The D.S. Pistol

[FeLeX]

You guys should most def check this out.
Maybe the plans can be modified and a barrel can be implemented in the design.
http://www.snowcrest.net/fox/logan/cost ... unbp1a.JPG
http://www.racprops.com/issue4/logansrun_dspistol/
http://www.racprops.com/issue4/logansru ... prints.jpg

[FeLeX]

Bumpitty Bump BUmp

[Hubb]

Essentially, the acetylene gas is ignited just as it leaves the barrel to shoot a flame, correct?

It does look, with modifications of course, that it would be a nifty little combustion pistol. Maybe even a nice hybrid of some sort. I don't know. When does your construction start?

[FeLeX]

Well Im building a cnc machine in my electronics class. I get to keep it. I was also going to build a lathe and then Ill try and build the original first. Later on maybe implement the barrel I was talking about.

[jimmy101]

Hmmm, pressurized acetylene gas, always fun for a few laughs.

Note that the drawings say to mill the acetylene generating chamber out of a solid piece of metal, "don't weld or braze end caps onto a piece of pipe".

With a small enough acetylene chamber the damage caused by the acetylene autoigniting would be small (relatively speaking).

[FeLeX]

Hmm so its only good for being a nice noise maker?

[jimmy101]

Hmm so its only good for being a nice noise maker?

Basically, yes.

Carbide cannons are generally only used as noise makers. Put something in the barrel and you have to design for the much higher pressures the gun will operate at.

At relatively modest pressures acetylene will go off by itself, with or without air present. For most gases this wouldn't be a problem since you can precisely control the pressure in the chamber. But with calcium carbide and water the amount of acetylene you generate (and the pressure) is difficult to control.

There is a reason why spudders don't use acetylene as a fuel.

If you want to use the basic design in a much more practical version just replace the carbide generator with a disposable butane lighter. Remove the sparker from the lighter and link the fill trigger to the lighter (basically exactly as described in the drawing). Replace the hot-wire ignitor with a piezo sparker, perhaps ripped from the same device the butane container came from, like one of those long handled BBQ lighters.

The only real advantage acetylene has over any other fuel is that is has an extremeley wide combustion range in air. IIRC 3%~80% (or so) gives a combustable mixture. (Hydrogen also has a very wide limit of combustability.) So, you get a "bang" with just about any fuel to air ratio.

[FeLeX]

Hmm. =/ Well I still think its a coll lil design.