My first gun using QEV 20bar

GustavssonB · Wed Aug 08, 2012 2:23 pm

I made a simple test today whith a blowgun as a pilot valve for the QEV, and the result was better accuracy but the gun lost the clean look:(

Does anyone know a simular valve but is more compact and has a cooler look?

Wed Aug 08, 2012 2:52 pm

Thanks everyone for the positive respons:) yes the chamber is little big, I have been thinking on making it semi-automatic but I still haven't found a clean design for it but i'm planning on it:)

Punch or drill a SMALL hole in the QEV's piston between the valve seat and the outer rim.
(Do not puncture the section that seals off the out-port or it will leak and stay clear of the edge to avoid tearing).
Put a weak spring behind the piston to help it return ( or rather stay shut while tank is filling) and turn your blowgun around so it can handle higher pressures.
Gently tap the trigger for multiple shots.

That's the easiest way and cheapest too.

Does anyone know a simular valve but is more compact and has a cooler look?

I think I do:
As you seem to be able enough judging from the fittings you have made/ adapted...I would suggest you replace the blowgun entirely though.
make your own hammervalve, trigger and hammer.

That is exactly what I did here:
http://www.spudfiles.com/forums/old-sha ... 17827.html
Read all pages to see the progress.

Not so sure about the cooler look though..

BTW: with a well made hammervalve all your components should be able to handle 20 to 25 bar.

Zorlord · Wed Aug 08, 2012 8:40 pm

If you could fabricate a wooden body for it, just spray everything brass/ silver and youd have a neat steampunk themed pistol..

silentkill12345 · Thu Aug 09, 2012 5:44 am

replace that tire blow gun with one of these

http://www.benl.ebay.be/itm/6PC-Air-Blo ... 41690731d3

Here is an example of what it could look like with your QEV

http://www.spudfiles.com/forums/25-air- ... 22941.html

GustavssonB · Thu Aug 09, 2012 12:48 pm

Thanks for all the good tips Brian the brain, but I didn't really understand how to make the Gun semiauto by just modding the QEV, don't you need 2 air tanks for that?

BTW: with a well made hammervalve all your components should be able to handle 20 to 25 bar.

Are you sure about that man, on the website I bought the QEV it said 0,3-8bar...

If you could fabricate a wooden body for it, just spray everything brass/ silver and youd have a neat steampunk themed pistol..

Yes it would be awesome to make it a steampunk design for it, but it will take a while before i´m starting with that:)

replace that tire blow gun with one of these

http://www.benl.ebay.be/itm/6PC-Air-Blo ... ompressors -1-4-BSP-Garage-and-Workshop-Tools-/280934953427?pt=UK_Air_Tools_and_C ompressors&hash=item41690731d3

I´m not a big fan of that design, it must be because u can find it on almost every gun with a QEV:( but thanks for the tip:D

Mr.Tallahassee · Thu Aug 09, 2012 3:26 pm

GustavssonB wrote:Are you sure about that man, on the website I bought the QEV it said 0,3-8bar...

That is the operating pressure. Companies intentionally leave a very large margin of error for safety. People have used these up to pretty high pressures before. If you aren't sure, test it from a safe distance. If you think about it, 1/2 PVC pipe has a working pressure just under 25 BAR. The bursting pressure according to this chart here would be 1910 PSI or about 132 BAR. That rating is most likely a way to keep them free of lawsuits about exploding valves due to overpressure.

Spud Destruction · Thu Aug 09, 2012 9:36 pm

That thing is crazy looking hahaha nice..

silentkill12345 · Fri Aug 10, 2012 4:41 am

replace that tire blow gun with one of these

http://www.benl.ebay.be/itm/6PC-Air-Blo ... ompressors -1-4-BSP-Garage-and-Workshop-Tools-/280934953427?pt=UK_Air_Tools_and_C ompressors&hash=item41690731d3

I´m not a big fan of that design, it must be because u can find it on almost every gun with a QEV:( but thanks for the tip:D[/quote]

Treu, but you get a much cleaner look than with this blow gun...

Fri Aug 10, 2012 5:02 am

Thanks for all the good tips Brian the brain, but I didn't really understand how to make the Gun semiauto by just modding the QEV, don't you need 2 air tanks for that?

Short answer:
No.
Without the mod you do.

It will enable the valve to reset rapidly after the pilotvalve closes.

This means you can get multiple shots out of a single reservoir as far as the QEV is concerned.

The final function is then dictated by the pilotvalve.
Safety pop-off will give you full auto, a hammervalve will give you seperate shots, a ballvalve pilot would still only give you one single shot.
How you hammer the valve determines the rest.
Autocock system ( by using an air-ram for instance) in full auto or semi-automatic design, ....or just a handcocked repeater.

GustavssonB · Fri Aug 10, 2012 5:02 am

I'm going to replace it with a slide valve:) to make it semi auto

Fri Aug 10, 2012 5:09 am

Too bad we posted at the same time.

BTW:

If you were to have a slidevalve empty the pilot into a small capped-off section of pipe it would still function semi,but with minimal waste of air and without the need for an extra reservoir.

You should do what you're comfortable with, I'm just pointing out the possibilities.

If you'd do the eq. hole the right way it won't effect the valve other than add possibilities.

GustavssonB · Fri Aug 10, 2012 5:16 am

Dude, thanks for all the good tips!:D I'm going to experiment with the Gun, and see which way that makes me happy:)

slugguy · Fri Aug 10, 2012 12:00 pm

Looks very nice. Do you have any idea what velocities you are reaching? What is the barrel made from and what diameter did you go with inside the barrel?

GustavssonB · Fri Aug 10, 2012 12:04 pm

slugguy wrote:Looks very nice. Do you have any idea what velocities you are reaching? What is the barrel made from and what diameter did you go with inside the barrel?

Thanks:) I have no idea how strong the Gun is but it's Pretty powerfull:)
I'm using a copper pipe as barrel with 10mm in diameter inside, and shooting steel balls that fit perfect:)

slugguy · Fri Aug 10, 2012 7:41 pm

Brian,

"No.
Without the mod you do.

It will enable the valve to reset rapidly after the pilotvalve closes.

This means you can get multiple shots out of a single reservoir as far as the QEV is concerned."

Can you explain the hold in the cylinder a little more, maybe add a picture or something. I just got the exact valve in the mail today and I'm interested in making the modification. Thanks![/quote]

My first gun using QEV 20bar

Do I dare to take it up to 15 Bar?