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Posted: Thu Aug 01, 2013 4:35 pm
by Gun Freak
The head of the fire extinguisher is basically useless. You may be able to use just the threaded part as a bushing (tap be threads in the hole), but the rest probably won't do you much good.

Once you get it taken apart we'll see if you can modify the plastic threads so that you could at least use the extinguisher as an air tank. I believe that type is tested to 300 psi, so you should be good.

Posted: Fri Aug 02, 2013 3:09 am
by eliechahine
Are you sure it's useless?

The daystate any many other commercial airguns use similar valves , i took it apart for a better view..

and my god the spring is huge

Image
Image

The blue tube would screw in the valve and the entire thing inside the fire extinguisher..not sure if the blue plastic tube is going to be usefull in my 150 bar tank

Posted: Fri Aug 02, 2013 5:23 am
by jackssmirkingrevenge
With a weaker spring it might do. Try pressurising it and using an actual hammer to tap it open, see how that goes :)

Posted: Fri Aug 02, 2013 5:33 am
by eliechahine
Will do as soon as i get my air tank which should be sometime tomorrow.

Anyways i have been reading about some posts and found this gun..it really amazed me and wanted to check about something.

http://www.spudfiles.com/forums/psg-1-s ... 21786.html

pic of the gun http://www.hostingpics.net/viewer.php?i ... G_3190.jpg

I was wondering if the blowgun in the second pic is attached to anything to pilot the qev, and if i keep squeezing the blowgun will that give me full auto?

Posted: Fri Aug 02, 2013 6:04 am
by jackssmirkingrevenge
eliechahine wrote:I was wondering if the blowgun in the second pic is attached to anything to pilot the qev, and if i keep squeezing the blowgun will that give me full auto?
Not quite. He uses a ball valve to cut off flow from the main chamber and fill the firing chamber every time. Every time squeezes the blowgun, you only get one shot.

If you want full auto, you will need a pop-off pilot.

[youtube][/youtube]

If you want semi auto, it's best to pilot with a three-way valve.

[youtube][/youtube]

Posted: Fri Aug 02, 2013 6:41 am
by eliechahine
Not quite. He uses a ball valve to cut off flow from the main chamber and fill the firing chamber every time. Every time squeezes the blowgun, you only get one shot
I was thinking the same as you, until i rechecked his video and noticed he doesn't open and close the ball valve every time he wanted to take a shot, he just opens it and he get the semi auto.

Posted: Fri Aug 02, 2013 8:25 am
by eliechahine
So what do you think .. open the valve once and the chamber will pressurize by itself or should i keep opening and closing the valve before every shot?

It's not what he did in the video though

Posted: Sat Aug 03, 2013 12:31 am
by jackssmirkingrevenge
eliechahine wrote:So what do you think .. open the valve once and the chamber will pressurize by itself or should i keep opening and closing the valve before every shot?

It's not what he did in the video though
Note that he leaves the ball valve cracked open. This means that when he pulls the trigger to empty the QEV pilot, gas is coming out of the blowgun but at the same time entering from the main chamber. This not only inefficient in terms of gas wastage, but for a given pilot valve, you will also have reduced performance.

This is why 3 way valves are a better idea, because actuating them simultaneously empties the pilot and cuts off the gas from the main chamber.

Posted: Sat Aug 03, 2013 1:49 am
by eliechahine
By 3 way valve you mean like the blue slide valve in the video you shared with me in an earlier post?

or one of these:

http://www.stcsupply.com/Fitting/3%20WA ... 20PIPE.jpg

Posted: Sat Aug 03, 2013 1:57 am
by jackssmirkingrevenge
Yep. Some info on them here: http://www.spudfiles.com/forums/directi ... 20438.html

They also come as "trigger" style valves: http://www.ebay.com/itm/JM-07-1-4-PT-Th ... 2c6a85a32c

Posted: Sat Aug 03, 2013 2:15 am
by eliechahine
Alright thanks for the help.

i will post my finished project as soon as i get it done :lol: