Circular motion from the motor is changed into a sort of back and forth motion through the linked levers.
The actual "board" is two 16 beams and two round blocks.
The 8 beam is connected with the gray pins that are axles on one side.
Note the positions of the cams.
Place the motor block from Green instruction G so that the blue plate
is in the place shown
and the 4 axle goes through the two cams at the top hole.
Be careful that the axle is flush with the cam and does not extend out.
Example using newer motorized machine set.
Click pictures for larger version.