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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.
paddo
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Mon Apr 30, 2007 4:20 am

iv just got myself a 25mm (inch) sprinkler valve off ebay. i want to make a 'sniper' type of cannon. im thinking about rifling it but 'sniper' is the easiest way to describe wat id like to make. it will be a modded sprinkler valve. id mostly like to shoot marbles and ball bearings but i want to have interchangeable barrels which is easy enough to do.

im not sure which type would have the best performance. either a under and over.

or an inline like this : (thanks to the maker of this nice gun)

http://www.spudfiles.com/forums/melkors ... -t150.html

im leaning toward an inline gun because its simple and not as many joins.

the question is can i get as much power/accuracy out of an inline which would obviously have a smaller chamber than an under and over ? the biggest barrel i will have on it will be about 30mm (just over an inch)

by power i mean that i want it to be accurate over an average distance but also want things to go a fair way aswell.
and i was also thinking about an inline but having it something like this :


thanks
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jackssmirkingrevenge
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Mon Apr 30, 2007 4:26 am

An inline configuration should technically yield more power than an over-under (with everything else being equal) because the air can travel straight through without losing energy going round bends.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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mega_swordman
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Mon Apr 30, 2007 5:23 am

Because it is an inline valve, the inline gun would be more functional since it won't have any dead space for the air to travel through. Also, I personally think it would be easier to make an in-line look more like a rifle.
"Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity." George S. Patton
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jackssmirkingrevenge
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Mon Apr 30, 2007 5:33 am

mega_swordman wrote:Also, I personally think it would be easier to make an in-line look more like a rifle.
Certainly, at least the blowgun trigger would be in the right place, like on Melkor's gun.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Hotwired
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Mon Apr 30, 2007 12:07 pm

I disagree on the dead space, power and functionality. They are only an issue if you don't design it very well.

But since you only want a 30cm barrel you'd have something too small for a 'sniper' design if you went for an over-under layout and it would be cheaper and easier to make a chamber-sprinkler-barrel inline.
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meatballs
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Mon Apr 30, 2007 2:54 pm

i made something like what you're doing, i used an inline configuration and it looks great, if your going for looks i agree with mega_swordman inline is better. other than that i dont see an under-over design cutting performance since although the air has to turn, it does so around rounded corners through smooth pipe, and it'll have to completely reverse direction inside the sprinkler valve so it shouldn't affect things much. i would go for the inline if i were you.
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super spuder
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Mon Apr 30, 2007 3:05 pm

if you want to make a sniper, inline is the way to go. in my opinion. so get off the computer and go and build it :D
paddo
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Tue May 01, 2007 1:15 am

super spuder wrote: so get off the computer and go and build it :D
thanks for the fast replys guys. i have decided to go inline. and yeh id like to be able to go out rite now to my shed and make it but i have to get some more parts first. and wait for the sprinkler valve to arrive which was shipped yesterday.

thanks for the replys and ill get sum photos asap. :D
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meatballs
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Tue May 01, 2007 2:30 pm

make sure you post pics when you're done, cant wait to see it.
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lukemc
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Tue May 01, 2007 4:04 pm

i would imagine that inline would be better from a looks stand point. it is very hard to build a stock for an over under without it being too strange looking
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paddo
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Sat May 05, 2007 3:23 am

the valve arrived today. i modified it fully and it took tops of half an hour to do. it seals completely no leaks at all. as soon as i can get some new pipe for the rest ill get working and put some pics up. i tested the valve on my over and under which normally i just have a ball valve on and the sprinkler valve works very well.
thanks for the replys and ill get to work asap. :D
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