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Brimming over with whimsy and fun
full of the mind-blowing images that have captured the imagination of millions
Up or down
scientific knowledge
Heavyweight acid-free archival-quality 128 gsm paper
SpringBots: 3-in-1 Spring-Powered Machines beach-sand Brimming over with whimsy andBuild a motorized robot, race car, and countdown timer all that run without any batteries or electrical power! The secret behind these fascinating machines is a power source called a mainspring a spiral shaped spring that stores up energy when wound up by hand, and then converts that stored energy back into motion when it discharges. The mainspring inside the robot turns gears which enable it to march forward on two legs. The race car zooms across the
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