODDED valve so it emptys from the blowgun which in the pictures provided is clearly outside the gun, meaning it will work just fine
be sure to check out my <a href="http://www.spudfiles.com/forums/ak-styl ... 9.html">AK Styled Vortex Gun</a> and my <a href="http://www.spudfiles.com/forums/at-4-t9627.html">AT-4 Rocket</a>

upcoming projects... finalized clip fed BBMG and ball point pen sniper
User avatar
schmanman
Staff Sergeant 2
Staff Sergeant 2
Posts: 1685
Joined: Sat Mar 25, 2006 12:28 pm
Location: Michigan,U.S.A
Contact:

Sat Oct 28, 2006 8:19 pm

my stupid computer wont show the pics, only the laptop will, and my dad is using it. so, I couldn't tell from the pics (cause' I couldn't' see them) or the description that it was modded.
Persistence is a measure of faith in yourself
Post Reply