SpudFiles

this is just an idea i had, i want a smaller combustion gun but not quite a mini, just something moore compact. the barrel is recessed in the chamber, they aren't quite to scale. just wondering what you thought about it.

so you want to make a coaxil combustion cannon, why no just make it pnuematic? but if you do stick with layout i dont know how well it will work becuase of the bends the pressure has to take to push the potato. ify ou want to make it compack gun just make it so you can screw on and off the barrel. that way while your moving it wont be that big and you wont scarifce any performance.

i had the same idear but i thought it might have a bit of a small chamber

A 6 inch chamber would help performance with this design. Because the barrel is taking up alot of space.

yeah killa that was sort of what i was worried about, not having enough curculation of fuel in the chamber, a 6 inch chamber would probably work

im thinking with the small areas around the barrel you might cause problems of fuel mixing throughout the chamber lowering the overall efficiency of the gun..just a thought

make it propan and have it go in through the front coupling so then it would move bakwards, or to save space just build an over under

Original hope it works if it doesnt then we will all laugh together.

it would be a lot better if the spark was at the front of the gun ... kinda like how in a reg combustion its supposed to be in the back

Yea i say spark in the front fan in the back.. you should run duel ignition on opposites of the pipe so it doesnt have to curl around to ignite.

I drew up one of these a couple of years ago but never built it, very similar to what you have here. My personal issue with it was the seal between barrel and the front end cap and how well the drilled cap will weld to the barrel. I also was concerned with supporting the back end of the barrel but I see you've done that with screws. You could even make those screws double as ignition points. I think it's a great idea and your schematic looks solid. Go for it dude.

Here's my dusted off and cleaned up since reading some of the other comments on this type of gun. One thing is for sure this would be one heavy mutha. I think what would make this work is the modified flush mount reducer inside the chamber. I was thinking of modding it so that the entire thing fit into the chamber, weld it in place and that would create the more efficient flame front. I didn't illustrate the ignitor but that can go anywhere. Maybe I'll build this one next.

thats pretty kool I was thinking about making one but never got around to it

what would be the best chamber and barrle sizes