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Registered Member #952
Joined: Mon Aug 13 2007, 11:07AM
Location: Finland
Posts: 388
Ok, so here's my high-energy homemade airgun. So it consists a 1,5L pop bottle, a car valve stem, a ball valve and a barrel. The ball valve is closed, and the bottle is pressurized through the car valve. A projectile is put into the barrel and the barrel is screwed to the ball valve. Then the ball valve is opened and the air pulse accelerates the projectile through the barrel.
My barrel is currently a bit too short to efficiently use all the energy stored in the bottle. Wait until I get a longer barrel... For a projectile I use a small piece cut from an eraser and covered with tape to fit tightly in the barrel.
I've recorded a short video of it shooting a cardboard box. There's also a slo-mo gif animation to see what actually happens.
You can also post your own pneumatic toys in this thread.
Registered Member #952
Joined: Mon Aug 13 2007, 11:07AM
Location: Finland
Posts: 388
I've made some measurements with the air gun. I measured the speed with 3.5 meters distance between the gun and the target. The average speed with a 12 gram projectile was 20.5 m/s. Not too bad! I calculated the kinetic energy of the projectile and it's 2.5J
Registered Member #964
Joined: Wed Aug 22 2007, 12:39AM
Location: Stockton, CA
Posts: 134
You could make this pneumatic spudgun a heck of a lot more powerful, just make a better valve like the modified sprinkler valve These open lots quicker than your ball valve can and you'll get better performance =)
ps: If you feel up to it, you could take it another notch higher and build your own piston valve. look around the "How-To Database" at that website, there's tons of diff. ways to make them
Registered Member #952
Joined: Mon Aug 13 2007, 11:07AM
Location: Finland
Posts: 388
Spedy wrote ...
You could make this pneumatic spudgun a heck of a lot more powerful, just make a better valve like the modified sprinkler valve These open lots quicker than your ball valve can and you'll get better performance =)
ps: If you feel up to it, you could take it another notch higher and build your own piston valve. look around the "How-To Database" at that website, there's tons of diff. ways to make them
Actually the ball valve can be opened pretty quickly And I like to Keep It Simple, so no valve modding. The pressure in the vessel quite forces the ball valve to open.
Registered Member #1361
Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305
Nice cannon! If i ever made one of these, i would design it to fire little hard orange berry things, they are all over the place here. Going by yor words, it seems pretty powerful. Got any vids/pics of the projectile going through something?
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My Airgun
And I like to Keep It Simple, so no valve modding. The pressure in the vessel quite forces the ball valve to open.
You also seem to have noticed that the all-mighty hot glue doesn't work in this kind of purpose.