VERY Simple Combustion

[mark.f]

This is a gun I made today for around 20 bucks. Simple, easy to use, and quite powerful given it's size. Chamber is 18" of 2" SCH-40, and the barrel is 48" of 1" SCH-40. Over under design, breech-loading barrel, ignition handle, and piezoelectric ignition.

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Last, I know this looks kind of "Blue-Flameish", but it's actually based off my first combustion, with the addition of the handle. It suprised the hell out of me when I finished, that it looked exactly like a Blue Flame cannon.

Butane works great, but the loudest shot so far has been with the solvent cement fumes.

[Insomniac]

Cool! What colour are you going to paint it? I really like the look of over under combustions. You should put a muzzle break on the end 'just for looks' Great cannon.

[mark.f]

Ehhh... I'm not gonna paint it. Defeats the purpose of me building it as a simple cannon to play around with.

I've also figured out something very cool. Instead of a chamber fan or anything fancy to mix the fuel, throw in a few pennies, (about $0.20 worth), and shake that around after spraying in fuel. Makes the thing fire like pie every time with a nice, loud report.

[Bluetooth]

Is your avatar from a Disney movie? Do the pennies leave the barrel every time?

[mark.f]

Yes my avatar is from Bambi. It's sort of an inside joke between me and somebody.

No, the pennies don't leave the barrel. They stay in the bottom of the chamber. They can't get past the elbows. Don't know how they'd work in an inline, but I expect they won't leave the barrel either.

Stuff in the chamber itself don't fly out as you may think. I used alligator clips on my cousin's gun for the fan, one of which is connected rather loosely to the electrodes. They don't budge after a bunch of shots, and that one is propped on there pretty precariously.

[Scope]

They most likely wouldnt unless they where facing upright in the barrel when u fired because hte pressure would just go around them

[PVC Arsenal 17]

Nice breech idea. That's the concept I'm Building by omega around. The barrel is sliding throught the guides right?

[mark.f]

Yup. They stick a little, though. If you wanted to counter that, (it's not enough to bug me significantly), on your gun, line the inside of the guides with some felt and make them a little looser. Also, I'd suggest making them out of steel so the clamps don't warp them around the pipe. My clamps aren't tightened that much, or they'd do it.

[Bluetooth]

I have to try that penny thing on my new camera flash ignited, butane fueled, basic combustion. It should be done on Saturday . I was just working on the ignition a couple minutes ago, drilling all the holes for the electrode wires.

[mark.f]

Sounds good. Just don't let the pennies short out your spark!

How are you going to be using butane? I just slapped the nozzle off a deodorant can onto the stem of a Ronson refill cylinder. 2 seconds works perfect in this launcher.

[Bluetooth]

I was thinking butane lighter.

[PVC Arsenal 17]

I'm likin the small combustions lately. I think I might to get back into them. I want to build one with a 1/2" CPVC barrel for marbles.

[mark.f]

Yeah... the projectile is everything.

The reason I built this is because the first one, (built a while ago last year, and now gone), shot darts made of a hot glue stick wrapped at the top with duct tape pretty well. I made this just because I had an itch to shoot these things again. The first version of this gun, (old one), shot them across the yard, (about 45-50 yards). This version will shoot them across the back field adjacent to my house to the treeline, (about 80-100 yards).

It's the pennies. I know. They're contributing to the molar count.

[Bluetooth]

Hey, do you think airsoft BBs would work instead of pennies or do they need flat surfaces to act as fans?

[PVC Arsenal 17]

Probably, but after a while the chemicals in the propellant might break them down. They may stick to the sides too if it gets gummed up. Some steel .177 bb's would do just fine too.

*woohoo 500 posts!!*