SpudFiles

zomgwtfbbq wrote:Wow the diameter is 1/4 inch?

External diameter of the body is 3/8"

That's really small!

Yup, the target is to have something in the size range of firearm cartridges

And 200 psi is really sexy.

That would be a 14x mix but I doubt the spark ignition would work at those pressures. In practice I'd be happy with a 6x mix at 75 psi, we'll see this evening.

I didn't expect the friction seal to hold up to 200 psi. This gives me a lot of hope for my own friction seal. When will the long awaited video be up?!

we'll see this evening.

EDIT *** Opps, didn't see that.








EVENING IT SHALL BE (:

zomgwtfbbq wrote:I didn't expect the friction seal to hold up to 200 psi. This gives me a lot of hope for my own friction seal.

It depends on the seal you're using, I had some seals in my HPA BBMG prototypes that held at 850 psi this particular seal I'm using is 4mm internal diameter silicon tubing, I think I had bought it from a pet store, the sort of thing they use in an aquarium, so it shouldn't be hard to find. It is affected by the internal diameter of the seal vis a vis your projectile diameter, as well as how much the seal can yield (depending on material thickness and hardness).

zomgwtfbbq wrote:EVENING IT SHALL BE (:

Don't put your hopes up, but I'm keeping all appendages crossed

update: see! no go with teh sparks. I'm trying my luck with the hot wire, watch this space...

Have you tried at 1 bar? ):

zomgwtfbbq wrote:Have you tried at 1 bar? ):

1 bar, 2 bar, 3 bar, 4 bar, 5 bar, no go

I tried with the hot wire, it was incandescent instantly (I could see it glow red through the araldite!) but still no ignition. I must be having mix/pressure issues, I think this really is too small to be practical...

What is the volume of this new cartridge you made?

Just 1.7 cm³...

Just 1.7 cm3

wow mine was a 85cc.

I guess the trick with these would be to have a premixed tank that you charge your cartridges from. Like a HPA tank, but filled with a 10x mix rather than 3000psi of air. that way all you would have to do is press the schrader up to a tire fill head, and it would be charged.

The other option would be to use something with a wider combustibility range, like hydrogen.

Lentamentalisk wrote:The other option would be to use something with a wider combustibility range, like hydrogen.

... or just stop trying to make everything so friggin' tiny!

I just now realized the size difference between our prototypes ( Brass is 7.62X54R) I could probably shoot your hybrid cartridge out of my hybrid cartridge.

irisher wrote:I could probably shoot your hybrid cartridge out of my hybrid cartridge.

Definitely You could also do more damage just by dropping that thing on the target

Together we could create a two-stage hybrid for some crazy range

Have you tried in HGDT using the mix calculator, and reading the chamber post fuel injection pressure? This is how i load mine. It's much more reliable than using the meter separately.

CpTn_lAw wrote:Have you tried in HGDT using the mix calculator, and reading the chamber post fuel injection pressure? This is how i load mine. It's much more reliable than using the meter separately.

I figured 0.4mL for a 5x mix, about right n'est pas?

Together we could create a two-stage hybrid for some crazy range