Jimmy the formula above does give 4%....and the equation you used
"2.512/(62.8+2.512) = 3.85% " is wrong i think, why did you add the 2.512 to 62.8 ?

Man that is looking really good! Good Job!
Definitely keep us posted when you build more

Thanks for the info jimmy...ill be getting one when i get paid next and when i have time...prob in the next couple weeks...Ill be sure to take pictures while Im taking it apart and rebuilding it and if it does work ill be sure to make a "How To"!

I would go but ill be camping that week, and i work full time. That and my parents threw out my spud guns while i was at college cause i thought i had "out grown" that hobby. Haha....Once a spudder always a spudder! Still have to build the propane one i have been planning!...But you guys have fun an...

Oh nice....any good places to launch around there....all i have here are small parks
and cops dont really like that

Ventura(ish) area, California

Finally found one here.... Here

Which do you think would be better?

Im in the process of building/planning out a propane powered spud gun and wanted a repeating spark. Stun guns are an option but i have seen some guns with electric bbq ignitors/starters and I was wondering where you get them? I have looked all over the internet/forums and have come up with nothing. ...

Well, just a little input, but if the two guns are the same size, you could make one propane meter for it, with a ball valve going to each gun. Noname has the right idea with the propane system. You might be able to set it up like this: See picture The slanted lines in the middle indicate male/fema...

nsane-spuds wrote:it's a electric BBQ igniter with red electrical tape

Where did you get it?

A stun gun is not really necessary for a combustion gun, though it's the "holy grail" of ignition sources. In fact, they're kind of a pain in the ass to work with, because you have to use thick-gauge, insulated wire for everything, keep them from touching at all, etc.... Personally, for a normal co...

I am still an intern in a sheet metal fabrication plant. I work in both sales and engineering right now. 3 semesters to go! I don't do much with animation, but just about anything can be drawn as a solid part. I don't know if you checked out that link, but Bliss is a VERY helpful resource with thes...

Hi, I have built a few combustion Spud Guns in the past (all hairspray) and wanted to experience the power of Propane. I have been reading up, a lot, on how to build one and how the metering system works, and I had some time so i drew up a sort of schematic and wanted to run the numbers/schematic th...

Great gun! very aesthetically pleasing. How does it look when you fire it at night? It doesn't look like you have an internal chamber fan, which could help power, and a longer barrel would give it more oomph, but I'm not sure you can change that one. An inner chamber fan has i think been proven to i...

Well for me, like VH, it all started with Backyard Ballistics. I made my first one but could only shoot it in around my house, which is in a surburbia, so i have never actually used a potato as a projectile. The first cannon i made i used ping pong balls that were wrapped in tape, and then did prett...