SpudFiles

Hey guys hows it going.

I've made 6 or so cannons so I know a little about what I've worked with but I've never made a Coaxial. I've got the raw materials. I have a:

1m long 15mm barrel.
1m long 32mm chamber.
25mm modded sprinker valve.
Heavily modded blowgun.
Hot glue piston.

I just don't know what the power is gonna be like or what to expect....

If anyone can gimme' some info, it'll be greatly appreciated.

Thanks alot,

Mitch.

With those specs, performance can best be described as "fearsome" - keep the space between the back end of the piston and the inside of the chamber to 4mm (a piston only needs to move back 1/4th of the barrel diameter for maximum flow, anything more than that is simply wasted space) for maximum efficiency and you'll have a winner. If you manage to do the above I would say that the blowgun alone would be sufficient to pilot the valve - hell, even a schrader would do. I used the latter succesfully to pilot the 26mm piston in this project - the specs are vaguely similar so you have an indication of what performance will be like.

Thank you so much for that Jack. Thats unreal. I'm only gonna use about 120psi though, I hope it should be enough. What psi are you using in yours? I'm drooling over your cannon's vids now haha.

All the best mate,

Mitcho.

All those vids were done at 110 psi, that's the best my compressor can manage. Glad to have been of help/inspiration

Ah wow I should be able to expect some good results then haha. I've never seen a Coaxial like yours. It's like.....a T Valve crossed with a Coax It must have been a b1tch to get everything to seal up well. How did ya go about that?

Mitcho.

Lots of epoxy, patience, and hardcore anglo-saxon blasphemy. It would have been easier to make it a co-axial but I wanted to maximise chamber volume.

Yeah thats what I was worried about. I'm thinking that I just don't have enough air. I'd love to think my new cannon will be "fearsome" but I just have a bad feeling.... I'll just have to wait and see. So what other cannons have ya made?

Mitcho.

Mitchza89 wrote:Yeah thats what I was worried about. I'm thinking that I just don't have enough air.

Don't worry, punched in some numbers and since your chamber is longer, you actually have the same chamber volume with a coaxial design, slightly bigger actually

Some other designs of mine:

http://www.spudfiles.com/forums/vortex- ... -t166.html

http://www.spudfiles.com/forums/the-bea ... t7457.html

http://www.spudfiles.com/forums/cartrid ... t7176.html

http://www.spudfiles.com/forums/6mm-cro ... t7946.html

http://www.spudfiles.com/forums/pneumat ... t7858.html

http://www.spudfiles.com/forums/files/hvbb_681.jpg

http://www.spudfiles.com/forums/files/t ... ia_157.jpg

jackssmirkingrevenge since you seem to know alot about co-axials, if i had a 3 inch diameter chamber, what size should the barrel be?i want the barrel to be just a bit longer than the chamber like 3 inches or so ,sorry Mitchza89 to be taking over your topic ,but i dont want to start a new one just to ask this question.

I'd say it can afford to be a 2 inch barrel, though 1.5 inches would probably be optimal.

ok, thanks, 1.5 it is

Haha no worries at all super spuder. So by the sounds of it, you need roughly a 2:1 ratio with the chamber n barrel. I was gonna go 25mm for the chamber but I just thought it would be a bit too small. so I went with for the 32mm. I reckon this will be my best cannon to date. I'm gonna put a decent stock of the back of the Sprinker Valve, paint it totally black and maybe make a Bi-pod but I'll see how I go with my money left over.

By the way Jack, those are some amazing cannons/air soft guns you have there. I'm amazed! haha.

Have either of you guys got any projects ahead?

Mitcho.

About how long would you recomend making coaxials such as the 1.5" barell and 3" chamber?

P.S. By the way, Jackssmirkingrevenge, nice work! Those guns are amazing!