The LEGO Power Functions Idea Book: Machines and Mechanisms shows off small projects to build with LEGO's system of gears, motors, gadgets and other moving elements. The book is filled with hundreds of buildable, clever mechanisms that demonstrate a key technique or mechanical principle. Follow along and build rack-and-pinion steering systems, sliding doors, grasping claws, ball-shooting devices of every sort. And just by building, you'll explore the principles of simple machines, gearing, power translation, and more. Imagine. Create. Invent. Now, what will you build?