Well I finally managed to salvage an old cannon I made in high school about 8 years ago. I hooked it up to an air supply and it actually works still.
It is a bit unique as it uses a pneumatic ram actuated 65mm (2 1/2") ball valve, the ram is fired via a solenoid valve.It also has a pneumatic recoil absorbtion system, which would reduce the muzzle energy, but it stops the thing from destroying itself. The cannon is mounted on a 2 wheel wooden carriage.
Just a few specs:
Bore: 80mm (3")
Barrel Length: 1450mm (57")
Chamber Diameter: 80mm (3")
Chamber Length: 1350mm (53")
Elevation Arc: +45 to -5 degrees
Recoil absorbtion travel: 250mm (10") with adjustable rebound
working pressure: 4 - 9bar
Max rated pressure: 12bar
Muzzle energy: not yet tested (coming soon
)Here are some Photos.
P.S. I know it is very ghetto and dodgy, but hey I made it when I was in high school
I will upload some firing and damage videos in the next day or so, after I have time to break some stuff
UPDATED, Here is a Video of it firing:
[youtube][/youtube]
I am going to remake the valve bellcrank and pneumatic ram to make it a little less errm........Ghetto
also need to fix some leaks 
SubsonicSpud
