SpudFiles

POLAND_SPUD wrote:well yeah but that would consume my monthly income

Drink less

for under 50 euros...seems like a reasonable price

... but don't expect finely finished quality for that price either, it would be the "soviet" tovarish-it-works! edition

who said you can't build a pistol in 0.22" calibre?

That's along the lines I'm moving now

is this going to be parte of a hybrid cartridge rifle for the master class challenge

I definitely want to make a cartridge multishot, if it's ready on time then it will be entered.

Looks like you need some sort of stop for the Delrin ring, a slightly smaller OD "O" ring placed in a bored out section of the front ring, but not long enough to make contact with the Delrin until just over full mix pressure.

Mmm but that would then mean it wouldn't seal around the front ring... mmm

al-xg wrote:Looks like you need some sort of stop for the Delrin ring, a slightly smaller OD "O" ring placed in a bored out section of the front ring, but not long enough to make contact with the Delrin until just over full mix pressure.

One option is to eliminate the Delrin ring altogether, but the o-ring will still be compressed by the gas pressure. Still, might give this a go before boring it out for 0.22".

Mmm but that would then mean it wouldn't seal around the front ring... mmm

Tricky isn't it? But once I figure it out, the world will be my oyster having a more or less standardised self contained cartridge system will open up an unbelievable array of possibilities, look at what it did for firearms.

I also want to prototype something along these lines for the pneumatically inclined.

[youtube][/youtube]

Bored it out to 0.22" et voila. You can see the pellet moving across the screen after bouncing off the backstop.

Good:

- tiny (1mL approx) chamber pressurised to 20x

- lead projectile succesfully employed as "valve" sealing against o-ring without the need for a separate valve.

Bad:

- two poorly supported 1mm pins simply won't do

Hmmm...

ummm... threaded steel?

I believe that at 28x mix you just flood the chamber with butane, and pressurize it?

Maybe it would be a nice idea to clamp your cartridges in a small vice, so you can observe it better on video.

I tested my at 10x mix, everything worked perfectly
charged to 15x(only air), the valve still holds the bb, no leaks

Labtecpower wrote:ummm... threaded steel?

Maybe threaded Delrin would seal as per attached, maybe I'm being mindlessly optimistic again

I believe that at 28x mix you just flood the chamber with butane, and pressurize it?

You believe correctly.

Maybe it would be a nice idea to clamp your cartridges in a small vice, so you can observe it better on video.

Nothing really to observe here, the pints tore out of the cartridge body

I tested my at 10x mix, everything worked perfectly
charged to 15x(only air), the valve still holds the bb

Good on you remember you're messing with very high pressures now, be careful!

here's my 5c...


Why not ditch the combustion compressed O-ring, and use a piece of threaded Delrin to compress it?



(too lazy to use autocad)

When loading you loosen the ring, and after loading you compress it and fill it with mix.

hmm assuming the cartridges are to be fired from a chamber (like in a real gun)... you might consider machining them out of delrin only... lol i know it sounds dangerous

Labtecpower wrote:Why not ditch the combustion compressed O-ring, and use a piece of threaded Delrin to compress it?

Similar to this, hmmm...

POLAND_SPUD wrote:hmm assuming the cartridges are to be fired from a chamber (like in a real gun)... you might consider machining them out of delrin only... lol i know it sounds dangerous

While it's the way of the future, I want flying brass dammit!




Still, hmmm...

Similar to this, hmmm...

But I see you had sealing problems..

In the drawing the edges are straight, but maybe you could get a better seal if you put a very light edge on it (pushing the O-ring inwards)

hmm assuming the cartridges are to be fired from a chamber (like in a real gun)... you might consider machining them out of delrin only... lol i know it sounds dangerous

Plastic stays plastic... I like thick metal cartridges

ohh I haven't seen that...

want flying brass dammit!

lol that reminds me of one occasion when I was going to suggest caseless (more like GP-25 granades than this) ammo on one occassion but then I realized you want flying brass dammit!