A working model of a planetary gear set. This model also allows the gear set to be exploded which gives a better view of the internals. This is accomplished by pulling the ring and sun apart. In its compressed or exploded form, the gear set is functional.

The ratios are as follows: Sun to Carrier: 3.3:1 Carrier to Ring: 0.70:1 Sun to Ring: -2.3:1

http://auto.howstuffworks.com/automatic-transmission3.htm

1)Print all pieces 2)Sand pieces smooth to ensure proper mating and free movement. Extra attention needs to be paid to sanding the Carrier's working surfaces. 3)Tap or thread the small holes in the top of the Carrier for the M3 screws. 4)Press the Carrier onto the shaft inside of the Ring. This press should require a little force in order to keep the Carrier from coming off the end but should telescope smoothly. 5)Add the 3 Planet gears and then the handle. 6)Secure with the M3 screws 7)Press the planet onto the Carrier shaft. Again, the beginning press fit should be tight but loosen up to telescope smoothly.