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Posted: Sat Aug 02, 2008 8:02 pm
by rp181
not much a small step, who builds a 200x hybrid as there hybrid. If anyone else mentioned it.....
nice cannon, do you have ways to mesure the peak pressure in the chamber?

Posted: Sat Aug 02, 2008 8:39 pm
by Sticky_Tape
WTF I seriously have no place on this forum no not seriously but :shock: WTF
Larda you little ultra owner.

Posted: Sun Aug 03, 2008 3:10 am
by Ragnarok
I'm going to have to admit to muppetry. I made the error of doing my mix calculations with gauge pressures, not absolute pressures. D'oh!

What that means, in theory is that this can be beaten with a standard propane air mix - hybrid mixes of maybe... 225x or so, should be possible at room temperature.

However, that's still no huge leap... cos' I figured out how to make a 320x mix possible without faffing around with high pressure fuels like hydrogen, any bulking out gases or higher temperatures, just easily available fuels - and air of course. :D

The trick to dealing with propane liquefying in a hybrid, is to after you've hit the 225x limit... is to start using butane as your fuel.
A mix with 2.93% propane and 0.97% butane added (2.82% and 0.94% respectively by total volume) could be compressed to 320x or so without any of the fuels becoming liquid.
The potential power would be over 40% greater than what could be managed with propane mixes alone, and 60% greater than what Larda has achieved here.
Supposing Larda could use such a mix in this cannon, I think a muzzle energy of about 20,000 ft-lbs might even be achievable. Given that's starting to approach the sort of power of the vast 14.5x114mm round... you get an idea of what mix numbers like 320x mean.

Posted: Sun Aug 03, 2008 4:41 am
by rna_duelers
If you had of mentioned going to 100x mix let alone 40x mix a few years ago you would of been yelled at for trying it with the risks of DDT,but look at this....I'm Amazed,literally in shock.

I love it.

Posted: Sun Aug 03, 2008 7:12 am
by psycix
pizlo wrote:As for the gun...
I think many members were acting a lot like this
<YOUTUBE>
That video would rock even more if the box was found to be empty by the kid.

But yes, I would react like that if there was a 200x mix hybrid in a box under my Christmas tree.


BTW, its not "that" hard to top off this gun. Instead of building a gun with an higher mix, build another 200x mix gun, but then with double the volume.

Larda, I got a few questions:
-What did this project cost you?
-How much does this gun weigh?
-Could you try to give an indication how loud the bang is?
-Could we get a pic of your burst disks?
-What did you use as barrel?

Posted: Sun Aug 03, 2008 9:29 am
by Mr.Sandman
Larda wrote:Thanks for all the comments, not that bad for my first hybrid, i think. :D
not bad this thing is f@$king insane man. everything is high quality the ammo, cannon and pictures. i mean is anything else not been done? :shock:

Posted: Sun Aug 03, 2008 10:18 am
by starman
psycix wrote:Larda, I got a few questions:
-Could we get a pic of your burst disks?
Yes please. Could you detail your burst disk scenario? You mentioned a brass one briefly. What are its dimensions? I assume you machine them as well. Are you simply tightening it down by screwing in the barrel?

Posted: Sun Aug 03, 2008 10:28 am
by SpudFarm
well i have some pics of his burst disks and know how they are tigthened down, but i don't know if he wants to show it off himself

i think his disks is layered THIN brass plate like he used on my hybrid on a test shot, they are like 0.025mm thick each

Posted: Mon Aug 04, 2008 11:29 am
by willarddaniels
I am truly amazed and find myself with others in a jealous frenzy. I wish to express my condolences to all inanimate objects that stand in the way of this monstrous work of art. Great work, Larda.

Posted: Mon Aug 04, 2008 11:37 am
by GalFisk
Jävlar, Larda! That's one awesome cannon. More damage pics please (would also be interesting to see what sort of damage the sheer pressure from a dry firing can do).
About firing >200x mixes, I suspect any liquid propane would diesel when the gas is ignites, so as long as you don't go below the LEL for propane/air (which may not be the same under these pressures as STP) all of it will ignite.
To get beyond the LEL, have an ignition chamber of 200x which induces dieseling in the main chamber.
Charging of the main chamber >200x could be done by injection of liquid propane, or using 2nd gen fueling methods.

Posted: Mon Aug 04, 2008 12:40 pm
by bob-a-lu
HOLY $H!T

Posted: Mon Aug 04, 2008 1:11 pm
by SpudFarm
Galfisk is on it again :D

Posted: Mon Aug 04, 2008 1:42 pm
by brogdenlaxmiddie
Just had an idea... Would it be possible to take say, a fridge compressor, and attach a large propane tank to the inlet and then have the outlet go into the gun, creating really high-pressured propane? That may help by making the gun get Higher mixes. The only problem, would the compressor by anychance ignite the propane while its being compressed?

Posted: Mon Aug 04, 2008 2:00 pm
by SpudFarm
it wont work since it will turn into liquid in the compressor..

a high pressure waterpump can pump liguid propane in there but it will be hard to messure

Posted: Mon Aug 04, 2008 2:07 pm
by ramses
@BROGDENLAXMIDDIE- that would not be possible because the propane would liquify, just like it is in the bottle. It shouldn't ignite if the pump was purged with an inert or flammable gas first.

nice, larda. The Taylor KO factor for the plastic slug is ~87. compare that to the:

.22 -1.35
ak47- 12
m16 -6
9mm -7.2
.45 -32
.50 bmg/m82 -165
m134 minigun- 17

the low mass of the slug is keeping you down... do you still have the tungsten carbide from the ETG?