Full Auto bolt type thing

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Postby An Apple Pie » Tue Nov 07, 2006 11:27 pm

Okay I have been expirementing(sp?) on full auto with my second cannon. Right now I have a safety pop-off valve in place of the blowgun and that seems to work better than the other things I have tried. I also tried attaching a pneumaticly actuated cylinder that actuated the blowgun. It got the pressure directly from the chamber. It worked okay for about 5 shots and then went down hill from there. Anyways I am going to use the safety pop-off valve although the magazine(for paintball barrel) just loads 5 or 6 in one "puff" of air. The last 4 or so simply role out. I need something that will only release one at a time. I know this has been done before but I can not seem to replicate any of them.

Help would obviously help.[:p]
(If you mods think this belongs in the Pneu. Cannon section feel free to move it.)
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Postby markfh11q » Wed Nov 08, 2006 6:24 am

Well, there are a few things you can do, but my favorite is a little complicated.

The paddle system might be a little to violent for paintballs, and it's kind of picky with smaller projectiles.

If you can find a pipe size to sleeve over the 3/4" paintball barrel, you're in business.

On one of GalFisk's guns, he used this system: the barrel was sleeved inside a larger pipe, which was connected to a piston valve. The barrel was cut in half right in front of where the tee loaded in 6mm BB's. I imagine a chamfer would help here as well. Then, he drilled a hole so that when the back section of pipe butted up against the front one, a BB was loaded into the barrel. The back section of pipe was connected to the piston, so when it unsealed and moved back, it uncovered porting on the back section which allowed air through to fire the BB. Since the back section slides back, the loading hole slides back as well, not allowing any other BB's to fire.
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Postby GalFisk » Wed Nov 08, 2006 7:37 am

The mechanism can work, it needs to be carefullt constructed not to break the PBs though. The bolt moves very fast and needs to lift the PBs that are inside the magazine slightly. A good chamfer is required, I had the mechanism splitting plastic BBs in half at first.
I also had problems with double feeding with the original magazine, because air got into the magazine and pushed out another BB when the mechanism reset. I changed it slightly so that it only lets the BB through when the piston face is compressed (it moves about 1 mm when the gun is pressurized to 300 psi). All this may be less of an issue with larger caliber ammo.
More info and pictures here: http://galfisk.kaaven.net/gallery/thumb ... p?album=29
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Postby An Apple Pie » Wed Nov 08, 2006 11:12 am

Thanks Galfisk that helps a lot. Although I do not quite understand how you get that rod, that loads the ammo, to slide back and forth. I saw the animation on it and read the comments but I am not exactly sure what you are saying. Please help.
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Postby GalFisk » Wed Nov 08, 2006 11:37 am

It is connected directly to the main piston of a barrel sealing tee valve, so when the valve is opened, the rod moves backwards. The advantage to this mechanism is that it has only one moving part (except for the trigger valve).
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Postby rdx » Wed Nov 08, 2006 11:41 am

the rod is part of the piston ,when piston moves back the rod moves back .
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Postby An Apple Pie » Wed Nov 08, 2006 12:55 pm

I am using a 3/4" QEV from Mcmaster. Do you think there is a way to do it with this?
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Postby GalFisk » Wed Nov 08, 2006 1:06 pm

Open it up and see if there is a way to attach a threaded rod to the piston, or to replace the piston with a custom built one. If the exhaust port is not straight, you're out of luck.
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