Hybrid preview

[CpTn_lAw]

Ok everyone hello!
I've been wanting to do this for a long time now, almost came to finish it! A 5x, handheld on rifle stock, on-board propane hybrid!!!! woooohooooo
This is only a preview, as I need to buy an ignition source! (and later, a more ergonomic way to hold the canister.
Here is some pictures, it's almost done, Just really need a reliable ignition!! Can't wait! I'll post the detailed specs in the showcase, as well as a video containing high-speed footage of hybrid destruction, muzzle flame etc etc...
Build time : well, to this point 1h30. If we count all the messages i've wrote saying i'd do it...well...2 years ?






Hey JSR, no feet XD (What an effort it was to resist temptation!!)

[ramses]

Nice. The meter pipe looks rather small, but you can always fill it multiple times. You are "old" enough to know about metering so I'll leave it at that. I have to say that I favor volumetric metering now that I realized manometric is such a PITA.

[CpTn_lAw]

yeah well, the eter is small but so is the chamber, so I figured 4% propane per 'X' gives me (in my case) 7,84 cubic centimeters of gas. (196 cc chamber volume) , My meter is 8mm wide (inside) for 12 cm long = 6cc .
So as the gas i'm using now has a pressure of 2 bars,I need 4 meter volume==> I need two injections at 2 bars to give me a 4X mix. (plus 3 atm of air added)

I don't see it difficult, i'll make small marker dots for each mix, and another dot for the number of injection at desired pressure to attain correct mixing.

[psycix]

5x on a stock. Me likey!
Just hold 'r tight, I wonder what kind of recoil you'll have to handle.

Whats the bore diameter?

[CpTn_lAw]

I have several diameters (for barrels XD ) , a .40 cal , a 16mm , a 20 mm, and a 24mm . The current holding system ( read zip ties) is just...well, to set it tight before i shoot it. I will use steel clamps to secure it definitely.
I don't know either was sort of recoil my shoulder will have to take... hope it's beasty

[psycix]

I don't know either was sort of recoil my shoulder will have to take...

Are you shooting marshmallows, steel ball bearings or lead slugs?

[CpTn_lAw]

Ok I ran some numbers through HGDT !! I must say i'm quite surprised about the power difference between each number of mix.
HGDT predicts that with a disc failure at 30 bars, a 5X shot of a 1.58 cm marble will accelerate it to 391 m/s ...that's bloody fast! It will developp 359 joules.
Now if I shoot a 12 grams lead bullet, 260 m/s, in 7ms (projectile left barrel) the stock will take 1m/s against my shoulder. That is about 1.5 joules...not much! That's about as powerfull as a .44 black powder revolver. (with standard load! don't give me the "remington walker at 3 grams load?")

Voila...i think next stop is ignition and then testing! i'll keep you posted.




EDIT: Tested The hybrid!!!!!! I'll post videos as soon as i can! In a new shocase thread. The 350kV stungun provides a sharp noisy spark at high frequency, and ignites everytime, even with little mixing errors. The cannon makes a deep and very low pitched "THUMP" sound.