combustion bbmg

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lukemc
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Thu Mar 22, 2007 4:16 pm

i was trying to come up with a practicly way to shoot my bbmg without carrying around a giant air compresser. if this idea is stupid please let me know i was thinking of making a small pvc air tank with a ball valve and some kind of detatchable end i would close the ball valve and spray in some propane then clase the chamber and ignite it the idea is the pressure will be traped inside the tank and then open the ball valve (witch is connected to the bbmgs blowgun) and release the pressue via blow gun. from what i understand the max pressure a combustion cannon gets up to is 80 psi and that would be perfect for my bbmg. it seems like it would only take a few seconds to repressurize there for makeing it some what practicle. so my question is: is it posible to containg an explotion inside 3" SCH80 pvc?
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imablackskater
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Thu Mar 22, 2007 4:21 pm

it might be posible but you will not always reach 80 psi yes the combustion pressure system would create this pressure rapidly but also may leek you will need to seal up all places where you have things such as ignitors and electrodes going in.
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jackssmirkingrevenge
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Thu Mar 22, 2007 4:26 pm

In a word, no.

The gasses resulting from combustion will cool down and the pressure will be lost.

edit: there is a way you could use a combustion reaction to compress air, in the manner of the sims-dudley dynamite gun which used a black powder charge to drive a piston down a tube to drive air past a one-way valve and store it in a chamber - effectively a single-stroke compressor.
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Punstype
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Thu Mar 22, 2007 10:00 pm

hey lukemc i was just at lowes and found this it costs about $100

you could hook this up and take your bbmg anywhere you go,and this

thing is refillable. its a co2 tank.i think it would be better to

use this to power your bbmg
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boilingleadbath
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Fri Mar 23, 2007 6:21 am

I would expect the gasses to cool down fairly quickly... so it'd probably be best to forgo the stopcock, and just route the plasma conduit to the randomized pellet selector.

If we're lucky, we'll get a fair amount of mass throughput.

(translation: Just connect the chamber directly to the BBMG... with any luck, that'll give us enough time to to shoot a hundred or so BBs)

...and, yes, 3" sch 80 PVC will have no trouble containing the pressure... but so will cheaper stuff, like sch 40.
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CpTn_lAw
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Fri Mar 23, 2007 7:54 am

do not use this kinda CO2 setup. I've used it once until the pressure gauge popped off in my stomach. 800psi of CO2 pushing it. I had a bad bruise for 2 weeks.
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Redcoat
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Thu Jun 07, 2007 3:18 am

It's a good idea and ive ponderd it. Would be awesome if you made it.
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jimmy101
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Thu Jun 07, 2007 4:17 pm

Nope won't work.

Like jacksmirk said, the gases will cool too quickly and the pressure will drop (combustion guns are heat engines, lose the heat and you loose the energy). The flame temperature of propane is something like 4300°F. The heat capacity of air is tiny. The combustion gases will loose heat so fast I doubt you would even have time to open a ball valve.

Unless you are talking about an insanely long piece of pipe you won't have enough volume in the chamber to keep the gun running for even 1 second.
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singularity
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Thu Jun 07, 2007 6:58 pm

hey lukemc i was just at lowes and found this it costs about $100

you could hook this up and take your bbmg anywhere you go,and this

thing is refillable. its a co2 tank.i think it would be better to

use this to power your bbmg
don't buy it, its only got like a 9oz tank, for that same $100 you can have yourself a 5lb regulated co2 system. it will last a hundred times longer, for a new aluminum 5lb co2 tank its $60 and a regulator is $40

<a href="http://www.beveragefactory.com/index.shtml">this</a> is the place i bought mine from and i couldn't be happier with it. it lets you dominate the kids who have the $300 aegs
be sure to check out my <a href="http://www.spudfiles.com/forums/ak-styl ... 9.html">AK Styled Vortex Gun</a> and my <a href="http://www.spudfiles.com/forums/at-4-t9627.html">AT-4 Rocket</a>

upcoming projects... finalized clip fed BBMG and ball point pen sniper
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