I teach Forensic Science for the Criminal Justice program at my college - and that includes a section on Firearms & Ballistics. I’m moving into a new lab in the fall, and will finally have the length and height necessary to run some simple indoor ballistics (mostly trajectory) demos and labs. I’ve just started searching for - and haven’t had much luck finding, btw - what I used to have as a kid … a gun that shoots ‘ping pong balls’. Yes - they now make "nerf’ guns & canons, and I may end up having to fall back to that option. However - I’d really like to use ping pong balls. PP balls have the added advantage of being able to be filled with various substances, thus changing the weight of the projectile:)
Does anyone know of a source? The perfect gun would have the following characteristics:
- Variable power settings to allow for variable velocities
- Consistent, repeatable velocities (compressed air, or electric motor drive?)
- Under $100
- Something sized so I could build a cradle for it to adjust the angle of the shots.
Ideas?
TIA
john
I don’t know about ping pong balls but I have it on good authority that SteyrAUG is a subject matter expert on all things concerning homemade tennis ball cannons. You might want to PM him so he can help you out with a PVC project.
My friends and I had a hilarious amount of success in high school making a basketball playing robot (that used ping pong balls). A paper towel tube barrel and a pair of simple electric motors, cheap plastic wheels and some rubber bands can launch ping pong balls at around 80fps at the muzzle. We were able to make a pretty simple cupola for the thing, and a really ghetto paperclip rheostat worked just fine for adjusting velocity - our biggest problem for tabletop basketball was getting too much power (we gave up and drained three pointers from the other side of the table).
Just set up the motors horizontally opposed to it squeeze-shoots the balls, and as long as the motors are spun up to a consistent RPM the velocity we got was really stable, and with the width trimmed out at the widest point we could fire multiple in fairly short order with the same velocity.
Just watched an episode of myth busters where they built one. It looked to be an easy build.