Look closely at the drawing below. When you push down on the see-saw this picks up a pendulum weight. This unbalances the wheel.
The wheel begins to turn counterclockwise. Now, allow the see-saw to pivot back down for the next weight and start the process over again to continue turning the wheel. Notice that the pivot is off centered. Can you find the method to operate the see-saw by using only the power output from the wheel? You can move the see-saw around to any position, and add any components you wish. One idea can be seen
here.
Engine drawing.
