Ping Pong Cannon

[Stuey]

http://blog.tinyenormous.com/2009/09/03/lethal-pneumatic-ping-pong-ball-gun/

Holy cow - this thing sends ping pong balls through particle board. I wonder what it can do with golf balls!

 

[bchee]

that's no fair, they are water-filled

I don't know the mass and velocity equations but I think they apply here

BTW it reminds me of those *** shows where women shoot them out of their lower parts
http://community.discoverychannel.co.uk/eve/forums/a/tpc/f/95010646/m/543103501

 

[Stuey]

By my calculation, the water-filled ping pong ball should weigh about 1.2 ounces. Don't know what to do with that info, though.

 

[evil16v]

It goes to show how damn stupid gun laws are. Any jackass can make some kind of gun in his own shop. There are so many ways....You will never stop the guns, you have to correct the peoples behavior instead.

 

[bchee]

When I first read it I thought you could kill someone with a plain air-filled ball.

Of course, when you add that mass, it makes a huge difference.

I bet in tournaments the balls travel faster than 60mph

 

[Stuey]

When I first read it I thought you could kill someone with a plain air-filled ball.

Of course, when you add that mass, it makes a huge difference.

I bet in tournaments the balls travel faster than 60mph

I'd bet that getting hit by an air-filled ball would still be plenty painful, if not damaging.

 

[DonL]

Okay, let's see what we can figure out for ballistics. Bullets are weighed in grains and there are 7000 grains in a pound. Stuey estimated the weight at 1.2 ounces and that seems reasonable to me, I figure that to be 525 grains.

(7000/16)*1.2

Just for some numbers, let's say this thing is twice as fast as a paintball gun, I can reference that as 300 fps, so 600 fps.

Momentum = Mass * Velocity

525 * 600 = 315,000


For comparison a 45 ACP, is 230 grains at 900 fps

230 * 900 = 207,000


A paintball is 0.32 ounces or 140 grains at 300 fps

140 * 300 = 42,000


Without a chronograph this is just a guess, but I'd say that thing deadly.

 

[Bolster]

Doesn't it matter, the surface area over which it's spread out? When I fire a .45, the **** gives a good jolt to my hand, but it's spread out over a couple square inches (and also spread out over several fractions of a second, too), as opposed to the slug.

 

[nissan_crawler]

I built one at home out of 3" oilfield casing, and 18" steel pipe for the chamber. Spark plug/coil. electric fuel pump and injector from a 2.9 ford...

Particle board? Pffffttttt.

Oh, and if you put enough cardboard behind it so it doesn't disintegrate, you can put a tater through a car door...

It had a meeting with the torch when I moved.

 

[-B-]

Way over built and complicated you can easily get a paintball gun to do the same thing and it is even marketed to LEO.

pepperball teconologies uses plastic shelled 'paintballs' so thay can take the higher velocities 400-500 fps the energy they can produce on impact can be deadly depending on round and situation.



the FN 303 valve system and design come from one of the great innovators in paintball


you do realize there are real quality air guns that actually achieve 1200fps with a .22 cal pellet.

 

[DonL]

you do realize there are real quality air guns that actually achieve 1200fps with a .22 cal pellet.

But a .22 cal pallet is only about 14 grains. So the multipliers are a lot lower.

14 * 1200 = 16,800

Remember the 600 fps for the ping pong ball was a guess. You can do the what if for 800, 1000, 1200 fps.

I can't answer how the increased surface area effects things. You are still transfering the same total energy.

How much does the ping pong ball deform on impact?