Air cannon



  • This is the cannon. 2" ball valve welded into a 7 gallon air tank.
    2 1/2" electric conduit barrel. We have shot everything from tennis balls, to water balloons, to rocks, to walnuts, to plain water.

    Charging the cannon

    Firing the cannon straight up with a tennis ball.



  • Artillery! My true love

    Do the waterballons stay intact till they get downrange? I have a annual water fight with some younger cousins/nephews and I'm looking for a way to extend my range.



  • If you load a plain water ballon into the barrel it will burst when fired with anything over 17 psi. It will shoot about 50 yards.

    If you put about 12" of water in the barrel and then the water ballon it can handle up to 70 psi without bursting the ballon. At 70 psi I can see broken ribs at 40 yards. I haven't tried for max distance yet at 70 psi...but would estimate it to be in the 120 yard range.



  • That thing brings a smile to my memories of the past. I made a few acetylene powered cannons in my misguided youth. They were awfully loud. Pretty dangerous too, I'd suspect.
    Your Compressed air cannon hints at what the acetylene cannon would sound like with a good muffler attached (or I would wish to think so anyway).



  • Some friends of mine built an air cannon in school that would shoot a can of soup 4-500 yards. They are impressive.


  • Banned

    Almost embarrassed to share this story, but if it prevents someone from pushing materials too far, it's worth it.

    I had a potato gun that used hair spray and could shoot potatoes100-200 yards. 4" chamber about 2-3 feet long, and a 5' long 2" barrel. It was really fun launching them 1/4 mile with the same potato gun... but it didn't last long. The oxy+acetylene mix to make them go that far was a dumb 16 year old idea that only worked a couple of times. I normally don't share my dumb teenager stories, but if it starts to get boring, don't "up the ante" as I did. When it's real quiet, my ears are still ringing.



  • @brittel

    I can see the oxy/acetylene mix being a little more potent than hairspray. I bet it was loud! I never have built a fuel fed cannon as the air has always had more than enough power to satisfy me.

    I have been playing around with air cannon's like this for some time now. This version is about 5-6 years old and has worked very reliably so far. The early editions...it is a wonder someone didn't get hurt.

    The first one I built had a pvc air chamber instead of the steel tank. It also was 4" pipe about 2 ft long...and I would air it up to 80 psi. PVC is rated to something like 300 psi so 80 shouldn't be a problem, right? Incorrect!!! PVC can easily handle 80 psi unless it has a "shock" factor to it. When it is aired up to 80 and then immediately dumped it will fall to pieces after about 25 firings. After having it rupture and rebuilding it about 3 times I finally figured out that PVC was not going to work for a chamber.

    right now the only pvc I have in the thing is in the barrel after the valve. It does see some back pressure when firing the gun...but it is only instantaneous and immediately bleeds off to zero as it is fired. I have probably 500 firings on this setup including some pretty heavy things and have not had any trouble out of it. That is not to say I won't ever have trouble...but it works for now. I shoot it at 100 psi max. The tank is rated at a working pressure of 125 psi...so it can handle 100 just fine and I don't intend to push that limit. Without a longer barrel more air will not really gain me much velocity anyway.



  • Time to start working on a pumpkin air cannon @dddoo7. Those things are impressive.



  • @brittel said:

    Almost embarrassed to share this story, but if it prevents someone from pushing materials too far, it's worth it.

    I had a potato gun that used hair spray and could shoot potatoes100-200 yards. 4" chamber about 2-3 feet long, and a 5' long 2" barrel. It was really fun launching them 1/4 mile with the same potato gun... but it didn't last long. The oxy+acetylene mix to make them go that far was a dumb 16 year old idea that only worked a couple of times. I normally don't share my dumb teenager stories, but if it starts to get boring, don't "up the ante" as I did. When it's real quiet, my ears are still ringing.

    I sure can relate, got a good laugh at this! They sure were loud, got me in deep doodoo on the LAST firing....enough said..



  • @norcal_in_az said:

    Time to start working on a pumpkin air cannon @dddoo7. Those things are impressive.

    I would love to build a pumpkin cannon. I imagine one would need about $100k to be competitive though.