Serpina Electromechanical Wooden Rolling Ball Clock

"Dust on the seesaw destroys the theory."

These clocks are working without a pendulum. Instead of the pendulum a ball is rolling down an inclined plane, for which it takes 20 seconds. Then the Seesaw tends to the opposite direction and the process begins again.

This clock type is relatively unknown although the first examples were built in the 17th century. Serpina was inspired by the design of Sir William Congreve from the early 19th century.

Rolling ball clocks are primarily great entertainers. Although Galileo Galilei already discovers, that a ball needs on an inclined plane always the same time for the same distance. In practice, however, all rolling ball clocks have a problem with the accuracy, because dust on the seesaw destroys the theory.


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3 Responses:

  1. Dan Sylveste says:

    I really love these autonoma, but if the designers would just go one step further (an embedded system with a NTP client) then it'd go from being a neat-but-irritating toy to a real practical thing.

    The tilt angle of the platform could be dynamically altered to keep it accurate within its resolution (20s) easily enough, I think, or even simpler the rotation of the platform could be delayed for a few milliseconds after the ball hits the contacts - but for that it'd have to be designed to gain time.

    Still neat.

  2. James says:

    Temperature and humidity are probably greater sources of perturbation than dust.

  3. James Broadhead says:

    There's a great example of one of these, built by Congreve himself, in the British Science museum

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