In this step I create a hand crank generator to power the conveyor belt.  Let's start with a MG995 servo motor.

Remove the screws and the back plate.

Cut the three wires (under the circuit board) that lead to the potentiometer.

Remove the potentiometer--it is one of two items that prevent full rotation of the gears.

Open the gear cover. On the large brass gear, there is a pin protruding. Lift that pin out (it should remove easily).

Remove the circuit board by cutting the two red wires that lead to the motor.

Solder connecting wires from the motor (about 10 inches long).

Close the motor and screw everything back together.

Fasten the crank to the servo horn, then secure the motor in the servo mounting bracket. Attach the crank to the servo motor shaft.

Screw a terminal block to the plywood base. This block will allow little makers to move the wires around if they elect to mess with them.

Connect the wires from the servo motor (generator) to the motor. The belt should move when you turn the generator. Switch the red and black wire positions if the direction of cranking does not match the movement of the belt.