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42: Wanted: Non-Circular Planetary Gear Set

Posted on Sep 2, 2014 by in No Limit

Wanted: A non-circular Epicyclic gear system, with at least 3 planetary gears.

Bounty: ($200 + $50 * Months After September 2014) Zen Credits.

Fig 1. Wooden Non-Circular Planetary Gear Set

This is not a standard contest. Similar to Contest #12, we don’t know if what we’re asking for is possible, and thus there is no deadline. The contest is over once an object is successfully made, or the contest continues forever. The bounty will increase by $50 each month, up to a maximum of $1000 on January 2016. As always, Zen Credits are exchangeable for half of their face value in Bitcoin.

Fig 2. Magnet gears using frame. Click for source.

There are a few examples of gear systems made with Zen Magnets around the internets. Click on Figure 2 above to see the full video which contains a few more examples. Making subunits that can contact and affect other subunits is already a mild challenge.  But unlike most existing magnet sphere gear systems, this planetary gear  should not be supported by other materials, and the gears will not be round.

Fig 3. Planetary Gear Diagram



      • Minimum 3 planetary gears.
      • Planetary gears must be non-circular, meaning magnets that make up the edge of the planetary gears must not all be equidistant from the center of the gear. (See Fig 1)
      • The Sun Gear must be able to be held by hand, and support the weight of the entire gear system. (Like Fig 1)
      • The gear system should not fall apart, or otherwise become broken, if held horizontally by the sun gear.
      • By applying force downwards on one end of the Ring Gear, the gear system should operate without magnets becoming dislodged. (Not like Fig 1, which shows force being applied upwards.)
      • Zen Magnets Only. Use however many are needed.
      • Must be able to show how to recreate the structure.

Similar to the Gyroid Contest of Nov 2011, your peers will not be the judges in this contest. If you think you’ve figured out how to create a planetary gear set, tell us via our Contact Form with “Contest 42 Entry” in the subject line. We’ll reproduce your work to confirm it’s legitimacy. If you the genius that is able to complete this contest, your bounty will paid once we are able to successfully recreate your design.