hybrid cartridge protoype without burst disk

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
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jackssmirkingrevenge
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Mon Apr 19, 2010 2:15 am

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 :D 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.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Apr 19, 2010 4:04 am

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 (:
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jackssmirkingrevenge
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Mon Apr 19, 2010 4:39 am

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 :roll: 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...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Apr 19, 2010 2:04 pm

Have you tried at 1 bar? ):
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jackssmirkingrevenge
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Mon Apr 19, 2010 3:13 pm

zomgwtfbbq wrote:Have you tried at 1 bar? ):
1 bar, 2 bar, 3 bar, 4 bar, 5 bar, no go :cry:

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...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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theBOOM
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Mon Apr 19, 2010 3:26 pm

What is the volume of this new cartridge you made?
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Mon Apr 19, 2010 3:55 pm

Just 1.7 cm<sup>3</sup>...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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irisher
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Mon Apr 19, 2010 3:59 pm

Just 1.7 cm3
wow mine was a 85cc.
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Lentamentalisk
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Mon Apr 19, 2010 4:59 pm

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.
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Mon Apr 19, 2010 5:05 pm

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! :roll:
hectmarr wrote:You have to make many weapons, because this field is long and short life
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irisher
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Mon Apr 19, 2010 5:11 pm

Image 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. :lol:
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Mon Apr 19, 2010 5:38 pm

irisher wrote:I could probably shoot your hybrid cartridge out of my hybrid cartridge. :lol:
Definitely :) You could also do more damage just by dropping that thing on the target :roll: :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
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irisher
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Mon Apr 19, 2010 5:41 pm

Together we could create a two-stage hybrid for some crazy range :lol:
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CpTn_lAw
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Mon Apr 19, 2010 6:17 pm

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.
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Mon Apr 19, 2010 11:43 pm

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
:D :D :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
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