Here is a scale model of a steam crane. Many of the small parts are made from found materials such as copper staples, old gears, recycled wood, beads, and metal tacks. A motor moves the machine forward. While one hand-operated crank raises or lowers the boom, the other crank unwinds the hook and cable. Dimensions: 4.5 inches wide, 8.5 inches long, and 20 inches tall.