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Posted: Sun Jun 27, 2010 9:13 am
by lozz08
In order to do this you are going to need an air cylinder and a piston for your blow back or blow forward mechanism. Make that first and then build the gun around that.

Posted: Tue Jul 13, 2010 9:11 am
by django
Mr Dino= any progress on making this Pistol??,I personally have had no time lately to even get started on one!,the joys of family life :P

Posted: Mon Sep 27, 2010 1:58 am
by MrDinoRAWR
Hey,

Iv been working on it. Were could i find a pin valve thats in a t-shape? It will be for the trigger to operate the air flow. I'v seen them somewhere before. Similar to the picture.

Thanks

[/img]

Posted: Mon Sep 27, 2010 3:39 am
by POLAND_SPUD
Were could I find a pin valve that's in a t-shape?
Almost all places selling pneumatic and/or hydraulic stuff have them.
They are called throttle valves or flow control valves.
pics

EDIT
Oh BTW... 'places selling pneumatic stuff' does not mean hardware shops that have air tools. I meant shops selling real pneumatic stuff - valves, fittings, regulators, air cylinders etc.

Posted: Mon Sep 27, 2010 5:04 am
by MrDinoRAWR
Okay, thanks for the name of them. Helped alot =)

Posted: Tue Sep 28, 2010 2:26 am
by lozz08
Are you thinking of having a hammer strike the valve to fire? If the co2 is going to be stored behund that valve then you might find it will fail.

Posted: Tue Sep 28, 2010 4:20 am
by Crna Legija
i think its a needle valve for flow control not a hammer valve

Posted: Tue Sep 28, 2010 7:35 am
by lemming124
cheaper co2 cartridges can be had at cycling stores! they use them in bike pumps :D

Posted: Tue Sep 28, 2010 10:26 am
by lozz08
I personally gave up on co2 a while ago. It really is just a PITA. Expensive, and freezes the feck out of many a valve. Mr dino, use liquid propane instead. You can make yourself refillable mags and fill them from a large propane tank.

Liquid propane will still vaporize at a constant 300 psi. Co2 vaporises at around 850. With higher flow, the propane setup will give you the same power as a co2 setup, unless you are planning on making the gun fully metal internals with soldered or welded joints, because using standard homemade materials and construction, you won't be able to take advantage of the higher pressure anyway; the build will not handle it.

Oh and, lemming, what bike stores are you looking in? Because last time i looked tyre refill cylinders from bike shops were about minus 10 on the good value scale.

Posted: Thu Sep 30, 2010 1:51 am
by MrDinoRAWR
Hi,

The whole needle valve idea was when i was thinking of making the pistol full auto and using a vortex block. I'v started thinking more that i want it semi now. Unless it has a huge ass long clip, a little pull of the trigger and that will be a clip empty. I don't think my bb's that i'v bought off ebay have made it through customs, im most likley changing my design to propel air rifle pellets or metal bearings.

The auto idea would more suit maybe a machine gun or something, maybe not a pistol as much. Lozz08, what are you talking about with making refillable mags? If you have good idea's on the construction of them could you lend me the thought, please.

Posted: Thu Sep 30, 2010 2:18 am
by jackssmirkingrevenge
MrDinoRAWR wrote:The auto idea would more suit maybe a machine gun or something, maybe not a pistol as much. Lozz08, what are you talking about with making refillable mags? If you have good idea's on the construction of them could you lend me the thought, please.
Look at lozz08's earlier project, made with some custom parts it could be made to fit in a compact pistol sized package.

Posted: Thu Sep 30, 2010 9:49 am
by lozz08
An airsoft mag usually looks like this.

Image

The green is liquid propane. A hammer hits the purple button, which opens the valve (yellow) for a shot. You could use a schrader where the yellow is. You could fill the chamber to say 400 psi with a shock pump.

When you insert the mag, the schrader goes into an o ring. The chamber can now be vented by a blow gun.

Or you could just have an onboard chamber like i did.

Posted: Thu Sep 30, 2010 9:57 am
by jackssmirkingrevenge
jackson pollock wrote:An airsoft mag usually looks like this
Have a slightly less modern art version :)

Posted: Thu Sep 30, 2010 10:11 am
by Technician1002
lozz08 wrote: Liquid propane will still vaporize at a constant 300 psi.
Might want to recheck the vapor pressure graph for propane.
The 300 PSI pressure is only on good hot days.
Image

Posted: Thu Sep 30, 2010 10:32 am
by lozz08
Ah, I see. Thank you, i have heard about differences in pressure on cold dats, but that's large.

@jsr laugh at me all you want, you're just showing my talent is over your head.
:withstupid: