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Posted: Sat Apr 17, 2010 10:48 am
by CpTn_lAw
Yes, you were right after all, But anything over 0.3mm or 8x won't ignite. I haven't fired it since last week.

Posted: Sat Apr 17, 2010 10:55 am
by jackssmirkingrevenge
In that context, this idea might work if slightly modified like so:

Posted: Sat Apr 17, 2010 12:52 pm
by POLAND_SPUD
don't you think that this would be better?

http://www.spudfiles.com/forums/hybrid- ... 20675.html

Posted: Sat Apr 17, 2010 1:18 pm
by CpTn_lAw
JSR: I still think the stungun is the best idea, it has the advantage of agitating the molecules in the case it doesn't ignite them. So, with the relatively high frequency of sparks, if the mix doesn't burn at first, it burns quickly after. I think your design is really good. REALLY.

Posted: Sat Apr 17, 2010 1:35 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:don't you think that this would be better?
Interesting idea for an auto, but too complex for a cartridge based mechanism.

I made another cartridge prototype in the meantime based on the diagram posted above, with the spark gap as small as I could manage without the wire actually touching the cartridge body, we'll see how it works with a piezo. Sadly stunguns are illegal in Epoxyland so I have no easy way of upgrading my ignition source.

Posted: Sat Apr 17, 2010 1:51 pm
by CpTn_lAw
Why don't you build one? On the French forum, they suggested that a Ruhmkorff coil can produce enough "juice" to spark in a hybrid. You just need a iron core, copper wire (two different sizes) and a lot of time. I don't know, maybe I could try... something like a 1:10,000 step-up ratio might be good lol

Posted: Sat Apr 17, 2010 3:33 pm
by POLAND_SPUD
Interesting idea for an auto, but too complex for a cartridge based mechanism
well the idea behind it is not to have to use cartirdges in the first place... in fact your design inspired this though I don't know when I will be able to finish this

Posted: Sat Apr 17, 2010 3:49 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:well the idea behind it is not to have to use cartirdges in the first place...
But the thing is that I want to have a working self-loading cartridge system, not a semi/auto hybrid. The advantages of using hybrid cartridges over pneumatics (assuming a friction breech is used instead of a burst disk) are several:

- lighter, simpler cartridge with more power per cubic capacity with a comparable HPA design

- no need for a strong bolt spring to hammer a pilot valve open, making the possibility of a self-ejecting cartridge more realistic

I seem to be getting good internal spark with my latest prototype, I'll give it a go tomorrow. I'm not happy with the centering of the breech, so I hope it works but blows up :D

Posted: Sat Apr 17, 2010 9:48 pm
by zomgwtfbbq
jackssmirkingrevenge wrote:
POLAND_SPUD wrote:well the idea behind it is not to have to use cartirdges in the first place...
But the thing is that I want to have a working self-loading cartridge system, not a semi/auto hybrid. The advantages of using hybrid cartridges over pneumatics (assuming a friction breech is used instead of a burst disk) are several:

- lighter, simpler cartridge with more power per cubic capacity with a comparable HPA design

- no need for a strong bolt spring to hammer a pilot valve open, making the possibility of a self-ejecting cartridge more realistic

I seem to be getting good internal spark with my latest prototype, I'll give it a go tomorrow. I'm not happy with the centering of the breech, so I hope it works but blows up :D
Sounds good. Can't wait 8)

Posted: Sun Apr 18, 2010 2:04 am
by jackssmirkingrevenge
zomgwtfbbq wrote:Sounds good. Can't wait 8)
Likewise, it'll be a few hours before I test it as I'm at bloody work :x effin' clobetasol-17-propionate :roll:

Posted: Sun Apr 18, 2010 5:13 am
by CpTn_lAw
Why are you talking about corticosteroids?? XD

Back on topic: be sure to post anything about your testing! I can't wait to read about it!

Posted: Sun Apr 18, 2010 5:22 am
by jackssmirkingrevenge
CpTn_lAw wrote:Why are you talking about corticosteroids?? XD
Because managing their quality how I finance my spudgunning :roll:

Updated theoriginal thread to stop hijacking this one, I will post test results hopefully by this evening :)

Posted: Mon Apr 19, 2010 8:32 am
by CpTn_lAw
Ok, so here was the setup about 6 minutes ago....
It is a warm sunny day in France, and in my house, after carefully drinking a dozen soda cans for the last two and a half weeks, I thought to myself :
-"what a beautiful day to make a penetration test!"

So here i was, prepin' the shooting range (aka the house). I put 10 soda cans on the ground, like that "under ->over -> under ->over etc..." and a tin can, stuffed with high density foam.
8x shot, 45 bars burst disc, 8mm for 1meter barrel
Projectile: 8mm ball bearing 2 grams, with a little teflon tape(one half wrap)to give perfect seal. HGDT gives 434 m/s .

The ball bearing went through every can, then stopped 6cm into the foam.
And here is the HD carnage. :D Hope you like it ;)



[youtube][/youtube]

Posted: Mon Apr 19, 2010 3:01 pm
by CpTn_lAw
8x, 16mm plastic cap, less than a gram, HGDT gives 680 m/s

[youtube][/youtube]

Posted: Mon Apr 19, 2010 3:12 pm
by jackssmirkingrevenge
Fork in hell! Wish I had similar tales of success :?