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Big Bertha Air Cannon

Posted: Sat Mar 01, 2008 7:23 pm
by ericthepoolboy
So I found this website while I researching for an engineering project and I though I would share my final project with you guys. The project was to launch a water balloon with about half a liter of water about 100 feet on to a target with out popping it. Kinda lame huh? So I wanted to build something that was capable of the specification but also able to go above and beyond.

The final design called for a 60 gallon air tank, 4" PVC barrel that is about 8' long, six 1" electric sprinkler valves, and misc. piping.
The tank has a max pressure of 200 psi, and the valves have a max pressure of 150,
The six different valves can be such off individually if you want to reduce the total air flow entering the barrel. They can also be delayed for a mili-second or so, so that the valves open sequentially and slowly accelerate the balloon through longer barrel.

Also the whole tank can be lifted in the front to change the launch angle of the cannon. This is accomplished by the car jack that is welded to hinges and then mounted to the frame and tank. It can go to about 50 degrees.

When finished we were able to send a water balloon about 900 feet without popping it. This was at 30 psi and all six valve opening. We could have gotten it farther if we had attached a longer barrel but we didn't have anywhere that was open enough for a longer shot.

The barrel is also the perfect size to fit a softball in. the soft ball went about 1400 to 1500 feet with 40 psi in the tank.


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Posted: Sat Mar 01, 2008 7:29 pm
by ghostman01
wow thats one hell of a air CANNON all the rest are puny compered to this thing

Posted: Sat Mar 01, 2008 7:31 pm
by Pyro Ninja
OK, that is "BIG"
Good job with it, The paint looks nice
A bigger barrel may give you better performance

Posted: Sat Mar 01, 2008 7:33 pm
by bigbob12345
Wow that is huge modify the sprinkler valves and you will see a huge increase in performance.

Posted: Sat Mar 01, 2008 7:39 pm
by DYI
Let me be the first to say that this thing is absolutely ridiculous. In a very, very good way :D

This cannon has the largest chamber of any on the entire site, and could become one of the most powerful if you attached a bigger barrel to it, and got a larger porting valve.

With 13 840ci of chamber volume, if you attached a 6" porting piston valve and a 6" x 50' barrel, you'd be looking at small punkin chunker type power (over 60k ft/lbs). As is, you're just wasting insane amounts of air. My cannon with less than one gallon of chamber volume is getting twice the power per projectile mass and size, even with very generous valve estimates on your gun.

Posted: Sat Mar 01, 2008 7:47 pm
by th3p0p0
:shock: wow thats all i can say.

Posted: Sat Mar 01, 2008 8:07 pm
by Sticky_Tape
Too much overkill please don't quote my cannon. it looks cool but why so many solenoid valves? You definently need a longer barrel.

Posted: Sat Mar 01, 2008 8:30 pm
by brogdenlaxmiddie
I must say, that this is an absolute monster! My favorite part is the control panel, with the keys and switches..... A most definite god of cannons.

Posted: Sat Mar 01, 2008 8:36 pm
by Cosmic Muffin
ok i love that beast but modding the valves is the way to go and do you really need so many?. it needs a huge barrel like 10 metres though :twisted:

Posted: Sat Mar 01, 2008 8:40 pm
by Lentamentalisk
Please tell me you have the valves shut closed almost instantly or you will lose sooooooo much air... The ideal chamber to barrel ratio is about 1:1. By my rough guestimate, you have about 1:1000000000 lol. That is an insane cannon!
Really nice job!

Posted: Sat Mar 01, 2008 8:41 pm
by pizlo
Son of A BITCH!
If you had the funds for that, why didn't you just buy 3 supah valves?
or better yet build your own huge pistons.

Posted: Sat Mar 01, 2008 8:45 pm
by Lentamentalisk
Obvioulsly he was going for electric triggering, and for a good reason, you dont want to vaporize the balloon in the barrel. However you could have made your own much bigger piston valves, and piloted them with the sprinkler valves.

Posted: Sat Mar 01, 2008 8:55 pm
by potatoflinger
That is one huge cannon! The paint job is great! One suggestion I would like to make though is that after you finish the challenge, you should convert the gun to a triggered burst disc cannon, with at least a 2" union, and get a really long barrel (20+ feet) that way you will get a ton more power out of it.

The cannon will work very well for your challenge, especially since you have the valves open at different times to avoid obliterating the water balloon. This cannon is just amazing, hope you do well in your challenge!

Posted: Sat Mar 01, 2008 9:10 pm
by starman
Very nice, very wicked looking machine. If your distance measurements are correct for something the mass of a softball, over a quarter mile, a wicked performer as well, even without optimized barrel length and piston valves!

Your air tank is way overkill but what the heck, I wouldn't change a thing! Nice performance, nice presentation.... impressive indeed!

Lastly, will you have to go trade for a bigger truck to haul it now? Or put a hitch on the thing and tow it like a trailer....:)

Posted: Sat Mar 01, 2008 9:16 pm
by bluerussetboy
short and thick does the trick :D