Desk Top Slingshot Cannon

OK, as you may know I am planning to make a petanque ball shooting carriage mounted slingshot cannon. The goal is to shoot the 3" (8cm) (800 gramm heavy) steel ball with 70 m/s, almost 2000 Joules of energy.

So I wanted to do it like the Mythbusters and started out with a 1:10 model of it. This means the ammo has got to be 8mm steel as the petanque ball is 80 mm steel.

I have to say that working on such small mechanisms is not easy, in fact it is a lot easier to work big size. I am not totally happy with the precision of the job, but it is functional, even dangerously so. It fires 8 mm steel balls through a few layers of tough cardboard (moving boxes).

I have changed the lock mechanism, made it more sturdy by adding two more lock arms on the opposite side. This gives the lock arm much less play.

Have completed the model weapon now, including a second winch to adjust the shooting angle. This needs some finishing work and is ready to sit on my desk!

The "real" version will be almost 4 meters in total length.

Here is the video:

http://www.youtube.com/watch?v=TZ9keWOP2To