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Posted: Wed Jun 29, 2011 9:26 am
by Spooky
Crna Legija wrote: I doubt you will notice any power gain/lose but better of going with the tee if you can get a peace of all thread that way the chamber will be closer too the barrel.

Yeah, after the join in question I'm going to use two angled 45 degree fittings to bring the chamber directly under the barrel so that's not really a factor.

I just wasn't sure what sort of effect the 'fighting to escape' issue from the T would have. The T fitting looks better anyway so I guess I'll go with that.

Posted: Wed Oct 12, 2011 1:50 pm
by Goats spudz
Will hydraulic couplings work for pneumatics because my dad has LOTS! of hydraulic stuff at his work? http://www.airlines-pneumatics.co.uk/we ... ode=T02009

Posted: Wed Oct 12, 2011 5:29 pm
by saefroch
Yes, so long as they have compatible threads. Hydraulic fittings are typically designed for very high pressures, inquire as to the pressure rating.

Posted: Wed Oct 12, 2011 6:33 pm
by Zeus
But remember that hydraulic oil is thicker than air, and a seal that works for oil may not hold air very well. Same as hydrogen or helium can leak through pneumatic seals.

If you don't mind slight leaks, then it'll work fine.

Posted: Wed Oct 19, 2011 7:57 pm
by Gun Freak
Will I need a spring to close this hammer valve, or should the pressure alone close it? Note the trigger is not drawn yet, just look at the valve part.
Image

Posted: Wed Oct 19, 2011 9:12 pm
by mattyzip77
I have recently just started studying hammer valves, however I think the pressure alone should be enough.

Posted: Wed Oct 19, 2011 9:34 pm
by Gun Freak
I think the pressure will close it, but without a spring too much air is wasted.

Posted: Wed Oct 19, 2011 10:34 pm
by Mr.Tallahassee
Whether or not the air is wasted depends on the length of the barrel. Pressure plays a part in dwell time also.

Posted: Wed Oct 19, 2011 10:39 pm
by jackssmirkingrevenge
Mr.Tallahassee wrote:Whether or not the air is wasted depends on the length of the barrel. Pressure plays a part in dwell time also.
This is why it's vital that spring length/travel and possibly hammer weight can be altered in order to tune the mechanism.

Posted: Wed Oct 19, 2011 10:54 pm
by Mr.Tallahassee
Maybe you can use an external spring on the valve. You can get butterfly springs and test different tensions and adjust striker distance as well. The spring will also act as a stop in case the striker hits hard enough to fully unseat the acting part of the valve.

Posted: Thu Oct 20, 2011 10:31 am
by wyz2285
you need a spring, it won´t close. one hammer hit, once the valve is open, all the air will be gone and the valve stem will go in to the chamber. (that´s what I call say from the diagram, if the actual valve is different I don´t know)

Posted: Thu Oct 20, 2011 10:55 am
by pneumaticcannons
hey guys new Q
Im thinking of making a semi auto airsoft gun with a simple T mag. I had an Idea that If i make a little hole at the top of the mag so when I shoot one bb the rest in the mag get sucked up the mag until the air is cut off then they fall back down and the cycle repeats...

tiny hole drilled here at the top
knvnkjdnkj./\
knvnkjdnkj|o|
knvnkjdnkj|o|
knvnkjdnkj|o|
knvnkjdnkj|o|
knvnkjdnkj|o|
--------------o------------
----------------------------

ya you get the point. :D I figured that This would waste about the same amount of air as a simple blowback system. so any way, would this work?

Posted: Thu Oct 20, 2011 11:33 am
by Mr.Tallahassee
It would work if the airsoft BBs were a fairly tight fit in the mag but you couldn't have more than a few dozen shots without a very long mag. I wouldn't worry about pushing the BBs up into the mag so much because even when the mag is sealed the pressure pushes them up. I would say use a small detent in front of and behind where the mag attaches to keep the BB from rolling out.

Posted: Thu Oct 20, 2011 12:53 pm
by wyz2285
there will be double feed, when the air pass from the barrel, it creates a vacuum efecte witch sucks the bbs from the mag to barrel

Posted: Thu Oct 20, 2011 10:13 pm
by pneumaticcannons
hmm youre right wyz2285 I forgot about the Venturi effect so unless the burst of air lasts > or = to the amount of time the bb takes to exit the barrel It would just suck more in... i guess ill just take Mr.Tallahasse's advise and make a small hopper hopping the pressure will push the bb's up even with a sealed mag.