Easy hammer valve with GREAT results

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
Dave_424
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Hey guys, I have always wanted to make a hammer valve, so I knuckled down and did it!

It is sooooo simple, you get a female quick connect, remove the collar and the locking ball bearings.
Now, attach the end of your barrel to a male quick connect.

Basically done - When the male quick connect is pushed into the female one, it lets air flow the barrel

I have just added a few bushings and springs to that when the barrel is pulled forwards and let go, the male quick connect pushes into the female one, letting a short burst of air down the barrel.

And the power is there, doing the "Poor man's chrono" I managed to shoot trough the bottom of the can, it then carried on and went through the top. airsoft fans will know that just through the top means 500 FPS+ so my HUGE guesstimation guesses around the 700 - 800 fps mark

What do you guys think?

Dave
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Gippeto
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Sounds remarkably similar to this, :wink:

http://www.spudfiles.com/forums/modifie ... ter,0.html

How about some more specs? (Barrel length, pressure, approximate spring force (at both barrel positions) etc.)

Edited for spelling.
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Dave_424
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Sorry, didn't see that topic

Berrel length is 90cm it is 8mm steel with 1mm walls, this means that if you hold it vertical, put a bb in the top and put your finger over the top, it takes about 10-15 seconds for the bb to get to the bottom of the barrel

Pressure is 150 psi

spring force at rest is just more than nothing

No idea about at the other end, the spring is a guarder 150% recoil spring for a WE or TM hi capa 5.1 not really a strong spring

Out of 50cm of hydraulic hose (approx 1/4" to 1/8" ID) I can get about 5 shots from 200 psi to 100 psi. Using about 20 psi a shot

Dave
Last edited by Dave_424 on Mon Feb 09, 2009 1:02 pm, edited 1 time in total.
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Gippeto
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Sounds pretty good so far. :)

Have you seen the Airforce Stealth? It uses a "transfer sleeve/breech cover" around the barrel which is struck by the hammer (also on the barrel) to open the valve.

This would allow the barrel to remain "fixed" and might lead to improvements in accuracy. (If you're headed that way.)

Opening the breech, cocks the hammer.
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airforce stealth valve drawing.gif
airforce stealth valve drawing.gif (4.24 KiB) Viewed 3632 times
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Dave_424
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Thanks, I had posted that diagram in another topic, I might have a go at making something like that, hmmmm.......................

Dave
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ALIHISGREAT
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Please post some pics!!!! how are we supposed to worship your craftmanship without pictures of your creation? :wink:
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dudeman508
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If only i had a hammer valve to go with thishttp://www.spudfiles.com/forums/10-seco ... 17004.html i put electrical tape around the screw so now it seals enough to not leak much when i open the valve
Dave_424
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no pics ATM, Might be able to put some up tomorrow.

This is because I have now dismantled the gun and am thinking of a way to make the same mechanism in Gippeto's post

Stay tuned guys :P

Dave
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Mr.Sandman
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sorry but ive seen so many posts about mods to this fitting aand i was wondering how do you remove the collar on the quick connect?
Yeah, it's that important.
Dave_424
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mr sandman, the front lip part that the collar is pushed up against, put that in a vice and put a spanner on the bit behiend the collar and unscrew it

However the sear broke and the launcher proceeded to fire a 0.2g bb into my hand.

Yes.... INTO!! my hand, the gun fired unexpectically and because my hand was infont of the barrel (I know, I was putting another couple of bb's in for a shotgun effect) it embeded the bb into my hand.

My hand was on a 45 degree slant to the barrel which meant that the BB broke through the skin, went in about 4-5mm and travelled up my hand under the skin about 1cm, I quickly rubbed the BB bobble downwards towards the entry hole and managed to get it out, My hand swelled up pretty big.

To get rid of any bactreia, I doused it in some jack daniels and had a couple myself (Maybe some more....... quite a bit more) to sooth the pain, A couple of days later my hand has a good amount of bleeding under the skin but is healing well.

From now on I will b alot more cautious with the muzzle end of my launchers, Even though I am EXTRELMEY cautious, honestly...... If I have to go downrange if the target blows over, I relase all of the pressure in the launcher, place it on the ground pointing the opposite way and go downrange

I have now dismantled the gun but might still re-build it later

Dave
Dave_424
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Here - the broken skin is where it entered
Image
maggotman
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ouch good job it hit at 45 because it might have been harder to get it out.
Dave_424
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Yeah, could have dug in pretty deep

Woah, My hands look in pretty bad shape :)

Dave
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Dave_424 wrote:If I have to go downrange if the target blows over, I relase all of the pressure in the launcher, place it on the ground pointing the opposite way and go downrange
Alternatively, the gun could go down range with you. If I have downrange problems, I safety whatever I'm using (because everything I have is built with at least one safety) and take it with me while I'm fixing said problem. That means I can always have it facing downrange, but am at no risk of hitting myself, either.
Does that thing kinda look like a big cat to you?
Dave_424
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Yeh, that is a good way but is hard for launchers with huge tanks/really long barrels ect.

Dave
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