Double Barreled Pneumatic Spud Gun

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.
ALPHA[GWP]
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Sun Apr 11, 2010 1:13 pm

Here's a prototype i might build , this is my first post here soooooo , any ideas would be great for this

Ps i can turn a normal valve pretty fast!

Anyone know if this will work , or end in an epic failure?[/img]
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clemsonguy1125
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Sun Apr 11, 2010 1:19 pm

It will work but performance will be bad. By turn i assume you plan to use a ball valve. Id upgrade to a sprinkler valve at least. If you want power then use a single barrel. Also your c:b is bad. You need a much longer barrel. And this should be in the pneumatic disscusion not showcase. Please do some research before posting. Heres a similair cannon but it has one chamber not two.
http://www.instructables.com/id/How-To- ... asy-Steps/
Last edited by clemsonguy1125 on Sun Apr 11, 2010 1:31 pm, edited 1 time in total.
That is all.
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jackssmirkingrevenge
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Sun Apr 11, 2010 1:25 pm

As pointed out above, a ball valve is not the most ideal, especially for two barrels. As an alternative to a sprinkler valve, you could also have the ball valve spring loaded for faster and more consistent opening.

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The volume of your air chamber should ideally be around equivalent of your two barrels, especially if you're pumping by hand.
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iknowmy3tables
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Sun Apr 11, 2010 3:25 pm

I would recommend that you just make you pneumatic gun and have a removable threaded connection at the valve so you can switch barrels then you can build a variety of barrel sets to use including this double barrel you have in mind
ALPHA[GWP]
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Sun Apr 11, 2010 3:37 pm

I was thinking about that , but if i jammed something really tight in the barrel , the whole thing would fly off , So im going to glue the base of the barrel on , which would be around 4 or 5 inches , than add an extension
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c11man
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Sun Apr 11, 2010 4:01 pm

if the barrel had a threaded adaptor properly attached to the end it will not fly off if the ammo became jammed
iknowmy3tables
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Sun Apr 11, 2010 6:09 pm

yeah that should never happen, and I've never heard of such a case, what your suggesting just creates dead space and ruins preformance you know you can buy valves with threads on them, buy one, unless you can't find proper non-dwv threads for the chamber side
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Technician1002
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Sun Apr 11, 2010 11:14 pm

The shorter the path between the chamber and the barrel the better.

The fewer bends in the path the better.

The larger the path the better.

The shorter the path the better.

For a high performance double barrel where it is desired for both barrels to fire together would be a dual cannon arrangement with 2 chambers, 2 sprinkler valves, A pressure bridge between barrels and the trigger, and a pressure bridge between chambers.

Two chambers made into a U shape with two elbows at the breech end feeding 2 sprinkler valves, feeding two barrels joined by twin T's in a cross feed would do the job.

The trigger would trigger both sprinkler valves. One will open first. The barrel cross feed (also a support to keep the barrels in align) would provide rising pressure on the outlet of both sprinkler valves, triggering the second one so both dischage together.

Your drawing already has twin chambers. Put twin valves on it with another cross brace between the barrels at the outlet of the twin valves.

I don't have a way to sketch it at work.
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grock
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Sun Apr 11, 2010 11:20 pm

i seem to remember someone building a double barrel before, and saying that unless they used really consistent ammo, the consistency of the shots was not real great, caused by more power going to one barrel and not the other. also, IIRC, it was fixed by having a 3 way ball valve to fire the barrels induvidually
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Mon Apr 12, 2010 2:26 pm

yeah multi barrel setups tead to have this problem, you' might see some people make a volley barrels for bbs, but it's kinda pointless, if you want to fire more projectiles just put them in the same barrel with some wading
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