This is a "lost project" because it hasn't been posted anywhere until now. Unlike most of my projects, this one uses no electronics. It's a catapult I made a while back that fires 50 small projectiles (axle pegs) over a wide area. Here's the YouTube video I just posted:
The YouTube video explains what it does, so I'll launch right into an explanation of how it does what it does.
This catapult gets its power from rubber bands, but unlike most catapults the power is transferred through gears. The rubber bands pull back on one lever arm which is connected to a 24 tooth gear. The 24t gear meshes with a 40t gear attached to the main arm. This setup helps to maximize the power of the rubber bands.
Because the small arm has rubber wheels protruding from it, it contacts and stops the main arm just as it reaches a 45 degree angle. This maximizes the range by releasing the projectiles at the best possible time.
The 50 projectiles are held within the holes of 5 parallel beams running up the main arm. Because the axle side of the axle peg projectiles is in the hole they smoothly release most of the time, but sometimes they stick and don't fire or fall short. If this were to be used as a practical weapon, there would have to be a way to keep projectiles from exploding unless they fell far enough away from the catapult.