Travel of energy through gun

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
alkapwn1
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Sun Oct 05, 2008 10:43 pm

I was wondering if, for asthetic reasons, instead of doing a simple 2 90 degree coupler over under, I routed the expanding gasses through a longer route. It would take the energy from the combustion longer to get to the barrel and projectile but not by much.

Typical over under:
___ ___________________
l _ l___________________l
l__l
l l_ _____________
l____l_____________l

Longer route:
___ ___ __________________________
l _l___ l__________________________l
l__l __ _____________________
l l_ ___ __/ __l_____________________l
l____l___l __ /

The bottom long sections would be the combustion chambers
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Lentamentalisk
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Sun Oct 05, 2008 11:02 pm

Assuming you are not using a burst disk, then the entire portion of the cannon that is not farther down the barrel than your ammo is part of the combustion chamber. Check your post, too many spaces get deleted, use periods instead.
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alkapwn1
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Sun Oct 05, 2008 11:06 pm

sry, now I see how the image got messed up. umm, whats a burst disk?
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CasinoVanart
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Sun Oct 05, 2008 11:09 pm

alkapwn1 wrote:sry, now I see how the image got messed up. umm, whats a burst disk?
A burst disc is a device used to hold back pressure, then burst. More power can be achieved in most spudgund through the use of a burst disc.
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starman
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Sun Oct 05, 2008 11:21 pm

Actually the same amount of power just applied to the barrel faster. The burst disk just acts like a very fast valve and therefore the projectile is subject to more pressure before it leaves the barrel.
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psycix
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Mon Oct 06, 2008 10:46 am

The flamefront will have to travel through the turns before all fuel is burned (and you want that to happen ASAP)
Therefore, you should place an extra spark gap in the turns to compensate for that.
As long as the elbows and turns are the same or larger diameter then your barrel, you will be OK.
Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

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alkapwn1
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Mon Oct 06, 2008 6:45 pm

Thanks, and I'm just going to go with the simple 2 90 degree turns. I have an idea for my breech loading mechanism. I'll make a pic of it and post it. Its a prettier version of the unscrewing barrel type breech. Im making this gun with asthetics in mind greatly, It won't be as unsightly (no offense) as just a standard spud gun.

Here is the pic

Image

The real one will be posted when it is built
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