QEV fill & pilot problem

[evilvet]

Have mercy on me Wyz and Jack & Tech and everyone else who will flame me for this, but I am f#$^&*! if I can find the right post to answer this.

I have an SNS QE04 Quick Exhaust Valve, 1/2" type.
I have an Airtac 3V201-08 NC (note normally closed, not normally open)
This is it here

So....

On the QEV I have chamber on A, breech on R and fill from P pilot.
All as per standard operating procedure.

Is it possible to rig these two valve together such that the QEV will fill the chamber from my compressor and that powering the solenoid will act as the pilot ?

[wyz2285]

Personally I don't like airtac valves, they may leak beyond 10 bar...
However, obviously you can . There is a topic about how to use a 3-way to achieve semi-auto while having only one chamber connected directly on the qev, I'll see if I can find it.

[evilvet]

You sir, are a gentleman.
Thanks

[jackssmirkingrevenge]

Is the solenoid valve a 3 way or 2 way?

[wyz2285]

Is the solenoid valve a 3 way or 2 way?

I believe it's a 3-way

[jackssmirkingrevenge]

In that case, hook up the compressor fill to the solenoid input, and the QEV pilot to the normally open solenoid output.

[wyz2285]

In that case, hook up the compressor fill to the solenoid input, and the QEV pilot to the normally open solenoid output.

He want's to have the compressor at the chamber side of the QEV, witch it's not a bad idea.

[jackssmirkingrevenge]

He want's to have the compressor at the chamber side of the QEV, witch it's not a bad idea.

That's not what I understood:

the QEV will fill the chamber from my compressor

that implies that he's filling the chamber through the QEV, ie through the pilot.

[wyz2285]

Yeah you're right, my bad.
But this it's a good idea, I just wanted to see more implantation of it as myself it's building a semi-auto right now with the same principal, but with machined parts this time.

[evilvet]

@JSR
So if that's the case, the N/O solenoid will allow my chamber to fill form the compressor as if the solenoid was not there at all, yes ?

When the solenoid actions, the N/O port close, sealing off the compressor and the pilot of the QEV is exposed ?

[jackssmirkingrevenge]

But this it's a good idea

In that configuration though, any two way valve can be a pilot.

It's what I had done here with a schrader valve pilot:

[youtube][/youtube]

So if that's the case, the N/O solenoid will allow my chamber to fill form the compressor as if the solenoid was not there at all, yes ?

When the solenoid actions, the N/O port close, sealing off the compressor and the pilot of the QEV is exposed ?

That's exactly the idea, same with any three way valve used as a pilot.

[evilvet]

Well dang it, it don't work.

1.
Air line into NC port.
Trip solenoid
NC port opens and feeds QEV
Chamber fills just like it should
Release solenoid
NC path is closed, pilot vents through the NO exhaust
Chamber dumps out the R port just like it should

2.
Airline into NO port
Chamber fills
Trip solenoid, expecting pilot to exhaust
Instead I get this

Retries hurt from pneumatic field of battle.....................

I can change my plans and add a fill/prime circuit to the microcontroller that runs all this, then have code wrapped around the fire button that recycles the priming, but FFS it can't be this hard.

[jackssmirkingrevenge]

Hmmm... Lets go back to basics. I might have given misleading instructions earlier on.

The solenoid valve has three ports, A, P and R

Circuit open, if you blow into A, it should come out of R

Circuit closed, if you blow into A, it should come out of P

Is this the case?

If so, A should be connected to the QEV pilot port.

R should be connected to the compressor output.

P should be left open to the atmosphere.

[Technician1002]

Have mercy on me Wyz and Jack & Tech and everyone else who will flame me for this, but I am f#$^&*! if I can find the right post to answer this.

Flame wars are against the rules.. I don't do that. Good luck with your project. I've never actually used a QEV, so I'll leave it up to those who have.

[evilvet]

Three ports A, P, R, on each bit of kit.

QEV A is chamber
QEV R is breech block
QEV P is fill side

Solenoid R is compressor
Solenoid A is fill side going to pilot of the QEV
Solenoid P is vented

Chamber fills, evilvet trips solenoid, nothing happens, evilvet considers the merits of tall buildings in the CBD with a high powered rifle.............

If I do it the other way and fill from Solenoid P it works like i said, just requires that extra step to prime then fire on loss of power to the coil.