PRINCIPLES: Illustrates mechanical advantage (or lack thereof) using pulleys, shafts, a crank, and adjustable moment arm.
CONCEPT: Large toy construction crane (approx. 3 to 4 ft tall). Made out of Rubbermaid-like plastic material for some give but basically rigid. Modular construction allows cross-arm, crank, and pulleys to be moved around to various positions and various angles in order to explore different combinations and effect upon modular construction. Parts fastened using large scale plastic screws or pins that a child can easily manipulate
COMMENTS: Should be easily constructed out of molded plastic (except for string and hook.) No pieces should be a choking hazard (unless hook comes free of the string.) Base will be heavy, perhaps even contain something like sand or water to make it massive enough to prevent tipping and possibly injuring kids. Meant for ages 4 and up.