Jr. Scientist Dynamo Crank Helicopter Kit Teach the young 'uns all about generating electricity with this Jr. Scientist  dynamo kit, then let them build a tethered helicopter and a turtle that jumps up and down using electricity--unlike real turtles, which don't jump all that much. Includes a crank dynamo with a small DC motor, plus the parts for the helicopter and turtle, both operated by a pager motor/gearbox. A 67-page manual covers static electricity, batteries, magnetism and electricity generating, plus instructions for other experiments and a cartoon bio of Wernher von Braun as a junior scientist.