Fractional Gears

Fractional Gears is a gear set that features a gear with "half-fold" rotational symmetry. A gear with 180-degrees symmetry is said to have "two-fold" rotational symmetry. The green egg-shaped gear has 360-degrees "one-fold" symmetry. For a 360-degrees turn of the green egg-shaped gear, the smaller red gear rotates by 720 degrees. Following the earlier naming logic, this gear has half-fold rotational symmetry.

In order to make the cardioid-like gearing, the red gear has two layers. The teeth pattern continues from the bottom layer to the top and back to the bottom. In order to fit the bigger red bottom, the green gear has a cut out to make things fit.

Watch the YouTube video.
Read at the Shapeways Forum.
Read more at the Non-Twisty Puzzles Forum.

Please order a 3D-printed do-it-yourself puzzle kit from Shapeways at this page (check with Oskar about screws and stickers), or contact Oskar directly if you are interested in obtaining a fully colored, stickered and assembled sample of this puzzle.