Compound Machine Project

My daughter recently needed to complete a science project which involved using household items to build simple machines and then connecting them together to form a compound machine. The goal of the machine was to be able to pop a balloon.

The compound machine needed to consist of the following simple machines:

Gears
Incline Plain
Lever
Pulley
Screw
Wedge
Wheel and Axle

The process for our machine starts with a pencil sharpener (gears) winding a string which lifts a platform. This allows a hard drive platter (wheel and axle) to roll down a half cut piece of PVC pipe. The hard drive platter is connected to a piece of string which is pulled as the hard drive platter rolls. The pulled string moves a dowel up through a hole in another piece of pvc pipe pushing a golf ball through the tube. The golf ball lands in a plastic cup attached to two pulleys which move a lever into a "down" position (The level is held in an up position by a large screw). The lever held a piece of plastic which is released by the lever change and swings and pushes a toy train piece down a set of tracks. The train piece has a needle (wedge) connected to it which then runs into a balloon - popping it!

Click on the title above for a closer look at the machine itself. This brings back memories of the game Mousetrap!