SpudFiles

he wasn't talking about size - a 3/2 valve is just a 3 way 2 position valve

Oh, so is that trigger good?

Here you'll find more info on 3 way valves >>
http://www.spudfiles.com/forums/directi ... 20438.html

Sure you can use a blowgun as a pilot but you might as well use a QEV + 3 way combo and build a semiautomatic gun

Are they relatively small? They look big xD Can anyone give me a run down on the QEV+3 way combo?I don't really understand it, such as what the hell an actuator is or how to make one of these things

OK, so when its depressed, the air will go nowhere, but when its pressed, the air will travel upwards toward the exhaust ( barrel?) Where does the QEV come in?

is this small enough you don't need the silver thing on the side but makes it a hole lot cooler and every one know cool factor counts

Oh crap, that is awesome... but I'm aiming more for a barrel like that, like a bigger thing. The barrel part will contain barrel, magazine on top of the barrel and air tank below the barrel...look at my really bad drawing xD. The white part will be the actual barrel, the top black part will be a bit smaller and house the magazine, the lower black part will house the air chamber. The whole thing will be 1-1.5 inches wide, and about 6-10 inches long. And also, no, that is NOT what she said.

Also, I really wonder how he made those metal parts...

Anyone help me with QEV+3way valve combos?

What exactly do you need to know?

How do they work? I pretty much figured out how the 3 way works, but where does the QEV come in?

a QEV stands for a quick exhaust valve... We use them as ready made piston valves but in 'real life' they are used in pneumatics for increasing return speed of single acting air cylinders. Notice that 3 way valves are used for controlling sinle acting cylinders, as they can fill and then vent anythign connected to them

[youtube][/youtube]
While you can't see that in the video, because the air cylinder is pretty small, the return stroke on single acting cylinder is slower (this is especially true for large bore air cylinders).

The speed can be increased by installing a QEV valve. It allows air in and as soon as the 3 way valve switches to the other position to vent the air cylinder the piston inside the QEV moves and lets air vent through the exhaust port. Because air doesn't have to travel through the tubing and then through the 3 way, but instead it vents right at the air cylinder thought the large opening of the QEV it vents faster

QEVs are pretty cool valves - but typically they require two valves - one for filling and one for piloting. That's why 3 way valves are so cool - in a way they combine both of the valves into one unit. Thus, they can be used to build a pretty neat semiauto gun. the button is not pressed - the 3 way valve fills the chamber thorough the QEV.

Press the button and it blocks off air supply and vents the pilot side of the QEV - which in turn opens the QEVs and fires the gun
Damn it can't believe I've just spent 15 minutes to explain something that has already been explained

Ohh here you've got an even better vid that explains it all
[youtube][/youtube]

I thought up of mu own..piston/valve thing, drawing diagram now...

wow and I thought I am the guy who draws crappy diagrams

It's kind of hard to guess what you want to build... it looks like an inverted QDV or a spool valve... well if I was right then yeah - it is possible

What is so bad about a 3way valve + QEV combo ?? hmm ?
Ok ok you can build whatever you want

Though if I were you I'd use a slightly different design... one that uses just a barrel with two ports cut in it as both the main valve and the loading mechanism/bolt... I deleted paint from my system so no I can't post a diagram

I drew a really good one on paper, but my stupid printer decided today wasn't a scanning day, and I wanted a diagram up before anybody questions it, so I just drew one really fat on paint.Basically at Nuetral, air goes nowhere, when the trigger is pulled, it pulls the barrel back and it'll flood with air, this motion also loads the next ammo

Also, I'll have to make my own grip and trigger now, blowgun triggers won't do any good here

Where can I get a trigger like this : http://nerfhaven.com/forums/index.php?s ... &show=&st=&

I think that's a Clippard valve... like this:
http://www.clippard.com/store/display_d ... sku=MJVO-3

Gun Freak wrote:I think that's a Clippard valve... like this:
http://www.clippard.com/store/display_d ... sku=MJVO-3

Never seen that before, but great minds think alike