mini hammer valve

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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Sticky_Tape
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Mon Mar 23, 2009 6:24 pm

Maybe you should go with blow forward again jack. Just to avoid ammo feeding problems. Definetly would be promising with blowforward! Almost a sure thing.
You can tell how awesome a cannon is by the pressure used.
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jackssmirkingrevenge
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Mon Mar 23, 2009 6:40 pm

I doubt blowback or forward would be practical on such a small scale.

I was thinking of a side feed mechanism like this (viewed from the front as a barrel section) The dark grey plunger would be connected via some sort of cam to the pop-off piston, pushing a BB into place at the moment of firing while blocking off the magazine.
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sidefeeder.GIF
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psycix
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Tue Mar 24, 2009 12:34 pm

I think your plunger's shape should be: ( instead of )

Blow-sideward valve lol.

Dont forget that the pressure may push the plunger back.
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jackssmirkingrevenge
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Tue Mar 24, 2009 12:35 pm

psycix wrote:Dont forget that the pressure may push the plunger back.
Not if the pop-off piston is mountad sidewards and the plunger is directly attached to the piston ;)
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JDP12
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Tue Mar 24, 2009 1:07 pm

I don't think blowforward would be very good on full auto. As JSR has already proven, its great on a semi scale, but I don't think it has the potential to be full auto.

Then again, when have I been right :roll:
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POLAND_SPUD
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Tue Mar 24, 2009 3:03 pm

I had an idea for something similar.. IMO it's the best possible way to load ammo since it doesn't restrict flow... (ofcorse the plunger should be longer than it is now)

I had some problems with flow restrictions casued by bolts and my conclusion is that blowforwad bolts will work but they won't give you good performance...

this seems to be esspecially problematic for smaller guns as it's more difficult to build a bolt creating as little flow obstrucition as possible when you scale stuff down

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ALIHISGREAT
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Tue Mar 24, 2009 3:24 pm

its a theoretically good idea Poland, but the problems from my point of view are the complicated mech, and relatively large and complex magazine structure (the whole thing including ram and hopper etc.)

so we need to think outside the barrel and gun...
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Brian the brain
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Tue Mar 24, 2009 4:11 pm

A blowback bolt, blow forward bolt, a blow sideways bolt and now a blow upward one.

I suggest a blowdown bolt.
Damn...that would be gravity fed.


Why not feed the ammo straight from the back and have the airfeed from under.Through a Tee.


@ Jack..I understand how you feel buddy.
Face it...full auto is a female dog.

Why not just go with the ultimate inline design, but with this pulsing valve to save gas?
No parts to break, chop, and cease up.
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
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POLAND_SPUD
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Tue Mar 24, 2009 5:39 pm

@ BTB jack has always wanted to achieve full auto by creating a mechanism that would both act as a main valve and as a bolt.. so in his designs it's always the bolt that dictates ROF... IMO it's a little bit too ambitious... but I agree with you BTB - if he really wants to he can save air by adding an o-ring or a tube that would lallow pressure to build up before firng each BB

@ali well It shouldn't be that difficult to build it.. in fact you can build it all with a regular T, a 45deg tee, the plunger and an air cylinder...

I suppose it's as simple as it can be from practical point of view as you don't even have to have good manual skills to build stuff.. all you have to do is to join several parts toghether

if you have a look at this thread you'll find out that the design is very simple and there are few things that can go wrong...

naturally when you want to switch to a semi or full auto you can expect added complexity but instead of putting complicatd tiny mechanisms that have to be created preciselly to work (so designs that can be compared to an m16 rifle) isn't it a better idea to try something simple (like an ak47)?

and trust me - hopper is the only way to get enough ammo for a semi... not to mention a full auto
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jackssmirkingrevenge
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Wed Mar 25, 2009 1:07 am

Why not just go with the ultimate inline design, but with this pulsing valve to save gas?
No parts to break, chop, and cease up.
Ah, but that would go against the spirit of what I'm trying to achieve, it would go *braaap* *braaap* *braaap* instead of *dakka dakk dakka* :roll:
I had some problems with flow restrictions casued by bolts and my conclusion is that blowforwad bolts will work but they won't give you good performance...

this seems to be esspecially problematic for smaller guns as it's more difficult to build a bolt creating as little flow obstrucition as possible when you scale stuff down
My thoughts exactly.
naturally when you want to switch to a semi or full auto you can expect added complexity but instead of putting complicatd tiny mechanisms that have to be created preciselly to work (so designs that can be compared to an m16 rifle) isn't it a better idea to try something simple (like an ak47)?
Believe me, I'm not a fan of complexity, but sometimes it's inevitable. It's much simpler to use your feet than to develop a car, but you can only go so much walking.

I know the pop-off piston works, and I had gotten very close to making it work here before the piston decided to die on me and being encased in epoxy, I couldn't service it.

I guess I should rebuild that design (with added servicability features) and go from there.
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psycix
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Wed Mar 25, 2009 8:08 am

Hahah in the thread you linked you said:
jackssmirkingrevenge wrote:
sputnick wrote:Why not conform and use threaded stuff instead of epoxy this time?
HERESY!
Look at you now :roll:
Epoxy is not the way to go with full auto. Its just a sidepath here and there, unless you
I'll try a shot (multiple, I hope) at full auto this weekend, but then I'll start with trying the QEV + popoff pilot and after that a snapvalve.

I believe that the popoff piston design also has a lot of potential. A few modifications here and there and it will be perfect.
I think it would be worth it to rebuild that one, you should do it. I may try it too.
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jackssmirkingrevenge
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Wed Mar 25, 2009 12:20 pm

What, you thought I'd make it out of standard parts? I meant I'd epoxy a threaded section somewhere, actually I'd already thought of ways to make it servicable without having threaded bits :p
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psycix
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Wed Mar 25, 2009 2:54 pm

Sigh... buy a lathe or get some connections.
Custom parts without the messy epoxy stuff, higher quality parts produced with tight tolerances. Its awesome.
Sell that damn jeep and buy a lathe. Will save you thousands of euro's usually spent on epoxy every year!

Or build your own lathe, out of epoxy!
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Ragnarok
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Wed Mar 25, 2009 3:10 pm

psycix wrote:Will save you thousands of euro's usually spent on epoxy every year!
Heck, I think he spent last bought epoxy about four years back, and spent about €80 on it.

My information may be out of date, but I think that's right.
Or build your own lathe, out of epoxy!
Now I'd like to see that happen.
Does that thing kinda look like a big cat to you?
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Brian the brain
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Wed Mar 25, 2009 3:12 pm

Ah, but that would go against the spirit of what I'm trying to achieve, it would go *braaap* *braaap* *braaap* instead of *dakka dakk dakka
*

That's where you are wrong.
Mine shot out only one each time.
Out of a cloud-modded elbow thingy.

@psysix: :shock: Don' t you dare talk JSR out of using epoxy. :? :roll: Well...it's useless anyway...The two go hand in hand. :D

I like the fact he does things differently.Not so long ago Jack and I were the only ones doing stuff the " wrong" way.He's gotten this forum further than anybody...

Jack...two blocks of epoxy, one O-rong and 4 bolts in the corners would make it servicable...
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
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