(1) Fix the small motor on the board. (2) Take a 6 mm long round pencil rod, remove the lead, and press it with triangular steel to form a small pulley. (3) Glue the small pulley to the small motor shaft with latex. (4) A large pulley with a diameter of 20 cm is made of two layers of plywood. (5) Put the big pulley on the plate and install the crank. (6) Put the rubber band on the small pulley and the big pulley. (7) Connect the 1.5V bulb to the two connection points of the small motor. (8) Shake the big pulley crank quickly to make the small motor generate electricity and light the small light bulb.