3 In. Piston Valve Launcher

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.
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Mon Dec 03, 2012 3:34 pm

This is my first piston valve gun. It has two 5 ft long air tanks, 3 in. diameter. The piston housing is 3 in. with a 2 in. barrel. Soon to come: golf ball barrel! I'll see if I can get some videos later.

The only issue I have with it is that sometimes my pilot release valve doesn't bring the piston back. I believe it's because it's either too small or too tight. I really don't know enough about them to tell. I've messed around with wrapping layers of tape around the back of the piston (ghetto, I know) for a tighter fit but it's too hard to tell exactly what the problem is. Maybe somebody could help? :)

Note: The broken cinder block is from me trying to pick it up. I made about one and a half steps until it basically crumbled. Luckily, none smashed my foot :D I know the video of the prior shot looks unimpressive, but one more psi and the thing wouldve been shattered

[youtube][/youtube]
[youtube][/youtube]
[youtube][/youtube]
[youtube][/youtube]
[youtube][/youtube]
[youtube][/youtube]
Attachments
from the back
from the back
from the side
from the side
my piston
my piston
looking down the barrel
looking down the barrel
my bumper
my bumper
my modified solenoid pilot exhaust valve
my modified solenoid pilot exhaust valve
Last edited by jrrdw on Thu Oct 24, 2013 11:56 am, edited 9 times in total.
Reason: Fixed videos.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Mon Dec 03, 2012 4:04 pm

Nice first effort :) a ghetto piston like that needs a good pilot though, what are you using? A sprinkler valve would be an adequate solution.
hectmarr wrote:You have to make many weapons, because this field is long and short life
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Mon Dec 03, 2012 4:05 pm

yeah i'm using a sprinkler but for some reason it doesnt seem like it's opeing all the way. If i can get this darn video uploaded, maybe you could see. It almost whistles for a second or two before firing

There i posted the video
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Mon Dec 03, 2012 4:23 pm

The yellow coiled line is screwing you over by dramatically increasing the sprinkler pilot volume. You need to mount the sprinkler pilot on the valve itself.
hectmarr wrote:You have to make many weapons, because this field is long and short life
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Mon Dec 03, 2012 4:24 pm

alright, ill give it a try!
User avatar
mattyzip77
Sergeant 3
Sergeant 3
United States of America
Posts: 1249
Joined: Tue Jun 28, 2011 12:22 pm
Location: Taxachusetts

Donating Members

Mon Dec 03, 2012 10:24 pm

Nice gun too much pilot volume.... I would also try using a we've for a pilot..
Go Bruins!!!!
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Mon Dec 03, 2012 10:36 pm

A we've?

I'm uploading another video to youtube now of a better shot.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Tue Dec 04, 2012 1:47 am

QEV autocorrect? :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
8tonsemi
Specialist 3
Specialist 3
Posts: 321
Joined: Thu Feb 16, 2012 6:08 pm
Location: The moon

Tue Dec 04, 2012 2:32 pm

I personally wouldn't use this gun because of all the dwv on it, it's going to explode sooner or later. Nice job besides that just make sure to use NSF-pw fittings next time.
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Tue Dec 04, 2012 6:43 pm

All the parts are pressure rated. I made sure. I bought and glued dwv elbows that weren't pressure rated so I had to throw them away. I double checked all parts after that. They're safe, I promise. I wouldn't use it otherwise.
User avatar
mattyzip77
Sergeant 3
Sergeant 3
United States of America
Posts: 1249
Joined: Tue Jun 28, 2011 12:22 pm
Location: Taxachusetts

Donating Members

Wed Dec 05, 2012 9:55 pm

Thank u jack!!! :D Listen to 8ton.. I wouldnt bring that thing past 40 or 50 psi or your going to get a piece of pvc embedded into you for sure due to the drain waste vent fittings..
Go Bruins!!!!
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Thu Dec 06, 2012 12:12 pm

None of them are dwv. My uncle's friend works in a lab that has access to pressure rated fittings that usually aren't. I'd show you pictures but my primer got all over where it says. The lowest rated part is the blowgun with a max of 90 psi
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Thu Dec 06, 2012 2:50 pm

The sockets look quite deep so I suspect acs2997 is correct and he is just using the DWV-style pressure rated fittings.

If it has NSF-PW on the fittings, they'll be pressure rated.
acs2997
Private 4
Private 4
Posts: 62
Joined: Wed Jul 04, 2012 10:36 pm

Thu Dec 06, 2012 6:28 pm

Trust me, I wouldn't be using it if my life was at risk.
Post Reply