SpudFiles

Hi, thought I'd ask a question or two after stalking the forums for two years XD

I am currently in the process of preparing to machining some furniture for an airgun, and was hoping to finalize the internals so that I can start CADing. I was hoping to have a automatic feed system, utilizing a magazine and pneumatic piston, to hopefully achieve a moderatly fast ROF when I get a circuit board printed for the automatic activation of a solenoid dcv.

For the airsystem, I was hoping to run a regulated tank of CO2 to a dcv, which would lead to a 1/2 in QEV and a 1/2 in barrel... if that makes sense.

My question is 1) how high PSI can a 1/2 in QEV withstand, and 2) where can a get a solenoid DCV that would stand up to that?

Thanks in advance

Im bot sure about the qev because ive never used one but the solenoid should hold some high pressure. What pressure does the reg get it down to?
you'll be surprised at how much pressure plastic holds, i made a plastic marker gun that stood up to 200 psi no worries

what kind of pressures are we talking about??

how high PSI can a 1/2 in QEV withstand

the so called fastenal qev can handle 400 psi with no problem ... some have used them at 600 or even 700 psi (not that it is recomended to use them at 700 psi )

Standard DCVs are normally rated to about 150 psi...

This one should handle 250 maybe 300 psi though it is theoretically rated to 180psi max
http://www.clippard.com/store/display_d ... -3PDS-D012


Of course there are valves that have higher ratings
http://www.ode.it/Prodotti/26162_31L2.pdf
(from here http://www.ode.it/en-gb/products/genera ... cting.aspx)
But generally speaking higher rating = lower flow

so unless we know what pressures are we talking aobut it is difficult to tell whether you can use a standard pneumatic valve at pressures slightly above its rating or one which really is rated higher but has lower flow/is more expensive

I was hoping to make some custom ammo, about .5 in in diameter and 1.5 in long, made out of steel and brass. Due to the weight of the projectile, i was hoping to run the device at about 3-400PSI, maybe 500PSI if the parts allow.

you can get DCV rated to 500 psi and higher - though as I pointed out earlier they are more expensive than standard stuff and offer lower flow

Would it be possible to get a link to a 500ish psi dcv, and its price. I've been looking for an hour with no luck.

http://www.ebay.com/itm/Ninja-Slide-Che ... 45fd8e1561

good for 3000 psi and less than 10 bucks

This one seems to be rated to 350 PSI
http://peterpaul.com/valves/3-way-norma ... -model-74/

and you can get it here
http://www.ebay.com/itm/PETER-PAUL-SOLE ... 3f0f2e7164


Stuff like this is often cheap on ebay but new ones might be prohibitelly expensive (like 80$ or more). You can get valves rated higher at http://peterpaul.com or just check other comapnies (asco, humprey, parker etc. it isn't difficult to find a valve rated high, but it is to find one that's cheap)

good for 3000 psi and less than 10 bucks

heh you acctualy might be up to something... slide check valve + car lock actuator combo might be cheaper than a proper solenoid valve

well at least you wouldn't have to check ebay regularly to find a good bargain

Hmm, slide valve might be a possibility. I was thinking about either making a Dcv similar to the one in the how-to section, out of milled aluminum. Though after swing that slide valve idea, I might go with that. Would a setup like this work? Qev------t junction------slide valve. With the co2 running into the t. The slide would be actuated by an actuator, like Poland suggested.

Just put the slide straight into the QEV, and the CO2 into the back of the slide.

A slide valve seals the input when activated?

Ocheeboy11 wrote:A slide valve seals the input when activated?

Correct.

Hmm, is there any elegant ways to attach an actuator, electric or pneumatic, to a slide valve?

Eh... Why? A cylinder might work, but wouldn't be elegant to some people. To me it would though

I plan to make this select fire, circuit board running the actuators. Reason this is so complex is that I'm doing if as an interdisciplinary engineering project both for school and for fun. I plan to have another actuator for the feed system, magazine fed.