Page 1 of 2
mini coaxial shells
Posted: Mon May 14, 2007 3:58 pm
by pyromaniac
Mopherman and i were talking again in school. We were talking about the new guns. But deus ex machina and jacks mini coaxial got us thinking.
were wer thinking little shells maybe about 6 inches filled to about fifty psi. they are actuated by puching the hole in the scrader with a little machanism. thus fireing the shot.
pictures will coem soon.
also you could adapt this to make a gatling gun.

Posted: Mon May 14, 2007 5:27 pm
by iPaintball
Thats' a really cool idea, but it seems like it would be very time consuming, and expensive...
Posted: Mon May 14, 2007 5:34 pm
by pyromaniac
Yup but summers the perfect time for that kinda stuff.
Posted: Mon May 14, 2007 6:02 pm
by jackssmirkingrevenge
I've been pondering this idea for ages, mainly taking
this design and chopping off the barrel, making a lot of them and using them as cartridges - it's making them in bulk that put me off.
Also, you're going to need a lot more than 50 psi if you're going to get worthwhile power levels.
Posted: Mon May 14, 2007 6:25 pm
by pyromaniac
i just want to make prototype first shooting around 50 psi.
Posted: Mon May 14, 2007 6:30 pm
by jackssmirkingrevenge
Might as well start at the deep end

higher pressure would give you the opportunity to use the shell's pressure to eject it as well as fire the projectile.
Posted: Mon May 14, 2007 6:33 pm
by pyromaniac
like divert some pressure from the barrel? I am thinking of haveing it be placed up to a longer barrel. like tee off a barrel cap it and stick soem hose going back to the cartridge to shoot it out?
Posted: Mon May 14, 2007 6:35 pm
by jackssmirkingrevenge
no need to divert pressure, it could work like my cartridge combustion:
Posted: Mon May 14, 2007 6:38 pm
by pyromaniac
I dont see how the shoots the cartridge out though. mind explaining?
Posted: Mon May 14, 2007 6:47 pm
by jackssmirkingrevenge
ok.
The pressure is pushing on the projectile, and on the inner base of the cartridge.
the space above is the hole where the air from inside the cart is escaping from. now, 4 arrows pushing to the left, 5 arrows pushing to the right - the cartridge moves back, in the opposite direction to the projectile.
Posted: Mon May 14, 2007 6:54 pm
by pyromaniac
So it basicly shoots the cartridge backwards and out of the gun?
also would just putting a hole in the side of the little coax barrel be enough to let air out and shoot the cartridge out?

Posted: Mon May 14, 2007 6:58 pm
by jackssmirkingrevenge
No need to make an extra holes - it's the barrel hole that allows greater pressure to act on the base on the cartridge than on the front.
see? No extra holes 
Posted: Mon May 14, 2007 7:02 pm
by pyromaniac
Ok cool I'm also thinking of piloting from the scrader. so here my idea. have come copper pipe linded up close to the scrader, with a smaller peice of copper pipe that can slide in it. by pushing a trigger or whatever it pushes the pipeing into the scrader hitting the little button. ill draw a diagram.
kinda like this.

Posted: Mon May 14, 2007 7:55 pm
by Hawkeye
I made a couple of these out of brakeline and copper repair couplings. You need high pressure for such a tiny volume to work well. I pumped to 350 but never assembled a gun to house the "mini coaxials'. You can just hold it in your palm and shoot it by squeezing the valve open. It's like a derringer.
It is more practical to make a larger one way valve to fill it rather than a schrader. It is easier to make a hammer system to tap it open if it is scaled up. Of course this also means making your own pump to screw onto the custom fill valve.
Posted: Tue May 15, 2007 2:56 am
by jackssmirkingrevenge
there is another way of doing things, less efficient but you only need one valve for filling and discharging - it's basically the way the old Saxby & Palmer air cartridges worked, as used in this
homemade m1911 adaptation.
The hammer strikes the body of the cartridge, pushing it forward, while the stem remains locked in the breech allowing the vents to be exposed and the air to flow through the barrel, pushing the projectile along.