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Trigger mechanism for a hammer valve?

Posted: Wed Oct 24, 2012 4:06 pm
by Alex345
I've taken the handles off the pilot valve from my previous cannon to turn it into a hammer valve and connected it directly to the 3/4" QEV. But now i need to come up with some kind of trigger mechanism with a tough hammer because the spring inside the hammer valve is VERY stiff...

Here's the old complete valve installed on my previous cannon: http://www.spudfiles.com/forums/my-firs ... 23624.html

And here it is in it's new configuration:

Image

Image

It works great when i hit the valve with a hammer, but i would really like a trigger mechanism of some sort. I've come up with a few ideas myself but if any of you guys have some ideas i'd love to hear them! :D I'm sure the 3 holes from the handles could be used to hold some kind of hammer mech in place...

Don't mind the barrel and chamber on the photo, i'm merely focusing on the valve + trigger mech now, when that's over with i can start thinking about what type of barrel and chamber i'll use ;) Same goes for the 6mm slip fitting which will be replaced with a drilled out male QD fitting.

Oh and another question; I thought that when the pilot air escapes the QEV dumps ALL the air into the barrel? Because when i tap the valve with a hammer it gives a nice and powerful shot of air, but sometimes the chamber isn't empty afterwards... And i don't tap it softly, its a firm hit from the hammer. My current record was 2 powerful shots and one weak one before the chamber was empty.

Posted: Wed Oct 24, 2012 5:31 pm
by wyz2285
Hammer valve plus qev it's a simple recipe for multi shots :wink:
Replace the original spring by a weaker one.

Posted: Wed Oct 24, 2012 11:44 pm
by jackssmirkingrevenge
*cough* Image *cough*

Posted: Thu Oct 25, 2012 5:42 am
by jakethebeast
Yep i get you could get better performance with the slide valve, but if you really want to use the vakve you have take a look at revolver hammers, and the one that BtB made for his multi-pump airgun!

And you should replace the spring, easier to make hammer mech :wink:

Posted: Thu Oct 25, 2012 11:50 am
by Alex345
Problem is that i can't take the valve apart :( And i know about those slide valve thingies, but it was never my intention to build a semi auto cannon. I like full power shots instead of just a puff of air because i often shoot heavy projectiles.

But if i can find a good hammer mech i could build a repeater type of cannon, like a pump action or so.

Posted: Thu Oct 25, 2012 3:29 pm
by archie370
Is that a fire extinguisher piece on that end ... Hahaha

.... Btw what r u asking us it looks like you have answered your own question.

As for your pilot problem, i had the opposite problem i wanted bursts of air and my Qev would dump the whole tank and to fix that on my gun i made a bigger Pilot to open the QEV and shut it again before the reservoir was empty. try making a smaller Pilot and if your pilot can be adjusted try letting out the nut more for bigger shots or instead of using a pilot just use a ball valve if you want one shot

Posted: Thu Oct 25, 2012 6:28 pm
by Alex345
archie370 wrote:Is that a fire extinguisher piece on that end ... Hahaha

.... Btw what r u asking us it looks like you have answered your own question.
My original question was if someone had an idea for a hammer mechanism, and my other question was if it was normal that my cannon could do multiple shots which turned out to be normal with a hammer valve as a pilot ;)

And yes its from a fire extinguisher. Look at my previous cannon, it had a little too much pilot volume yet the valve made the cannon shoot without a hitch so that's why i kept the valve :)
archie370 wrote:As for your pilot problem, i had the opposite problem i wanted bursts of air and my Qev would dump the whole tank and to fix that on my gun i made a bigger Pilot to open the QEV and shut it again before the reservoir was empty. try making a smaller Pilot and if your pilot can be adjusted try letting out the nut more for bigger shots or instead of using a pilot just use a ball valve if you want one shot
I think it fires multiple times because the valve only gets hit by the hammer for a fraction of a second. I don't honestly think my pilot volume can get much smaller than this :) If i could manufacture a hammer mech that's tough enough to open the hammer valve and KEEP it opened instead of bouncing back off, it should work :)

Before this set up my cannon used a solenoid valve powered by a 11.1v battery to vent the pilot, which worked very well actually. But when the pressure went beyond 10 bar the solenoid valve would become unreliable.

Basically what is want to build is a QEV operated 300+ psi cannon (Or big pistol?) which will be fired by the pull of a trigger. So no ball valve as pilot valve for me :)