Pythagoras Gears

Pythagoras Gears is a set of nine 7-teeth gears contained in a 27-teeth annulus gear. It is a proof of concept of this gearing mechanism with no obvious application. After several failed attempts (here and here), Oskar managed to design a planetary gearing system with more than one layer of free-hanging planet gears. The solution was to have nine 7-teeth gears placed in a 3x3 square configuration. Some fudging was required, as the gearing ratio 7/27 does not have a square-root-of-two in it, as required by Pythagoras famous equation a^2+b^2=c^2.

Watch the YouTube video.
Read at the Shapeways Forum.
Read more at the Twisty Puzzles Forum.
Read more at the Reddit Mechanical GIFs.

Please order a 3D-printed do-it-yourself gear 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 contraption.