QEV-75M

[frocksie]

I just finished this QEV gun today, and it is really impressive, even more impressive than my first piston valve.

SPECS
valve: 3/4 in QEV from Fastenal
pilot valve: 3/8in ball valve
barrel: 4 ft of 1/2 in copper
chamber: 3 ft of 3/4 in copper
pressure: 100-150 psi

This gun vaporizes potatoes when shot, so marbles are the best ammo.

This was a pretty fun one to build, and it was my first time soldering pipe.

[rna_duelers]

I like, a lot!Nice damage to those cans.

You could shorten the tube going from the blowgun to the valve and get a performance increase.How much was that 3/4 QEV?

[jackssmirkingrevenge]

You could shorten the tube going from the blowgun to the valve and get a performance increase.

Or mound the blowgun directly to the QEV and add a trigger on a rod extension.

[MrCrowley]

Nice cannon, i've always wanted to use copper. Looks like your soldering turned out good as well, nice job.

@JSR and RNA

The pilot volume is reasonably small, the I.D of the pressure hose is only about 5mm, and that 1/4" galv tee is nothing big either. Though he could upgrade the blowgun for better performance.

[spudgunnerwryyyyy]

His blowgun has a piece of like blue hard foam between the level and the push rod which will make it open more fully, and if you used a 1/4" ball valve for piloting you could take it up to 150psi, the pressure limit for qevs. It would be a bit unwieldy but it would pilot faster and again you could crank the pressure.

[frocksie]

Thanks for the comments.

Has anyone who has used a QEV noticed that when it is opened it makes a ping, similar to the ejection of a clip in an M1 Garand?

Would anyone mind running this gun through GGDT, as it doesn't work on my computer?


I just changed the blowgun to a 3/8in ball valve, and the power increase is crazy. With the ball valve piloting the QEV, I put a nail through a coin.

[origin unknown]

Nice cannon. I like the can damage. Glad to see someone else uses the Fastenal QEVs too 8).

[frocksie]

Thanks, Fastenal was the only place I could find QEVs, so I really had no choice, but they do a good job. I ordered my valve and got it a day and a half later, without paying any extra shipping.

[spudgunnerwryyyyy]

Sweet, so thats great the ball valve helped that much. Did you increase the pressure to 150psi?

[battlemonkey]

is there anywhere you can get QEV's in new zealand? can't seem to find them anywhere. nice gun btw

[hi]

its a cool looking gun, but my recommendation is that you turn the ball valve 90 degrees, that way its like a trigger.

my QEV gun also uses a ball valve for exhaust and trust me, its more comfortable if you turn it 90 degrees. just put a 45 on the nipple and it will do you wonders.

[MrCrowley]

is there anywhere you can get QEV's in new zealand? can't seem to find them anywhere. nice gun btw

Yeah there is, just the one place I know of, they cost a fair penny though.
<A HREF="http://www.rsnewzealand.com/cgi-bin/bv/ ... =nzie">3/4" QEV</a>

If the link doesn't work, go to http://www.rsnewzealand.com and search Pneumatic P4Q quick exhaust valve,G3/4 then look at the first 4 results.

Someone did get one from a hydraulics store, but stock would vary between stores.

[rna_duelers]

I can get them from a number of places,hydraulic places included although they aren't cheap,if they were I'd be using one.

[frocksie]

@spudgunner

yeah, the blowgun couldn't open the QEV fast enough, so the valve was honking. I haven't taken it to 150psi, but I will today.

@hi

I will probably turn the ball valve around today, does it really make that big of a difference?

[origin unknown]

You could mod your blowgun and use that instead of a ball valve.