"In the world of spuds today"

[Zeus]

P doesn't need a chamber, it needs a source of air, be that a bike pump, a beer fart or a HPA bottle. You fill it, remove it and it'll fire.

[farcticox1]

I think this might work with the slide valve open the chamber will fill through P, went it vents the QEV will operate, when it closes again the pilot air through the non-return will make sure it seats closed again hopefully before the chamber empties

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That's how it works in my head

I would still recommend one of theses as a trigger valve, a 3/2 with 3 ports, it's basically a ready made QEV trigger

[Air2theBrain]

Thanks for the replies guys much appreciated.

F1 that drawing looks exactly what i put together, but the fill point is on the opposite side..?

Does the QEV need to be modded for that to work?

The trigger looks good, but when i google search/enter-3/2 trigger i can't find it anywhere, would you have a link by any chance?
I entered pneumatic 3/2 trigger and i simply can't find it sorry...it must have a differen't name..?

Quick question-Can a QEV still be used if the diaphram/valve can no longer be used?
Both of the valves have holes in them, i realized i had the hole in the wrong position, so i drilled a hole in the other one which i thought to be the right location but that never worked either.

[Air2theBrain]

Ruined 2 more QEV's, but these smaller qev's are VERY weak, cheap pot metal.

Only air leak both times was on A, could never tighten it enough, and the photos show the result.

I wont be using those anymore...i couldn't believe they broke like that, wouldn't accept 100psi, it stopped leaking at around 50psi.

4 QEV's ruined...



free share picture

[Air2theBrain]

Went back to my old QEV and never had a problem.

Not sure if my brass fittings didn't like the other QEV's...but the one pictured never leaked once, filled her up to exactly 350psi and the sound that came from it was rather intoxicating..

I realized i can easily make a compact cannon with 2 chambers.

Shout out to JSR who mentioned using a 88g Co2 cartridge on another thread. 8)

Was fun watching that turn to ice after lightly tapping the seal with a nail, drill and tapped the holes for the foster and air gauge, and will happily take 900-1000psi.

The next one will have the air gauge at the front of the air chamber so there's no dead space.
The chamber pictured was for testing...does anyone know if that chamber would be ok for a 12" barrel?



photo upload sites free

[farcticox1]

wow, that's some poor chinesiem, the black block ones are pretty good, my 3/8 one was about $6 from Ebay. Sure someone here has tested these to failure to some really high pressures

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If my circuit works the QEV can be standard, as god intended. But there must be a non return to make it seal when filling.

If you are near a Princess Auto they do a really nice 3/2 3port valve (roller lever valve)
https://www.princessauto.com/en/detail/ ... -p8192437e

Here's a nice one on Ebay
https://www.ebay.ca/itm/Air-Pneumatic-2 ... Sw2xRYRh0O

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[Air2theBrain]

Ah thats awesome many thanks F1.

Do those triggers give the same performance as a 3-way/slide valve?

Yeah i was very surprised they broke so easily, but personally i think i may have over tightened them..but this is the first time ive filled to anything over 100psi, the air pump is great for finding any leaks in the cannon thats for sure.

Oh i realized the Palmers regulator i can use..but needs to be set up differently, was especially for paint ball markers, i will get the one that was actually recommended to me by a member here, the 0-700psi one. The reg i have now is rated to 400psi.

I want it to shoot between 150psi-300psi.

If the main tank is filled to 1000psi, would that give her around 3 powerful shots@300psi?

[farcticox1]

those lever valves are fine for triggering QEVs, 1/8 Npt ports should be big enough, keep the connections between the 2 as short as possible and small diameter so there is not too much volume to dump. I use 4mm OD air line, so it's 2.5mm ID, that would not take 1000psi though

[Air2theBrain]

Im not a fan of air lines...lots of dead space and i will be using pressures over 300psi once ready.

[farcticox1]

This guy got it sorted

[youtube][/youtube]

[youtube][/youtube]

[Air2theBrain]

Nice i like Swan Donovan, he has some very powerful cannons. 8)

I was simply struggling with building a single chamber cannon..getting the qev to work was impossible for me..i even tried once more yesterday and of course nothing..wish i knew what on earth i did wrong...

I have the trigger sorted for the 3-way valves anyway...was just the qev which are the bane of my existence..or rather were, ive put that way behind me and wont be going back there...after a week of trying im just no bueno..

Latest project is going well though.

wan

EDIT-Swan's trigger set up is different..is that like the one you use, it has 3 ports, but one port vents to atmosphere?

The QEV video was helpful...my spring was no where near as big as the one he uses...

[farcticox1]

yes he used the same trigger valve, his variable exhaust was a neat idea

[Air2theBrain]

yes he used the same trigger valve, his variable exhaust was a neat idea

Yep it works a treat, i need to watch more of his videos.

Seeing light weight bb's embedded into that timber board was impressive, he had me thinking back to my last airsoft plinking session...but never had enough power to put them in that far, hope he does a chrono reading soon.

The .22 hollow points at 600psi was impressive.

[Ragnarok]

Not exactly an earth shattering bit of news, but after Joerg posted a review of a Chinese knock-off of the FX Airguns pump, I figured that the price was low enough to take a gamble on rather than just "one day" assembling the pile of pipe in the corner into a new pump.

I'm waiting on some proper fittings so I can swap my projects over from Type 21 to QC02 connectors, but the box included a Schrader adaptor that I've put together a fitting for in the meantime. (Initial impressions are fair. For my purposes it'd have been nice to have had a bit more volume and a bit less pressure, but it's still entirely acceptable for the job).

Now I've got a pump that should be able to reliably hit 40 bar, I might actually have an excuse to finish building Timberwolf.

[Zeus]

Myself and JSR have had them for a couple of months, I've done a couple of pressure tests on QEVs (check the recent posts in this thread). And can I recommend a 3kpsi pressure washer gun plinker. More satisfying than you think.