My First Pneumatic

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.
Juicey
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Sun Apr 29, 2007 10:57 am

Lol I love the destruction of the lawn ornament. And wasn't there a gun posted on here a while back that had a smaller chamber attached to his gun which operated a piston to open the ball valve? I can't seem to find it atm. But that would seem to be the holy grail when it comes to opening ball valves.
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noname
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Sun Apr 29, 2007 11:03 am

It's all metal, the pump will blow before the gun does. I'd use as much pressure as possible (until I can't pump or the pump's guage is maxed out or over.).
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jackssmirkingrevenge
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Sun Apr 29, 2007 11:05 am

noname wrote:It's all metal, the pump will blow before the gun does. I'd use as much pressure as possible (until I can't pump or the pump's guage is maxed out or over.).
Looks like plastic to me, I don't think that would be a very good idea... hence my suggestion re the sprinkler valve :wink:

Edit: wannabie, have a look here for some inspiration for incorporating a "proper' trigger into your design.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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homedepotpro
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Sun Apr 29, 2007 1:25 pm

hey i was just at he sport store looking at those sling shot bbs, do they work well.

what size is the barrel?
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jackssmirkingrevenge
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Sun Apr 29, 2007 9:53 pm

homedepotpro wrote:what size is the barrel?
I think it's 1/2" - btw wannabie, have you tried putting a few slingshot rounds inside the chamber, or don't they fit through the ball valve?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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PneuJose
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Mon Apr 30, 2007 12:11 am

hi wrote:thats a good "im bored, i wanna shoot something" cannon. you know, if you could set it up so that is the ball valve was opened by a spring and held back by a trigger, ill bet you anything it would be more powerful than a sprinkler valve. i did it with a bunch of rubber bands on my first and it could open the 3/8'' ball valve about 3 times faster than i could.

PS reply- i think you should show the cat how to shoot it.
mmm i dont think it can open 3 TIMES more than a sprinkler valve

:roll: or...can it do it? i cant tell the difference(why??...because ive never use spring loaded (or whatever its called) and/or a sprinkler valve.


Anywayzzzz

thats the problem with ballvalves, when u open them u have to ''kick'' the valve so u can open it as fast as u can.
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Insomniac
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Mon Apr 30, 2007 12:58 am

He says it opens the valve 3 times faster than HE could, not 3 times faster than a sprinkler.
I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
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hi
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Mon Apr 30, 2007 2:21 am

Yes, it can open 3 times faster than i can open it.

there is a simple, effective plan.


Image

allow me to explain how it works. the valve it constantly tentioned be the spring. the valve is held closed be a cable/wire. the wire goes through a pully/ fixed loop attached to the barrel. then the cable is released, it opens the valve. You ca make a very simple trigger for this to hold back the cable, does this make sence? soory it its sloppy, it really late and i cant think right now, ill sheck back tomarrow to make sure there arnt any major flaws in the design. I hope this helps, its a great add or.

PS- the spring can be replaced by multiple rubber bands.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
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jackssmirkingrevenge
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Mon Apr 30, 2007 2:28 am

Again, not worth the complication when compared to a modded sprinkler valve.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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wannabie
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Mon Apr 30, 2007 2:51 am

ok the whole thing is made from black polly pipe except the valve and no i haven't tried the big bbs i think it would get jammed but just then i did try a buckshot of around 8 small ballbearings with some wadding the was pretty cool

and homedepotpro if you are talking about the large round plastic ones yes the are alright but unacurite you need some wadding to make them shoot good though ( i just use tissue )
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hi
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Mon Apr 30, 2007 2:54 am

its rally isnt complex. it can be made for free using everyday things. the pully/loop can be made of a coat hanger and the cable from a thin rope. the spring can be a rubber band. its really easy to do.

i know modding a sprinkler valve is easy, but there arent to many spring loaded ball valves out there. i think i have seen three on the forms and countless sprinkler valves. its worth a try and it the worst case you take it off and loose 5 minutes of your time, but i garentee that this works very well and is very effective.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
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skinner
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Mon Apr 30, 2007 3:42 am

If you really want to go the extra distance, and spring load that ball valve.
Ive got a pretty simple one on my gun, thats really easy to make.

Image

The spring is attached to the barrel (i used duct tape, does the job), thento the hole in the lever, then the shoelace is tied to the hole in the lever. the shoelace is then pulled over the bracket, which is attached to the chamber or stock, then once filled, you flick the shoelace off, and then the valve snaps open.

I got the spring from an auto store, its used to do something to carburettors, shoelace of a shoe, and the bracket I made at work.

If you want, you can add a safety device to that setup, all you need to do is drill a hole in the bracket, above where the shoelace is help on it, and then put a pin through it.

Hope that all helps.

good luck.

--Skinner
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