Hover over the menu bar to pick a physics animation.
The animation produced here is an attempt to educate the user about gear ratios and is not intended to provide design information for durable and low noise gear boxes. The most important fact about gears is that their relative rotational speeds are defined by ratios of the numbers of gear teeth in the assembly. For an assembly with just two gears, the speed of the second gear is defined by
`"rpm"_2=("teeth"_1)/("teeth"_2)"rpm"_1`
where rpm stands for revolutions per minute. The direction of the second gear's rotation is always opposite that of the first gear's rotation. For three or more gears the speed of the third depends on its number of teeth as well as that of gear 1 and gear 2. For and internal gear like gear 1, the direction of the external gear that it drives is the same as gear 1. For more detailed information on gear design see Simple Gear DesignThis causes each press of the Start button to advance gear 1 by about 0.02 radians
Gear 1 teeth/Internal teeth
nTeeth3/nTeeth2*gearRatio13
(nTeeth1/nTeeth3)*gearRatioExtInt
gear 1 teeth/External teeth
External teeth/Internal teeth