boytonstu,

I sent you an email (not a PM- an actual email) about your invention. - Hope it helps.

There is no way that I'd trust that (Dixon) type of quick-disconnect fitting at 40bar, let alone 70 bar.

I am converting my NERF Vulcan into a BBMG. It's powered by CO2 and uses a compressor blowgun. It is not a vortex gun, it's just straight fed. I need help coming up with a hopper or feeding mechanism of some sort. I've thought of many ideas, but so far, non of them will work. Any suggestions?

Ooh ...

Any time you "harden" your ammo you make it more destructive. Anything solid. Thing like oranges, lemons with a pulp texture tend to mush. I've all ways wanted to freeze a egg and try it but I have a 1" bore ... :wink:

jrrdw - Have you ever tried a piece of #8 rebar? Nominal Diameter is supposed ...

1/4" Steel Brake line has an inside diameter of 3/16" (0.188)

1/4" Galvanized or "Black Iron" pipe has an I.D. of 0.364"

1/4" Copper "K" pipe: 0.305"

1/4" Copper "L" pipe" 0.315"

From what I see playing around with HGDT's range calculator, it seems unlikely that such a projectile is going to reach 500 yard range without assistance from wind or topography. Even with a fairly optimistic drag coefficient of 0.5, it doesn't look like a potato is heavy enough. It might be ...

Cut a full-grown pumpkin open and you'll find the center mostly hollow, so your comparison of throwing a rock as opposed to throwing a handful of sand, is not even close to comparing a spud next to a pumpkin.

I had mentioned freezing a pre-cut potato slug, but only to help prevent the potato from ...

As previously stated on this forum it's a shame sometimes that people put so much effort into their launchers while neglecting the projectile itself - ie if its performance you seek, it's no use building the best combustion ever if you still insist on firing potatos...

I also agree that people ...

First attempt (ever) at making a spreadsheet... Not too easy, when you don't have the slightest clue as to what you're doing!

Geez!... I barely figured out how to save something as a .zip file, just so that it could be added as an attachment to this post... Sucks, not to be computer-savvy.

The ...

jackssmirkingrevenge wrote:*cough*

Uh... your link to a 60ml syringe will only yield a 2.8% fuel mixture -

critter wrote:If I do a psi gauge and pipe what psi would I use

2psi in 11-3/4" of 2" SCH40 PVC pipe.

Your C:B ratio is 1.36:1
A larger ratio such as this will produce a loud report, but a larger report doesn't equate to a more powerful cannon. Your chamber volume is actually large enough to support a 7-1/2' long barrel of 1-1/2" pipe.

Spray-n-pray is not the ideal method for fueling a launcher ...

With 2BAR of compressed air and (about) 2psi of propane in the chamber, his mix was only 4.535% ...(Again: "about")

The only thing to really worry about, is that the peak combustion pressure of successfully igniting a mixture as he's described, is slightly over 300psi.

... Well, actually ; I do ...

The "rectangle" ; Did you want to create a groove in it, similar to this?

Thanks for the reply

No, the sprinkler valve is attached correctly (i.e., arrow is pointed towards the barrel). The gun fires fine, but the air leaks out of the pilot exhaust valve stem, so you need to fire it before the air all leaks out.

<b>I'm not sure what you mean by # 2... how would this ...