'Onslaught' Another 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.
Gsu
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Tue Apr 17, 2007 5:51 pm

Well, here's my very fist pneumatic :P

1.5L aluminum chamber.
QEV slightly modified.
6feet 3/4" as main barrel, definitely packs the biggest punch energy wise. I also have 3.5feet and 8feet 1/2" barrels, I only shot the 8feet barrel twice since I haven't got a breech loading system yet nor an 8feet ramrod.
The small ball valve is to minimize the pilot volume before firing and makes it possible to disconnect the pump without triggering the gun.

At the moment I mainly fire spuds. Batteries or cylindrical bearings at close range if I want damage. And my own home made projectiles made by making an arrow out of soda bottle labels with a screw in the tip :)
I'm going to shoot some marbles soon.

I still have a huuuuuge To-Do list tho, I'll update when I get the following done:
-Measure projectile velocities using laser gates from college
-Damage pics
-Mount green laser pen onto it (10mW green, so the laser 'll draw a clearly visible line through the air at night ;) )
Next up would be creating my own piston valve, use the oxygen bottle, 10feet+ barrel, over 1000psi and a mounting for the whole thing (hehe ambitious :P )
Attachments
Onslaught with small barrel
Onslaught with small barrel
closeup (lots of nipples, I have to deal with metric <> bsp)
closeup (lots of nipples, I have to deal with metric <> bsp)
down the barrel
down the barrel
1/2" barrel and oxygen tank mounted
1/2" barrel and oxygen tank mounted
some dmg from batteries, its sheet metal with some plastic cover
some dmg from batteries, its sheet metal with some plastic cover
barrels, I leave the sleeves on for strength and cus the copper remains nice n shiny that way
barrels, I leave the sleeves on for strength and cus the copper remains nice n shiny that way
pressure vessels waiting to get threaded (the oxygen bottle is iron/steel, better weld something to it than thread it if I want to take things over 1000psi?)
pressure vessels waiting to get threaded (the oxygen bottle is iron/steel, better weld something to it than thread it if I want to take things over 1000psi?)
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Velocity
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Tue Apr 17, 2007 5:54 pm

Looks AMAZING. Very clean, and I am glad someone else understands the importance of long barrels (even though I do not have too many because of where I live :x )

One question though: what is the point of that copper pipe behind the pressure gauge and fill valve assembly?
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Pete Zaria
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Tue Apr 17, 2007 5:58 pm

rmich732 wrote:One question though: what is the point of that copper pipe behind the pressure gauge and fill valve assembly?
That's what I was wondering, too.

AMAZINGLY clean job for your first pneumatic. Way better than my first. Keep it up and stick around!

Peace,
Pete Zaria.
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spudthug
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Tue Apr 17, 2007 6:00 pm

lol rmich took my question..what the hell is the copper for behind the fill assembly and psi guage??

btw GREAT cannon especially for a first!!

pete beat me to second psot..we must ahve been typing at same times hehe
Last edited by spudthug on Tue Apr 17, 2007 6:00 pm, edited 1 time in total.
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
Gsu
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Tue Apr 17, 2007 6:00 pm

functioning as a gunstock so you can hold it like a rifle, have it rest on your shoulder :) and a nice addition is that when you open the ball valve after firing it doesnt stress the gauge by subjecting it to rapid pressure drops because the air from the piece of pipe also needs to flow thru the valve, or would you say the gauge has absolutely no problem with rapid pressure drops like when firing?
A question just popped to my mind: why don't I see ppl using aluminum parts ?
I actually was gonna buy a 10feet one but I got these (hard)copper ones for free EDIT: barrels
Last edited by Gsu on Tue Apr 17, 2007 6:38 pm, edited 3 times in total.
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spudthug
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Tue Apr 17, 2007 6:03 pm

10 feet of what? aluminum pipe? for a barrel? i have big asss aluminum barrel that is like 12ft long and schmanman has one for the swat that is like (27 feet long?) big...for chamber and stuff idk i havent ever seen anyone use it...i know most of it is pressure rated but u would ahve to check before u use it...ok im going to watch tv be back in an hour
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
locksmith
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Tue Apr 17, 2007 7:45 pm

I made my own aluminum tank out of 2"schedual 80 but you will have to wait till competition time to see it.nice weapon you built.keep up the good work
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frankrede
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Tue Apr 17, 2007 9:03 pm

Its beautiful.
I love cannons made of metal.
1000psi?
Thats scary!
Are you sure your valve can take it?
Current project: Afghanistan deployment
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pyromaniac
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Tue Apr 17, 2007 9:09 pm

All i have to say is holy crap.

that things flippin awesome!

i'm kind wandering about the long pipe after the exaust.
:pottytrain3:
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VH_man
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Tue Apr 17, 2007 9:13 pm

Is that QEV rated for that kind of pressure? otherwise thats a SWEET cannon. how accurate is it? you should make a Bipod so you can actually hold it and shoot marbles..... i have a feeling this would work REALLY well with this. either that or order steel balls from mcmaster that match the right diameter to fit in your barrel.......... im doing that for my "sniper" cannon.
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homedepotpro
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Tue Apr 17, 2007 9:13 pm

i think that blow gun isn't rated to 1000psi, i think i have the same one and it says its rate for 90psi

anyways what would you use to pressurize it that high, just wondering
Gsu
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Wed Apr 18, 2007 1:44 am

Both the valve and blowgun are rated 150psi, I'll be making my own piston valve for higher pressures. I didnt think about the blowgun yet tho.. ball actuate the piston?
So far I'v only shot with very inaccurate ammo so cant tell you much about its accuracy tho I'd say its very high since I have a long barrel and it's hard copper so there is no dents or bents in it.
I was thinking of a shock-pump to pressurise that high :)
pyromaniac wrote:i'm kind wandering about the long pipe after the exaust.
haha guess you'r referring to the small piece of pipe that most were wondering about :p
It makes you able to have the gun rest on your shoulder, and it is disconnected from the system by closing the tiny ball valve prior to firing to minimize the pilot volume :)
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iPaintball
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Mon Apr 23, 2007 9:16 pm

Most metal ball valves have a max pressure of 600 psi.
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jackssmirkingrevenge
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Mon Apr 23, 2007 11:06 pm

Very nice, definitely get a shock pump, you'll be amazed at what a difference upping the psi will do :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
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spudthug
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Tue Apr 24, 2007 6:04 am

actually most ball valves are rated alot higher....like ones for paintball nad stuff...he could take a ball valve to 1000 psi...mmm i wouldnt take copper to 1000 psi....or that psi guage, or the shrader...
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
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