SpudFiles

ok imm asking that would this kind of combustion cannon work. It doesnt have a chamber really cause the barrel is the chamber at the same time and vice versa look the pic

if ill build this i would prolly put the fuel from the muzzle and the ammo too.

It'll work, DR built a basketball launcher with the chamber and barrel being the same diameter. Put a good size dent in the dumpster at a local plumbing store. Beyond that I can't critique the abstract of chamber diameter versus barrel diameter. Interesting question though, be interesting to read others thoughts.

Like CS said, it'll work, and power will depend on the calibre. For a 1/2" barrel it'll be shite, but an 8" barrel will work really well.

I wouldn't use it under 2", fuel mixing gets harder below that, and chamber geometry means the flame front will take ages to traverse the chamber.

They work great as mortars, don't have the power for direct fire that most cb guns have. i'd recomend using three stun gun spark gaps spaced down the chamber so you light all your fuel at once instead of lighting the back and forcing alot out the barrel. it looks cool but it's a waste. For the most bang use an arduino as a trigger for the three starting front,back,middle about .01 seconds apart if using propane.

is it a must for the barrel/chamber to be very thick diameter

Zeus wrote:I wouldn't use it under 2", fuel mixing gets harder below that, and chamber geometry means the flame front will take ages to traverse the chamber.

There are fans built that are small enough to fit in there. And a couple screw heads or whatever protruding to cause turbulence will fix the flame propagation problem.

Mr.Stark wrote: front,back,middle about .01 seconds apart if using propane.

If using multiple ignition points, there's no reason not to fire all at once. I mean, if the whole point of multiple ignition is to speed things up, why would you want to turn around and slow things down again?

well this what ill say will be a bit derailed, but any instructions to build a pneumatic one with a single barrel maybe i dont build a combustion one, i hate the hassling with ignitors and fuel mixing

I like to use fluid dynamics software and if timed right it makes a complete combustion so fuel is compressed to the rear instead of losing compression from the volume change as ammo gradually accelerates and can reduce felt recoil by as much as 60%.

A basketball launcher, Jesus Christ.

Anyway, of course it will work. The exhaust gasses have to go somewhere, so it will take the path of least resistance and shove the potato the hell out of the barrel.

iloveairguns wrote:well this what ill say will be a bit derailed, but any instructions to build a pneumatic one with a single barrel maybe i dont build a combustion one, i hate the hassling with ignitors and fuel mixing

http://www.spudfiles.com/forums/valvele ... t8912.html

Use the search function for more details. JSR was interested in the idea a while ago.