M4 SOPMOD airgun/replica

[FighterAce]

I did some research, called a few stores and got to the conclusion that QEV valves are not avalibile in my country at all. I was suspecting this while getting parts for my homemade QEV. I asked if they have something like it but they didnt even know what QEV is so I'll have to find a way to make my own work...
Is there any troubleshooting post I can check to find my problem?

[jackssmirkingrevenge]

Is there any troubleshooting post I can check to find my problem?

You're in it, ask away some details/diagrams of what you did would help

[FighterAce]

Well.. I used this tutorials to make my first experimental QEV...
http://www.youtube.com/watch?v=apSA_ny8DgM
http://www.youtube.com/watch?v=vmxaI3_S ... re=related

Instead of a male 1/2 tee I used a female 1/2 tee and 3 connectors because there weren't any and instead of grease I used mechanical oil to lube the hot glue piston. I think that's why the piston moves very hard inside the 3/4 connector and its sticky to the touch. As the air tank I used a 0.5l coke bottle because I had no PVC pipes on hand and it was the closest I could get to the amount of air it would get with a PVC air tank. For the plot valve I used a 1/2 ball valve but I'd rather use a schrader valve and make an internal spring system to press it if it would be too hard directly using the trigger.

I checked various rifle designs like P90, Tavor21, CX4, G36K & G36C and none seem like a good candidate for a homemade QEV. The homemade solution is way too bulky. Is there any other QEV design that's smaller and a bit more compact? I might also switch to all 1/2 parts to save weight and space but I don't know how this will affect the performance...

[POLAND_SPUD]

so where do you live? if in AUS then, yes you might have some problems with getting QEVs

but QEVs can be difficult to find so it might be that there are cheap QEVs in you country but you couldn't find them

[jackssmirkingrevenge]

If you're handy with epoxy adhesive, you could easily make your own, maybe scale up something like this.

As to using a schrader as a pilot,I've done it with a 1 inch piston.

[maverik94]

If you're handy with epoxy adhesive, you could easily make your own, maybe scale up something like this.

AHA!!!!!!!! I think it's clear that JSR must be recruiting people for his soon to come "Epoxy Revolution". Careful FighterAce!!!!!!

[jackssmirkingrevenge]

I think it's clear that JSR must be recruiting people for his soon to come "Epoxy Revolution"

That's no secret, I've been an Evangelical Epoxist since the SpudTech days

[FighterAce]

no worries... 2 weeks ago I had no idea what epoxy was so dont count me in for that
as for the piston I'll rather use a wooden dowel...

EDIT
can you use pvc pipes for the piston body?

[jackssmirkingrevenge]

can you use pvc pipes for the piston body?

You can use endcaps...

[FighterAce]

can you use pvc pipes for the piston body?

You can use endcaps...

nah there are no end caps that small... I'll stick with the dowel
I'm just not sure when you make that small slit to let the air pass on the piston body, do you cut a notch in the rubber gasket too?

so where do you live? if in AUS then, yes you might have some problems with getting QEVs

but QEVs can be difficult to find so it might be that there are cheap QEVs in you country but you couldn't find them

I live in Zagreb, Croatia...if there are no QEVs in the biggest hardware store in the country then there are none at all believe me

[POLAND_SPUD]

I live in Zagreb, Croatia...

SLAV POWER!!!

biggest hardware store

QEVs are normally used to vent single acting air cylinders and are normally sold only in shops selling pneumatic stuff...
you won't find them in a hardware store

[FighterAce]

I live in Zagreb, Croatia...

SLAV POWER!!!

biggest hardware store

QEVs are normally used to vent single acting air cylinders and are normally sold only in shops selling pneumatic stuff...
you won't find them in a hardware store

well I dont literally mean hardware store... hardware stores here and in US have a completely different meaning.. and they do have penumatics. I've searched A LOT for that dedicated store and found Nothing

[POLAND_SPUD]

they do have penumatics

do you mean stuff such as blowguns & air tools or manually actuated indirect acting 5 way spool valves?

you need to find a real shop selling pneumatic equipment used in industrial automation and stuff like that
sorry but I just want to make sure you understand where you can find it

do you know what they are called in Croatian ?? I couldn't find QEVs here in Poland as here they are called 'zawory szybkiego spustu'... so when I typed QEV in google I couldn't find them

don't assume that it's just a direct translation of QEV into Croatian.. it might not be that simple


well if you can't find a shop then you might order them off ebay or from abroad

[jackssmirkingrevenge]

'zawory szybkiego spustu'

Sounds like it could be used in a pickup line

[FighterAce]

yes we call em "pneumatski brzoispusni ventili"
but you gotta understand stores are pretty limited here.. even when I google it it aint showing me what I want... I even get results in russian

the only thing I found was this schematics.. witch is in Croatian btw
here take a look yourself http://www.gardenos.hr/pneuind5.html
look for "brzoispusni ventili" and when you look at "radni tlak" witch means operating pressure it goes from 2-10 bar and thats pretty bad if I ever get a pump that can go over that

so.. I got almost everything set up for the QEV just need to find a wooden dowel and drill another hole in the metal end cap for the 2nd schrader valve

EDIT
is it possible for a homemade QEV to take 30 bar?