Mechanical devices can change one form of force ... and the velocity ratio has been calculated as 3. Smaller gears with fewer teeth turn faster than larger gears with more teeth.

Gears can change the direction or the speed of movement. As there are teeth around the edge of the gears they grip together and so can withstand a greater force, enabling them to move large items ...

Experience the ingenuity of a wind-powered Lego gear machine that showcases a range of unconventional gear types never before made by Lego. Powered by a vertical wind turbine, this machine rotates ...