SpudFiles

[quote="Lex] It`s the lack of proper tools, experience, space and money that keeps me from trying. [quote]

tools: tools what tools? a drill, hammer maybe, some sand paper? probably a ruler and a pen? the only thing you probably dont have is glue.. and thats not super expensive...

experience: you will never gain experience without trying anything,

space: build a prototype, a smaller version.

money: if i can build thisthis for $25

and like jsr pointed out if Ant could build that for under 20 was it?

i think you can build at least a prototype...
ahh look you got me ranting again

POLAND_SPUD wrote:uhmm but the spool could itself could be the bolt that loads new round

also dwell time would be improved as pressure would act on it as soon as it opens

Isn't that essentially a triggered version of this?

well it is similar... now that I look at it I realize that your idea could probably work with higher pressures

I've been thinking about a design similar to this one when I was trying to design a simple to manufacture high pressure valve... you know the one that ideally should combine both the valve and a loading mech into one block of alu

If I were to build it though I would rather use air instead of the spring ( fed via a simple 3 way valve for full auto or a pulse valve for single shot... of course either of them would be feed with regged down air)

Ahem..In the proposed first picture, pressure will drop the instant the ammo leaves the barrel, closing immediately afterwards.

I have experimented with this stuff enough to tell you it will not be gushing out air.It will close.
the hole through the middle is an interesting idea as it will close the valve even earlier.
In my opinion it will save air but it will also give less power.

In fact..the first picture is the best.Ammo gets full flow up till the muzzle and the valve will still close fast enough to trap the air in the reservoir to enable multiple shots.

it is in actually pretty much the same as the push button valve.
Wich I fired with ( okay, a large caliber) barrel and it just popped..
It had no trouble sealing.

I wonder when someone will scale it up and make a 1" porting hammer valve suitable for any pressure the material will handle...

Psy...?? feel like machining another piece??

Sure... but first I will machine a few snapvalves... next week or so. Actually wanted to do that last Monday but I had other things on my mind.

I figured that..

I'll come by jan 31st..I'm passing your place on the way to my inlaws..
I'll bring the tanks...And I'd like my taps in return..


And to stay on topic:
I'd also like my pushbutton valve back so I can test this some more...
Maybe turn it into something nice.... .177 blowback or something...

well yeah push button valves, spool valves,QDVs, hammer valves... if you think about it there is hardly any difference between them and they are all pretty much the same

psycix wrote:Actually wanted to do that last Monday but I had other things on my mind.

Did you get new socks for Christmas

jackssmirkingrevenge wrote:

psycix wrote:Actually wanted to do that last Monday but I had other things on my mind.

Did you get new socks for Christmas

From my parents I got nothing, but from my work I got a package with a lot of food and a bottle of wine, which is, empty now (of course).


Haha BTB, it looks like every time you go to your inlaws you pass by here... is it so horrible there that you need some spudding-time to compensate?

Hmmm....... this looks like your trying to overcome a problem that just isnt there.

Hammer valves dont take that much force to open. On my gunpower stealth, I only need a light spring and a 60g hammer to fully open the valve at 3000psi

at 100 or so psi im sure i could open it by just tapping my finger on the stem.

Dave

Huh?
Just took a look at this schematic. I`m not aware of the dimensions of the valves head, but let`s assume its diameter is 5 mm. At 3000 psi there should be roughly 40 kg of force holding it shut. But with a hammer of 60g and your light spring being able to open it... Well..
This confuses me Could one of you explain this?

Hmmm....... this looks like your trying to overcome a problem that just isnt there.

The problem isn't in the high pressure, it is in the force this pressure generates over a large surface.

We need large flow to fire large diameter ammo at high velocity.
This requires a larger valve.

My hammervalve at "only" 850 psi was impossible to tap open...except with an actual hammer....I had to hit it hard too.

This idea of balancing out the valve ( who did that first..??) overcomes those problems in a simple way.
The problems you don't have in your commercial 3000 psi airgun.Wich I can outdo with my homemade 700 psi airgun.. when it comes to power.

Surface area versus pressure.
A mix of both is even better...

Brian the brain wrote:
This idea of balancing out the valve ( who did that first..??) :

Brocock cartridges have been around since the 1970's.

I'm sure there are other examples if one looks hard enough.

Your 40kg force woud be static weight. However the hammer in in motion which means momentum will have to be taken into account.

What kind of pressures would you be using? and what diameter barrel?

Dave

Prototyping is on schedule for the next week or so. The barrels diameter should be at about 5 mm, pressure is limited to about 130 psi due to my crappy pump

I`m aware that at these pressures there is no real need for a highly specialized system, but it`s for the joy of brooding