Sariel's "Gears Tutorial" -- http://sariel.pl/200...gears-tutorial/ . "A complete tutorial on Lego gears, their advantages and disadvantages as well as the basic laws of mechanics that apply to them. Updated on February 19th 2010."

"Physics of Lego" -- If you click on the menu along the left side of the following webpage, it covers "Motors, Ratchets, Multiplexors, and Pneumatics" : http://www.mapageweb...sics/index.html .
Jetro's "LDraw Tutorial" on TechnicBRICKS -- Part 1 ( http://technicbricks...ial-part-1.html ), Part 2 ( http://technicbricks...ial-part-2.html ), and Part 3 ( http://technicbricks...ial-part-3.html ).














