Rattlesnake V3 - HPA auto valve

[jackssmirkingrevenge]

Presenting the third major version of my constant flow automatic valves, following on from V1 and V2. Here's how it compares with the rest of them:



edit: check out the internal diagram and construction details.

Basically the same design, but made in a stainless steel body as it's designed for the 500-800 psi range. Anyway, some videos (all at reg set to 500 psi)

2000 psi fill, fired in bursts:

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2000 psi fill tank dump:

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2000 psi fill tank dump with more spring shims fitted to increase compression:

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Doesn't really come accross in the videos but it's really loud! I tried it with the pellet magazine and total fail, it fired a couple of shots before jamming completely because the heads of pellets in the mag were jamming into the tails of the preceeding pellet and expanding so here's a damage vid with 6mm 0.25g BBs instead:

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Just a quick ten round burst, double feeds galore, but look what it did to that 1/8" thick acrylic (with the BBs being totally pulverised against the hard surface behind it):

[psycix]

Ah finally!
Any pic of the internals?

Are you going to solve the pellet problem?

[Ragnarok]

Well, that tank doesn't last very long, does it?

But nonetheless, very impressive. Good work.

[inonickname]

Man..this is getting more tempting for my overbored PCP project.. I'll post in a min or two.

Yet more good work, sounds insanely loud. The pop-off route seems much more efficient than the blowback route or anything that uses pressure to expand and push something pre-firing.

How long is the barrel btw?

[ALIHISGREAT]

nice, all you need to do now is hook up a propa trigger.

[POLAND_SPUD]

yep... the tank doesn't last very long... do you plan to get a bigger one or do something to increase numbr of shots per fill ? I supposoe that there is some way to optimize the valve to use less air

[jackssmirkingrevenge]

Are you going to solve the pellet problem?

No, the idea is to have the final launcher firing 4.5mm BBs, feeding from a spring laoded tube magazine into a tee breech.

Well, that tank doesn't last very long, does it?

True, though consider it's only filled to 2000 psi (SCUBA tank needs a refill...) when it can take 3000 psi normally, so in practical terms it will last longer. Still, if I'm making this for BBs then the full 6mm porting is very much overkill, I can live with 3mm porting - so I think the next step is to make yet another version with generally smaller dimensions in terms of outlet, piston seat, piston diameter and chamber volume. This should use a lot less air per shot.

The pop-off route seems much more efficient than the blowback route or anything that uses pressure to expand and push something pre-firing.

What I like the most is that no air whatsoever is wasted elsewhere, it all goes out of the barrel.

All you need to do now is hook up a proper trigger

I have some small ball valves on order I also need to make a proper magazine setup but that shouldn't be too hard.

Any pic of the internals?

Exactly the same design as all the other valves, but I've included a detailed diagram of what I used to make it exactly, and included the three epoxy "stages", how the construction was set up and sealed prior to the epoxt being poured.

[pizlo]

Aye, it seems you run that 2000 PSI dry in a mater of seconds. Personally I would want less power over more firing time.

[jackssmirkingrevenge]

Personally I would want less power over more firing time.

I would rather have that too, and I'm not keen on getting a larger bottle because I want a compact PDW type launcher, so as described above I'll probably make another valve with smaller porting.

[ALIHISGREAT]

Personally I would want less power over more firing time.

I would rather have that too, and I'm not keen on getting a larger bottle because I want a compact PDW type launcher, so as described above I'll probably make another valve with smaller porting.

you should just hook it direct to your scuba tank and have the tank your back

p.s. you corrected the spelling when you quoted me you pedant!

[Carlman]

p.s. you corrected the spelling when you quoted me you pedant!

he does that alot

nice work mate she looks sweet!

[Brian the brain]

Still it's got laser sounds...
Would a smaller chamber change your airconsumption...well, not yours, but the valve's...

??


Might just up the ROF again...

Jack, I love your little...thing....

[VH_man]

JSR, Just for an idea, Why not split the whole valve up into two or three parts?

For example, the "VALVE" part, and then the Chamber part, and then the fill area, and then be able to experiment with chamber volumes without having to re-build a new valve.

Once again, Truly Awesome.

[POLAND_SPUD]

though I like some aspects of his constructions I must admit that they lack any servicability or modability

Jack, I love your little...thing....

small is beautiful... but bigger can do more

[jackssmirkingrevenge]

you should just hook it direct to your scuba tank and have the tank your back

Not going to happen

p.s. you corrected the spelling when you quoted me you pedant!

... and I'm not even English. It's a sad day when a foreigner has to correct your native language

Would a smaller chamber change your airconsumption...well, not yours, but the valve's... Might just up the ROF again...

It might change a little but mostly I think that it's smaller porting that will make the difference. After all the chamber doesn't empty after each shot, just lowers in pressure.

Jack, I love your little...thing...

If you rub it hard enough it turns into a golfball auto

Just for an idea, Why not split the whole valve up into two or three parts?

Interesting point

Though I like some aspects of his constructions I must admit that they lack any servicability or modability

While that may be true of some of my prototypes, in this case, the piston can be serviced or replaced, same with the spring, so the crucial parts that one would expect to wear or need adjustment can be gotten to without tearing the whole thing apart.