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Posted: Thu Jul 08, 2010 9:31 am
by Gun Freak
jackssmirkingrevenge wrote:ramses wrote:I will fill in for Poland spud and suggest a 3 way valve as the pilot. Or a 4 way, which would allow you to fill from the chamber.
With a 3 way, the air feed is blocked off when the pilot is opened so no need for chamber filling. Hooking up the pilot side to a pop-off should technically allow you to retain the full-auto function.
The three way was what I was thinking about last night for this design, but I never got around to posting it. Oh well...
Anyway, a three way could only be used for semi auto (me likey semi auto) because once it is vented, the air input line is blocked, therefor disabling the gun to fill again. The shooter would have to let go of the button to let it fill again, therefor it can only be semi auto.
Yeah yeah yeah, I build a couple guns a month sometimes but they are usually cheap but this a bigger and harder build so I'll spend a while planning it and I'd use a 3 way but there expensive and I've never really under stood them. Also do they work like piston valves or diaphram valves, and they are triggered electronically arent they.
You can get cheap three ways, or build one for about 5 bucks, or use the Blowgun Three Way, if that doesn't have enough flow then you can hook it up to a cascading piston valve design, three ways are not hard to understand at all. They are not like piston or phragm valves. Here is my design for a homemade one in 1/2" pvc...
Green inlet, blue pilot, red exhaust. Pull back on the bolt to vent the pilot. Three way valves basically control the flow path of the air. They are also called directional control valves.

Posted: Thu Jul 08, 2010 10:23 am
by clemsonguy1125
In your design gun freak wouldn't the pilot be open the whole time?
Posted: Thu Jul 08, 2010 11:56 am
by jackssmirkingrevenge
Gun Freak wrote:Anyway, a three way could only be used for semi auto (me likey semi auto) because once it is vented, the air input line is blocked, therefor disabling the gun to fill again. The shooter would have to let go of the button to let it fill again, therefor it can only be semi auto.
Fair point, that'll teach me to articulate pneumatic pathway assertions while I'm supposed to be working

Posted: Thu Jul 08, 2010 12:04 pm
by POLAND_SPUD
@JSR
well... you
can achieve full auto with the use of DCV valves

Posted: Thu Jul 08, 2010 12:28 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:well... you
can achieve full auto with the use of DCV valves

So much for there being sophistication in simplicity

Posted: Thu Jul 08, 2010 4:32 pm
by Gun Freak
clemsonguy1125 wrote:In your design gun freak wouldn't the pilot be open the whole time?
No, the pilot is open to the inlet the whole time but only open to exhaust once you push the button, and once you push it the inlet is also blocked off so it can pilot faster.
Posted: Thu Jul 08, 2010 4:45 pm
by clemsonguy1125
Oh ok, this gun is getting more aand more confusing, if i build it, im building JSRs sketch, and is there a seperate pilot valve, such as a blowgun
Posted: Thu Jul 08, 2010 4:54 pm
by POLAND_SPUD
naah it isn't confusing... what I posted above is just a self switching version of a typical 3 way + QEV combo
the 3 way + QEV + air cylinder is probably the simplest way to build a working semi...
well I don't think I even recall anyone who tried to build a gun using that design and he failed but there have been quite a few failed BFB
@jsr
So much for there being sophistication in simplicity
now I get it...
let me quote Antoine de Saint-Exupery
In anything at all, perfection is finally attained not when there is no longer anything to add, but when there is no longer anything to take away.
sure there are some things you can take away from the QEV + 3 way + air cylinder combo...
the air cylinder is not 100% required and you can just use a simple T
instead
you can get rid of the QEV (but it is convenient because DCVs with large porting are relatively expensive)
but you can't take away the 3 way
you might think that the hammer valve or piston valve filled through chamebr side is simpler but that's delusive...
The design I posted above (fullauto circuit) is just a 3 way combo that switches itself as soon as pressure is present at port P... I'd say it is as simple as it gets...
sure the valveless design does seem a bit simpler but it is something completely different from this
Ahhh why did you mention 3 way valves !! I almost forgot about them...
now the voices in my head are saying 'valves.... valves....... valvessssss!!

'
Posted: Thu Jul 08, 2010 4:59 pm
by clemsonguy1125
But what I dont get is why is a three way nessacery, why not just use a blowgun
Edit-Mines still gonna be a full auto, I could use a QEV Pop-off combo, but it would still have a BFB
Posted: Thu Jul 08, 2010 5:43 pm
by Gun Freak
The three way would only be necessary if you were to fill from the pilot side to prevent honking.
Posted: Thu Jul 08, 2010 5:53 pm
by clemsonguy1125
It wont honk if i fill it quickly, and also, does honking just annoy you or does it reduce performance
Posted: Thu Jul 08, 2010 7:16 pm
by Gun Freak
Just annoys me I don't think it makes the gun perform any different, I find it kind of funny actually so I don't care about the honking. On my first piston gun, also my first gun that used a sprinkler valve, it honked on the first fill and I was like "what the hell?" lol I have a video of my first shot. It sucked, put a AA about 50 fps lmao
Posted: Thu Jul 08, 2010 7:19 pm
by clemsonguy1125
wow i didnt take videos till my machine guns and piston valves, this guns defianatly going full auto
Posted: Thu Jul 08, 2010 7:31 pm
by Gun Freak
Its uploading, hang on a minute, I'll post it here.

Posted: Thu Jul 08, 2010 7:35 pm
by clemsonguy1125
Was that your first attempt at a Piston Valve, and that airsoft handle keeps popping in all your guns