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Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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saefroch
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Fri Aug 12, 2011 12:15 pm

In the future, use teflon tape, not adhesive. Being able to take builds apart is very useful.
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Gun Freak
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Fri Aug 12, 2011 12:57 pm

Noo noo. You use Teflon tape... Not loctite :?
If you used a hose it would be just as secure. Everything is threaded into the aluminum block.

Django, please link to your product page on clippard for the cylinder? I have a theory!!
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jor2daje
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Fri Aug 12, 2011 2:06 pm

are you sure its a spring return single acting cylinder? seems pretty obvious but I built the gun in the thread you mentioned and everything went really easily.

edit: looks like youre pretty sure its spring return.

My only other thought would be that your chamber before the cylinder is to large, so it takes to long for the pressure to drop enough?

Also a larger cylinder may have a stronger spring so pressure can be slightly higher and it will still retract although because the bore is larger the surface area that pressure is working on is also larger so that may not make a difference.

edit2: actually thinking back I had one minor issue to begin with, the hole the cylinders rod fit into wasnt quite aligned with the piston so I would get some binding issues until i adjusted it, this caused similar symptoms to the ones you describe.
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Gun Freak
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Fri Aug 12, 2011 2:22 pm

Clippard makes reverse acting cylinders, that retract when under pressure and extend by spring. At least I think I remember seeing such a cylinder. I'll go look in my catalog.
Edit ok reverse acting cylinders don't fill from the back. This is definitely a single acting cylinder, so I am out of ideas.
Last edited by Gun Freak on Fri Aug 12, 2011 2:30 pm, edited 1 time in total.
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POLAND_SPUD
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Fri Aug 12, 2011 2:29 pm

uhmm

check if the qev is connected properly :D
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Gun Freak
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Fri Aug 12, 2011 2:32 pm

POLAND_SPUD wrote:check if the qev is connected properly :D
Lol :D
He already said the QEV fires though.
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POLAND_SPUD
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Fri Aug 12, 2011 2:33 pm

but it's the other way round.... nahh wait need to find a diagram

though to be honest that's how the gun would operate if it was the other way round


EDIT
Image
That seems to be alright but when you zoom in his QEV it seems the ports are the other way round

EDIT no2
just dissasemble everything and test if the air cylinder extends and retracts when attached directly to the 3 way valve.. if it doesn't - there is something wrong with it or with the 3 way

if it does there is something wrong with your qev
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django
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Fri Aug 12, 2011 6:26 pm

My Qev is a different brand but the diagram and ports are orientated the same as pictured above.

If I have ports hooked up wrong wouldnt the qev not fire!?,though I cant read pnuematic diagrams very well LOL!!.

The Rod is out of alignment by a lot but still clears the bore,i'll take it all apart again :cry:
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LovableAirGuns
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Fri Aug 12, 2011 6:59 pm

Are you sure the 3 way fills the chamber with air when you push the button and then shoots when you realese the trigger becuase that is what mine does.
Sorry for the spelling mistakes because ima using my phone.
django
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Fri Aug 12, 2011 7:20 pm

LovableAirGuns wrote:Are you sure the 3 way fills the chamber with air when you push the button and then shoots when you realese the trigger becuase that is what mine does.
Sorry for the spelling mistakes because ima using my phone.
No,No mine is a Normally Open 3 way= Chamber fills when air is on,push the button then air closes off and fires qev/retracts Cylinder rod at the same time but on mine the rod only retracts when button is released.

I just remembered I put a spring in the QEV because my last gun http://www.spudfiles.com/forums/viewtop ... tml#247309 would fire off when I attatched or removed the airline so I installed a light spring counteracted this. Do I need to remove the spring guys??...
Last edited by django on Fri Aug 12, 2011 7:23 pm, edited 2 times in total.
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MrCrowley
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Fri Aug 12, 2011 7:21 pm

May as well remove it and see what happens.
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LovableAirGuns
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Fri Aug 12, 2011 7:31 pm

You dont really need a spring because your filling from the back not to the chamber.
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POLAND_SPUD
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Fri Aug 12, 2011 7:42 pm

Do I need to remove the spring guys??
yeah and that would explain why it doesn't work
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django
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Fri Aug 12, 2011 8:39 pm

Took the spring out and its still the same!!!??

Just took it all apart and screwed the Air Cylinder directly to the Poppet Valve and it still doesnt operate correctly,it wont retract until I take my finger off the button then it will retract?.

Somehow? the poppet vavle is buggered so Im off to try get a new one today :roll:
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