Valve trouble:

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.
User avatar
DonTheLegend
Private 4
Private 4
Posts: 99
Joined: Fri Jan 06, 2006 6:32 pm

Tue Jun 17, 2008 1:03 pm

Glad i could help
microman171
Specialist
Specialist
Posts: 189
Joined: Wed Apr 30, 2008 11:49 pm

Wed Jun 18, 2008 12:06 am

judgment_arms wrote:
microman171 wrote:I am thinking of making a gun just like this and I was wondering how the barral on this works? I cant actually see it...
Well, that’s probably because there is no barrel on it yet. ;)
The barrel attaches to the side with the 1” female adapter, in the picture entitled “Valve Body” it’s the right hand side.
'


Ah cool thanks. I am deciding between this and a diaphragm housed in a union
biged
Private 4
Private 4
Posts: 99
Joined: Sat Jun 09, 2007 8:06 am
Been thanked: 1 time

Wed Jun 18, 2008 5:47 am

Guide washer:
When you cut that cross in the guide fender washer the face of the piston now has a lot of play - leaking piston face. Drill a series of holes in another fender washer and leave the outside diameter intact. This will center the piston face better on the port.

Port washer:
I use a fender washer about 1/16th of an inch smaller in diameter than the porting size. It functions in two ways.

1. Acts as a guide and helps to center the piston face into the port.
2. Retains the gasket in place and prevents it from being blown out the port.

To make a fender washer slightly smaller you need a bench grinder.
Put the fender washer on a scrap piece of rod and grind off material. The washer will spin fast so wear safety gloves and glasses.

Pilot seal:
To increase pilot seal. Over tighten the nuts on the pilot washer. This will crush the rubber and increase the outside diameter of the piston. Use white lithium grease on the gaskets. It should be tight when pushing it in.

Piston face gasket
Source thicker rubber gasket material. I use rubber roofing guard. It's 1/8th to 3/16th on an inch thick, some companies carry the 1/4 thick. Contact your local roofing company and inquire about some scrap pieces to make a thick rubber gasket.

///ed///
User avatar
judgment_arms
Sergeant 3
Sergeant 3
Posts: 1272
Joined: Tue Oct 17, 2006 8:49 pm
Location: Not so beautiful North Carolina, but at least it’s the U.S.A.!

Wed Jun 18, 2008 9:00 am

biged wrote: Guide washer:
When you cut that cross in the guide fender washer the face of the piston now has a lot of play - leaking piston face. Drill a series of holes in another fender washer and leave the outside diameter intact. This will center the piston face better on the port.
That was the original plan, but I thought that filing the notches would give more flow.
Port washer:
I use a fender washer about 1/16th of an inch smaller in diameter than the porting size. It functions in two ways.

1. Acts as a guide and helps to center the piston face into the port.
2. Retains the gasket in place and prevents it from being blown out the port.

To make a fender washer slightly smaller you need a bench grinder.
Put the fender washer on a scrap piece of rod and grind off material. The washer will spin fast so wear safety gloves and glasses.
My plan was to chuck it in the drill press; I would have thought that using a grinder would leave it rough and uneven
Pilot seal:
To increase pilot seal. Over tighten the nuts on the pilot washer. This will crush the rubber and increase the outside diameter of the piston. Use white lithium grease on the gaskets. It should be tight when pushing it in.
If I tighten it to much the air can’t get by it to fill the chamber.
Everybody says white lithium grease is the best, but I find mineral oil to work great, and it doesn’t leave any sticky residue.
Piston face gasket
Source thicker rubber gasket material. I use rubber roofing guard. It's 1/8th to 3/16th on an inch thick, some companies carry the 1/4 thick. Contact your local roofing company and inquire about some scrap pieces to make a thick rubber gasket.
I got gasket material, I ain’t got a piece handy, but I’m pretty sure it’s about 1/8th inch think.
I’ll have to head to Agri Supply, they’ve got dang near every thing, maybe they’ll have some thicker rubber.


Thanks! :)
Call me "Judge", it's easier to type.

Spud gun safety rules
Post Reply