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1/4" magazine Qs

Posted: Mon Jun 23, 2008 3:44 am
by Carlman
Hey guys,

i need to make a magazine (possibly hopper) that will hold bbs and when i fire my gun it needs to fire.

so basically a selector bolt or flapper. :D

now how to make one of bb caliber

Im thinking 1/4" male T, epoxy and some other stuff..

sorry guys, never really took much interest in bolts or semis because never had the urge to make one but now that i have accidently converted the TG6 into semi i need 1 lol

Posted: Mon Jun 23, 2008 8:41 pm
by mark.f
Flappers don't quite cut it with small projectiles, as I found out. They work on larger projectiles like golf-balls because of the increased surface area, but not marbles, and almost certainly not BB's.

Go with the blow-forward breech.

Posted: Tue Jun 24, 2008 2:06 am
by Carlman
thanks mark i will, just gotta get a good design..

using my TG6 i have hooked up a tyre fill handle thing with a trigger a pressure relief button nd gauge directly to the pilot of my QEV. With this i press the trigger to full gun(less than second) and press button to fire and doing this repeditively works a charm.

I have a 30L compressor in which i filled to 110psi and continuinly fired the gun in sucession (no ammo cauz of no mag) and i got 130 shots between 90psi and 110psi!

Posted: Tue Jun 24, 2008 4:40 am
by jackssmirkingrevenge
Making a blow-forward breech like this or this should be a doddle, all you need is some imagination and of course, the stuff that holds dreams together - copious quantities of epoxy ;)

Posted: Tue Jun 24, 2008 7:21 am
by POLAND_SPUD
a tyre fill handle thing with a trigger a pressure relief button nd gauge
that's sounds interesting, care to post a pic of it?

you've got nice results so far... however, making this work well is going to be a PITA..

it seems that it won't work well with blowback bolt but you might consider hooking up a small air cylinder to the chamber of the gun to move the bolt each time you fill/pilot the chamber

Posted: Tue Jun 24, 2008 7:35 am
by jackssmirkingrevenge
POLAND_SPUD wrote:that's sounds interesting, care to post a pic of it?
I think he means something like this:

Image

Essentially it would be like having a pilot chamber with two separate valves, one for filling (the blowgun trigger) and one for firing (the poppet valve to the right of the trigger)

Posted: Tue Jun 24, 2008 7:50 am
by POLAND_SPUD
ohh thx.. I didn't know that these things have a pressure relief button

Posted: Tue Jun 24, 2008 9:02 am
by Carlman
yea its like that, works a treat (but would rather button be to fill and trigger to fire but meh).

When this is done it will either be hooked up to a bbq propane bottle or a 300psi air tank out of an old 20L FE

Posted: Tue Jun 24, 2008 9:05 am
by THUNDERLORD
Looks like you've really come up with something new Carlman!

Other than a blow-forward bolt similar to JSR's design, All I can think of is maybe a two stage trigger.

The trigger could pull the magazine back to drop in a shot, and then press against the pressure relief valve. (accomplishing two functions in one pull)
Since the shot are smaller the trigger pull could still be nice and short. 8)

EDIT: (I type slow sometimes, and didn't know you'd just replied Carlman).

Posted: Tue Jun 24, 2008 9:11 am
by Carlman
i like the idea of pulling trigger back and it also loads a shot that could work

but you couldnt have it in one motion (pilot) as fill valve would be still open.

Posted: Tue Jun 24, 2008 9:20 am
by jackssmirkingrevenge
Consider buying a cheap nailgun off ebay and hacking it apart, they accomplish pilot emptying/refilling functions with a single valve.

Posted: Tue Jun 24, 2008 9:59 am
by Carlman
are they similar to a blowgun or piston valve inside?

i was gong to do that to make a paintball gun

Posted: Tue Jun 24, 2008 10:28 am
by mark.f
You could also make the gun fully automatic by placing a pop-off valve on the pilot. It goes like this: fill, pop-off, fire, fill, pop-off, fire... the rate of fire is adjusted mainly by the flow going into the pilot from your trigger valve (fill valve), choose a pop-off pressure that is convenient.

Posted: Tue Jun 24, 2008 10:35 am
by Carlman
yea i was doing that before with a spare popoff, i am not after full auto rather kind of semi auto

thanks anyway

Posted: Tue Jun 24, 2008 11:05 am
by jackssmirkingrevenge
Carlman wrote:are they similar to a blowgun or piston valve inside?
A pneumatic nailgun is essentially a piston valved launcher piloted and filled by a three-way valve, though instead of firing a projectile, it drives a piston which pushes the nail. Have a look here and scroll down ;)