SpudFiles

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!!)

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.

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.

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?

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

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?

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.