QEV, 3 way valve, slide valve help

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
1nxtmonster
Private 4
Private 4
Posts: 91
Joined: Wed Oct 02, 2013 3:36 pm

But shouldn't a slide valve be balanced? or is it balanced, but just more friction?
User avatar
bladeul2006
Private 3
Private 3
Posts: 56
Joined: Wed Feb 13, 2013 12:08 pm

it is balanced, just more pressure on the o-ring seals, so more friction
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 582 times
Been thanked: 347 times

pressure increases compression on the slide valve o-rings, which increases friction.
hectmarr wrote:You have to make many weapons, because this field is long and short life
1nxtmonster
Private 4
Private 4
Posts: 91
Joined: Wed Oct 02, 2013 3:36 pm

Ah. Due to how my trigger is attached to the slide valve, the friction is increased by a leverage force to the point that the return spring won't return the trigger. I then did some experimenting with a flow regulator/restrictor and blowgun valve, the results were way better. At 90 psi I was getting results equal to about 120 psi with slide valve. Plus, the trigger pull is a lot smoother. I'm thinking that I wasn't pulling the slide valve fast enough to get full pilot flow before the qev actuated.

Size is a major issue with a blowgun and tee, so I purchased an inline blowgun that is a lot more compact and doesn't need a tee:
106346s.jpg
106346s.jpg (15.61 KiB) Viewed 3674 times
User avatar
bravootome
Specialist 3
Specialist 3
Romania
Posts: 334
Joined: Mon Oct 14, 2013 11:11 am
Has thanked: 1 time
Been thanked: 2 times

. Plus, the trigger pull is a lot smoother. I'm thinking that I wasn't pulling the slide valve fast enough to get full pilot flow before the qev actuated.




it means something is wrong with the piston, it doesnt matter how fast you push the pilot. the QEv must respond the same, if it is well done..................
come undone
1nxtmonster
Private 4
Private 4
Posts: 91
Joined: Wed Oct 02, 2013 3:36 pm

It's a store-bought qev valve.
User avatar
Major Collins
Specialist 2
Specialist 2
Posts: 264
Joined: Wed Nov 18, 2009 6:18 am
Location: Western Australia

1nxtmonster wrote:Ahhh...how bout this: http://www.ebay.com/itm/MEAD-MV-50-NEW- ... 35c017e55b

Due to size constraints, i'm not sure if it can fit in the gunstock. So I was doing some thinking, and came up with a shut-off valve:
Screen Shot 2014-02-08 at 11.58.18 AM.png
wouldn't this be a better, having a piston with a one way valve?
Image
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

  • Similar Topics
    Replies
    Views
    Last post