A simple air cannon

Remember how I said I might build an air cannon this weekend? Well I did, for less than $30 AU. This design is probably one of the cheapest, simplest and most reliable potato cannon designs you could possibly build. All parts are rated to at least 12 bar (174psi), which is a ton more power than needed for a bit of fun.

You should have seen the looks I got when I pulled this out of the garage...

This thing is over 2 metres long, has a 30.25mm I.D barrel, 50mm I.D pressure chamber, simple ball valve operation and a schrader valve as the fill valve (car tyre valve). So far, I've done test shots using potato ammo at 50, 60 and 75psi and the results so far have been AWESOME. This cannon at 75psi is as powerful as my old propane cannon of the same caliber. I'm pretty interested to see the results of taking it up to 150psi, but I need a decent compressor to test that. I may need to add barrel rifling to stop the potatoes from going out of control too...

While at the moment it remains in an unpainted, rather crude look with bootlace to attach the shoulder strap, this cannon can easily be changed to an under/over layout with a threaded barrel for breach loading, so in the near future I might either upgrade this, or build bigger and perhaps go to a 45mm I.D barrel with a 65mm I.D chamber. Even then, I doubt that kind of setup would take more than $40 and 30 minutes work. So, I guess now you know that I don't just screw around with Nerf blasters, I also try to put vegetables in to low orbits!