This animation explains the principles of automatic transmissions that use planetary gears. The rotation of the sun gear is constant on 2 animation parts. But you can choose the rotation of the sun gear yourself, and the remaining transmission will rotate automatically. Also you can change the speed of rotation (sun gear) at the same time controlling Float Limits of the gears. In the frames 0 to 100 the animation shows 1st and Reverse gears. In the frames 101 to 200 the animation shows 2nd and 4th gears. In the frames 201 to 300 the animation shows 3th gear. This model gives you the ability to vary the linkages in different combinations and to understand how their work. The mechanism was created in 3ds max. The animation is only in max and fbx ( keyable ) files. Enjoy!