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Posted: Mon Apr 18, 2011 4:25 pm
by JDP12
hmm.. So basically the bolt head slides over the barrel, and when it is pulled back, the barrel is exposed?
Interesting concept, personally I like POLAND_SPUDs, but yours probably works just as well
Posted: Mon Apr 18, 2011 6:04 pm
by POLAND_SPUD
If it has to look like M107 then yours is probably better
Mine would make more sense for a Barrett M95 replica, since it is loaded from the back
Posted: Mon Apr 18, 2011 7:16 pm
by Technician1002
I think the valve design looks more like a toolie valve than a short piston QDV. The operation is similar. The big differences is piston length and diameter. The OD of a QDV is the same as the barrel I'D. The seal is on the piston OD, not piston face like a toolie. In a QDV, the barrel goes through the entire length of the chamber and the spool shaped piston fits inside that.
http://www.spudfiles.com/spud_wiki/inde ... ston_Valve
Posted: Tue Apr 19, 2011 2:53 am
by qwerty
After finishing my 2meters wingspan rc airplane and not being able to fly it because of the goddamn wind
Got picks? I make RC planes too

Posted: Tue Apr 19, 2011 6:48 am
by Demon
Got picks? I make RC planes too
The reason why i want to build this M107 replica is because my RC plane (completly all homemade that waits its maiden flight) is out of access for two weeks
Q.D. fittings can't be disconnected under pressure, can they ?
Posted: Tue Apr 19, 2011 7:44 am
by the unit
Technician1002 wrote:I think the valve design looks more like a toolie valve than a short piston QDV. The operation is similar. The big differences is piston length and diameter. The OD of a QDV is the same as the barrel I'D. The seal is on the piston OD, not piston face like a toolie. In a QDV, the barrel goes through the entire length of the chamber and the spool shaped piston fits inside that.
http://www.spudfiles.com/spud_wiki/inde ... ston_Valve
I also thought from what I could gather this is a toolies valve, with mechanical actuaction as oppose to pneumatic.
Posted: Tue Apr 19, 2011 7:48 am
by Demon
But can a Quick Disconnect be disconnected under pressure ?
Knowing that will modify my plans, so i need to know.
My guess is that i can't, since the two mating parts want to expel each other but are kept together by 4 steel balls. So the friction will make it impossible to take off under pressure.
Amiright ?
Posted: Tue Apr 19, 2011 8:04 am
by Crna Legija
yes they can but at 250+psi its near impossible. and only the female park will hold pressure back.
Posted: Tue Apr 19, 2011 8:13 am
by Demon
So higher the air pressure, the harder it gets ?
At 150 PSI, is it possible to disconnect the two without ripping the gun appart ?
Posted: Tue Apr 19, 2011 6:55 pm
by Gun Freak
Demon wrote:So higher the air pressure, the harder it gets ?
At 150 PSI, is it possible to disconnect the two without ripping the gun appart ?
It will be very difficult...
Posted: Tue Apr 19, 2011 8:03 pm
by warhead052
It may not suit your needs, but add a ball valve inbetween the QD and the air chamber. When you shut the valve, it releases the pressure on the QD and makes it easy to pop off.
Posted: Tue Apr 19, 2011 8:08 pm
by ramses
Not really, depending on your quick connect. I use ball bearing quick connects and they are still almost one handed at 150 PSI.
Posted: Thu Apr 21, 2011 9:53 am
by Demon
It will be fine i will put a ball valve on the pump to depressurize the system.
Here is some progress :
The yellopw thingy is the no-return valve and Q.D.
The CPVC pipe is the air chamber, barrel to the left, trigger to the right (the trigger will be rigged to be installed to the left).
The pump is the only thing left to do. The seal right now is total at lung pressure, so everything is alright !
Posted: Fri Apr 22, 2011 7:50 am
by Demon
Hello again
The pump works perfectly, but I can say as much of the QDV ...
The piston head won't seal, and the o-ring slide lets air slip trough. It should not be hard to repair tough, it will only take time.
Here's Teh pump :
Posted: Fri Apr 22, 2011 9:36 am
by warhead052
Nice job. It looks awesome, does the ball valve help?