Will this semi-auto QEV design work?

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
User avatar
jmez1996
Private 4
Private 4
Posts: 93
Joined: Tue Nov 30, 2010 7:27 am

okayyy so i have recently bought this QEV http://cgi.ebay.com.au/Pneumatic-Quick- ... 1330wt_702

im am planning on implementing it as shown in the diagram below and using a regulator between the tank and the QEV to allow for multiple shots.

my question for the pros is whether or not this would work? or if the valve would not re-pilot because the air is entering the tank side of the valve? in this case would i need to put the tank behind the pilot so that it repilots after each shot?
i only plan on getting 5+ shots. using a barrel of about 6mm inside diameter.

i would also be willing to use a ballvalve inplace of a regulator if it is going to work.
any help would be appreciated as i am new to QEV's.
thanks.
Attachments
design for semi-auto.jpg
design for semi-auto.jpg (28.35 KiB) Viewed 3913 times
lemming124
Private 3
Private 3
Posts: 51
Joined: Sun Oct 18, 2009 6:18 am

should work fine. The QEV will reset itself if it has a spring (I think they all do), ball valve will work in place of a regulator but you'll have to open and close it for every shot.

Alternatively you 3 way mod the blowgun, put the reservoir where the schrader is and reduce the "tank" size.

also, a QEV is works the same way and is similar (in terms of structure) to a homemade piston valve with a spring bumper, it's just more efficient and faster and shouldn't require servicing.
User avatar
AnotherSnappedLine
Private 2
Private 2
Posts: 38
Joined: Tue Feb 08, 2011 10:30 pm

My build is sort of like that- Instead of air pressure behind the piston, Im adding a spring and filling the chamber from behind. I can mod the blowgun actuator by adding a spring-loaded screw to regulate flow.
User avatar
Crna Legija
First Sergeant 2
First Sergeant 2
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia

youd be better of just putting a tiny hole in the piston of the qev and adding a very weak spring behind it, then just filling from chamber.
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
User avatar
jmez1996
Private 4
Private 4
Posts: 93
Joined: Tue Nov 30, 2010 7:27 am

okayy so hopefully it will work but i cant test it till it arrives..
im only worried that that the QEV will pilot on the first shot but then not again as the air is coming from the other side...
User avatar
Crna Legija
First Sergeant 2
First Sergeant 2
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia

if you don't put a spring behind the piston and a small hole in the outer edge of the piston then it will not work, and if you do it then might as chamber fill and reduce you pilot volume
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
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