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Re: Coiled tube - no spring needed

Posted: Mon Nov 12, 2007 12:21 pm
by williamfeldmann
SPG wrote: The problem with a coiled tube magazine is as you've pointed out that any spring would have to be very long. Here's a way round that using air pressure.
Spring doesn't have be very long, only as long as the actual body of the helical, in essence very short for the amount of ammo.
SPG wrote:You use the ballvalve as a filler for your ammo, tip the whole thing vertical and pour your ammo (pink) in, then connect a pump, whatever and pressurise your magazine (yellow). Close the ball valve, and voila, the pressurised air inside the PVC tube forces the ammo forwards into your breach. You could even put this set up inside the guns chamber if you wanted it very clean looking or no doubt attach it with quick connect valves, whatever.
You sure could, of course if you are using paintballs, then you just crushed all of the paintballs with chamber pressure or whatever pressure you are trying to feed with. And you now have a helical tube full of paint and skins to clean out. And if its inside your chamber, reloading and cleaning that would be a real b@tch. There is also the issue of the spherical solid ammo in a nonbinding tube the air will just leak around all the bbs and get you nowhere without a really well designed cup in the end to push the ammo forward. hmmm.... Its a good start to a good idea though, I'll give you that.

Image
(I love this picture :D )

Posted: Mon Nov 12, 2007 12:32 pm
by SPG
I know, and in an ideal world a helical magazine would be fantastic. But there's a trade-off between what would be wonderful and what we can build.

An air-pressure feed system isn't beyond a lot of people's capabilites, machining a helical magazine is.

Posted: Mon Nov 12, 2007 12:42 pm
by williamfeldmann
Quite true, on both accounts. However, air feed systems have limitations that other systems do not, especially when dealing with spherical ammo, which is an excellent choice both aerodynamically and practically. Most notably, it requires precious air, which we also need for our guns.

In truth there would be little machining necessary to build a rough spring driven helical. If you could bend a copper tube or pex without getting kinks you are already 80% done. Making a professional looking helical on the otherhand could require a pretty significant amount of skill, depending on size.

Re: Coiled tube - no spring needed

Posted: Mon Nov 12, 2007 1:58 pm
by ALIHISGREAT
Image
(I love this picture :D )


me too :lol:

Posted: Tue Nov 13, 2007 4:49 am
by Hailfire753
Its a idea with potential spg. Perhaps if there was some kind of piston behind all the ammo it could help keep the air behind it? Paintballs, and many other ammo, are not completely circular, so without it air would escape.

I got it! Perhaps, intead of a ball valve, the helical ube would not exit the canister out of both ends. The helical tube would terminate iside of the PVC canister, with that end semi-blocked by a wire mesh to keep ammo in. PVC containing tube would be pumped to 10-20 psi (or whatever it can w/o crushing ammo) and the ammo would be forced out of the feed tube.

I don't have time for a pic, but the result is a compact, self contained, silent, high-cap mag that only needs to be pumped up once or twice.

Posted: Tue Nov 13, 2007 3:32 pm
by SPG
Err, the ball-valve is only there so you can fill the magazine easily, notice how the helix has vents in it just inside the chamber which let the pressurised air in, and so push your ammo out.

Not saying it'd work well for a HUGE calibres, but for BBs can't see why not.

And yes air is nice for our guns but we're only talking about a very small air consumption. Even smaller if as has been said some kind of piston/magazine follower is used.

Posted: Tue Nov 13, 2007 4:44 pm
by Hailfire753
Ahh, I see. :lol: I basically said the same thing you did, lol. I don't see how bore size affects it though. I am saying that you could just keep the coiled tube inside the pipe, with only a schrader and ammo tube coming out. Looks more like a mag with 1 tube, no?

Ya know, your idea is very do-able. No mechanical springs and stuff. I think I will try this idea first, as it seems the easiest, most reliable, most compact, and most silent design. I can see it now - a group of paintball "infantry" taken out... without knowing who shot them or where they are. The mags would be pre-charged with air, so no clumsy spring-winding. You could keep the ball valve for "hot-swapping" the mags and for reloading a half-empty one.

Posted: Sun Nov 18, 2007 7:42 pm
by iknowmy3tables
good luck on actually sealing that tube

Posted: Mon Nov 19, 2007 6:24 pm
by Hailfire753
What do you mean? If you are refering to the piston behind the ammo, I got it all figured out. I will use JSR's epoxy piston method, and simply fill a 1/2 segment of the greased, curved tube with epoxy. A string will be attatched to this epoxy piston that is just long enough to prevent it from entering the breach, yet still chamber all of the ammo.

If that dosn't seal, I'll simply add an o-ring.

Posted: Wed Nov 21, 2007 6:08 am
by sinper2006
i don't no if anyone has said this but anyway with the ball valve don't just use it for loading also connect a low psi thing up to it like then put Hailfire753 epoxy piston in it then when u reload u unscrew the pipe on ball valve pull out ya piston fill it up replace plug add the pipe on ball valve wow i just made that up as i went along lol