The Technic models in "Simple Machines" demonstrate basic configurations of gears, shafts, pulleys, turntables, connectors, and the like and show readers how to create small, elegant machines like cranes, operable doors, motorized cars, a rubber band-powered rocket launcher, a hand-cranked drag racer, and even musical instruments.

Gears -- Shafts and connectors -- Gear combinations -- Gears in a turntable -- Gears in series -- Angles gears -- Worm drives -- Chains and treads -- Rubber bands -- Rack-an-pinion gears -- Moving to and fro -- Moving freely -- Going the distance -- Motors and gears -- Building in any direction -- Strong combinations -- Two simple chassis -- Doors -- Pulley systems -- Rubber band power -- More uses for gears -- Making music.