![](/images/motor shaft.jpg)
Mount a bushing on a motor shaft, and use a pencil to support a spool. The spool should be able to rotate. Show students how a rubber band can be looped over both the shaft and the spool. If the rubber band is stretched slightly, turning the motor shaft will also turn the spool. Have a student help you show this by rotating the bushing by hand while you hold the motor and spool. See diagram below. The two pulleys are the motor shaft and spool, and the rubber band is the belt.