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.
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Hubb
- First Sergeant 2

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Fri Dec 19, 2008 3:10 pm
120psi for a 3000cu in chamber is a lot
If you saw the book, you may have noticed I did not include any pressure ratings in there. This is because it is not rated for air and I don't want someone to try and blame me for blowing their right hand off by filling it up to a pressure I quoted.
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john bunsenburner
- Sergeant 5

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Fri Dec 19, 2008 3:47 pm
so air pressure is "stronger" then water pressure?
"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
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MrCrowley
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Fri Dec 19, 2008 3:52 pm
The only thing that matters with water and air pressure is when the pressure chamber fails. If it doesn't fail, there's no difference.
If it does fail, pressurized air will transfer more energy to the shrapnel, meaning the shrapnel travels faster and makes it more dangerous. Because water is heavier, less energy is transferred to the shrapnel so it is a lot safer.
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john bunsenburner
- Sergeant 5

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Fri Dec 19, 2008 3:58 pm
Finally some one managed to explain that in a way i could comprehend, thanks alot Mr.C
"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
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Big Boom
- Private 2

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Fri Dec 19, 2008 4:15 pm
is 1" the biggest sprinkler valve you can get? (I know it is the biggest I have found, I am just curious to find out)
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Hubb
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Fri Dec 19, 2008 4:24 pm
I've seen them up to two inches. They tend to be expensive, though.
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john bunsenburner
- Sergeant 5

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Fri Dec 19, 2008 4:32 pm
what is the common size which you would recomend?
"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
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MrCrowley
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Fri Dec 19, 2008 4:42 pm
1" is the most common among spudders. I'd recommend it over a 3/4" one.
I've seen sprinklers up to 3", though like hubb said they get very expensive.
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Hubb
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Fri Dec 19, 2008 4:43 pm
That depends on what you are trying to do, but, for most applications here, a 1" inline seems to work fine, especially after modding the 'phragm and blowgun.
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john bunsenburner
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Fri Dec 19, 2008 4:44 pm
Ok thank you for your help
"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
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jon_89
- Corporal 2

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Fri Dec 19, 2008 9:13 pm
I have used mine up to 220 psi before with no problems. I tried to mod the diaghram on mine but failed. I am still trying to get it figured it out so I can build a large bore cannon, but I will probably just use two valves.
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Hubb
- First Sergeant 2

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Tue Dec 23, 2008 8:11 am
FYI
I haven't forgotten about this. Just been really busy lately, with Christmas and all.
Anyway, I have added a few things to this:
- I have added more detail on an anti-siphon sprinkler valve
- I've added much more detail to the sections, including photos
- I've been working on another method for advanced modification. When it's successful, I'll add it.
Last edited by
Hubb on Wed Dec 24, 2008 3:07 pm, edited 1 time in total.
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JohnnyBOOM
- Private 3

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Wed Dec 24, 2008 3:24 am
john bunsenburner: "so air pressure is "stronger" then water pressure?"
MrCrowley: "Because water is heavier, less energy is transferred to the shrapnel so it is a lot safer."
Wouldn't it have more to do with the fact that water/liquids are basically incompressible, meaning, when the pressure is released (due to failure) they do not expand further. While with air and other gasses being compressible, when a failure occurs, all that pressure is released in the form of rapid expansion. Kind of like a compressed spring.

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MrCrowley
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