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.
-
jitup
- Specialist 2

- Posts: 251
- Joined: Wed Nov 12, 2008 1:40 pm
- Location: North east Ohio
Wed Dec 31, 2008 2:49 pm
Hello these are my plans for a semi auto. It will shoot power popper rounds, since I am not allowed to shoot marbles. (my parents are worried about the effects that marbles can have on windows if picked up by a lwan mower)
The benifit of these is that they form a perfect seal in 1 inch pvc. also If I shoot them at a low pressure (20-40psi) I can cap my frineds with them, and they can return the favor. ( we are building our own guns to skrimish with, they just use my designs and make me go to the hardware store to help gather parts) I was planning on using regulated CO2 from a paintball Co2 tank and using a quick connect. if I chose to fire at a hirer psi at targest the max I would take it to is 120-160 psi. Is this safe? I have read many mixed opinions about using co2 with pvc. I will use a remote coil to a vertical tank, so all the Co2 should be in gas form by the time it reaches the gun. Let me know what you think her are some drawings of the valve and the overall gun. The barrel will have a 1 to 1 ratio in reality. the pics are not proportionate.
-
Attachments
-

- Should I use a spring instead of a rubber bumper?
- semi auto valve.JPG (20.99 KiB) Viewed 3196 times
-

- here is the overall lay out
- semi auto.JPG (11.49 KiB) Viewed 3196 times
-
Hubb
- First Sergeant 2

- Posts: 2390
- Joined: Mon May 28, 2007 8:39 am
- Location: South Georgia
-
Contact:
Wed Dec 31, 2008 2:55 pm
About CO2. If you have a good regulator, you should not have to worry about liquid getting into the chamber. With that said, search the web for a Palmer's Stabilizer.
Another thing to look for is one that will operate at low pressures. Considering CO2 runs anywhere between 800 to 900 psi, 100 psi is low pressure. The Stabilizer will do this.
Other than that, I can't really give too much more input, as I don't really understand your design.
-
jitup
- Specialist 2

- Posts: 251
- Joined: Wed Nov 12, 2008 1:40 pm
- Location: North east Ohio
Wed Dec 31, 2008 2:57 pm
yes, this is a variation of one of Clides valves. (sorry clide I forgot to add that in the original post) and I have an Evil detinator, which will do the same job as the palmer (just a little cheaper) Will this setup work for semi auto shooting?
-
frankrede
- Sergeant Major 2

- Posts: 3220
- Joined: Thu Jul 20, 2006 9:47 pm
- Has thanked: 1 time
- Been thanked: 1 time
Wed Dec 31, 2008 3:55 pm
Your making this way overcomplicated.
You could do this with a sprinkler or a QEV easily.
What you need to work on now is the semi-auto feeder. I suggest a paddle type interrupter.
Current project: Afghanistan deployment
-
littlebro05
- Specialist 4

- Posts: 418
- Joined: Wed Oct 17, 2007 5:04 am
- Been thanked: 1 time
Wed Dec 31, 2008 4:47 pm
Dude, I wish I had friends like yours

... Because all of my friends are too lazy to the extent that I would have to go buy the parts... make it and then they pay me

at least you friends can build stuff with you designs... cloud BBMGs are so easy to make but they're plainly too lazy... damn you consumerism.
It's Nerf or Nothing.
Don't start crying when I play this as my hobby, Paintball, Airsoft and Nerf are equally good hobbies, except you can play Nerf in public. Good day! Hmph!
-
jitup
- Specialist 2

- Posts: 251
- Joined: Wed Nov 12, 2008 1:40 pm
- Location: North east Ohio
Wed Dec 31, 2008 5:58 pm
I do not want a commercial valve because they are not redily available in my area. also I enjoy making the valves. I am goint to use the second T in the pic with a length of pipe glued in as the mag. it will hold 12 or 24 shots (haven't decided yet) it will employ a shotgun spring glued to a washer to push the balls up. also the cap at the bottom will be a screw on.
EDIT
Frankrede can you pleas elaborate on how your idea for the feed system would work?
-
jackssmirkingrevenge
- Five Star General

- Posts: 26216
- Joined: Thu Mar 15, 2007 11:28 pm
- Has thanked: 576 times
- Been thanked: 347 times
Thu Jan 01, 2009 1:07 pm
A piston with an angled face is a bad idea, as soon as it rotates a little you're screwed. I would make a QEV type valve, small flow if you're going to use it for skirmishing as you don't need a lot of power and you'll get more shots per tank.
As to the "paddle" type system, have a look at mark's
full auto marble gun.
-
jitup
- Specialist 2

- Posts: 251
- Joined: Wed Nov 12, 2008 1:40 pm
- Location: North east Ohio
Sat Jan 03, 2009 3:48 pm
thanks for the word of warning JSR, but I really want to see how this type of valve will work. What is a QEV style piston (maybe I will build that) is it a normal T piston valve?
-
jackssmirkingrevenge
- Five Star General

- Posts: 26216
- Joined: Thu Mar 15, 2007 11:28 pm
- Has thanked: 576 times
- Been thanked: 347 times
Sat Jan 03, 2009 3:52 pm
A QEV style piston is pretty much a tee valve, and I would definitely put a spring behind the piston to help it reseat after firing otherwise you'll lose all your air after one shot.
-
jitup
- Specialist 2

- Posts: 251
- Joined: Wed Nov 12, 2008 1:40 pm
- Location: North east Ohio
Sat Jan 03, 2009 4:03 pm
The chamber will be pretty small, and is meant to lose all it air after each shot, than refill. I am making it fully maintanible. If I am not impreesed with the performance, I can tweak and experiment. BTW, I can't find a spring the size I need, any idea how to make them???

-
jitup
- Specialist 2

- Posts: 251
- Joined: Wed Nov 12, 2008 1:40 pm
- Location: North east Ohio
Sat Jan 03, 2009 4:21 pm
Thanks for the info! I think I will keep looking for the right size compression spring, maybe I can trim one. seems like a hassle if you don't have acess to a lathe.