Planetary gear has good balance between the size and gear-ratio. Compact electric screw-driver may have the planetary gear inside. This planetary gear can be use in the DIY projects which need high torque and compact size. The drawback is that many gears inside the planetary gears produce much noise.

This screw-driver has a motor and a planetary gear inside. It also had accumulator battery.

Remove the housing and disconnect the gear from the motor.

Planetary gear has a number of gear wheels. The bit-holder and the motor is not needed. But the motor’s axis with the gear is needed.

Disassemble the motor and carefully release the axis from other motor parts.

Only following planetary gear parts are needed.

Clean the gears and the planetary gear is ready to be used in the project. The gear ratio for this one is 1:20.