Lego© compatible Cannon XXL (8 m/s)

This Cannon shoots 9,5 mm steel balls with a velocity of about
8 m/s means arround 0,1 Joule. That's enough to smash interlocked
bricks of Lego castles, pure fun ! The cannon can be cocked by pressing in a
a stick (left over from the Ball Point Pen ?) or pulling the plunger, fires
while pressing down the trigger board

SERIOUSE WARNING: Make shure that EVERYBODY
- in general don't shoot at humans and animals
- don't shoot pointy or sharp projectiles
- don't shoot ANY projectiles (ex. c