Gear Fit

Gear Fit is a gear-matching puzzle. The object is to place the two oddly-shaped gears over the two seven-pointed-star shafts such that they rotate freely. When gears are placed incorrectly, they won't fit, or the rotation will block. Hidden inside the frame is an identical set of gears that control the rotation of the shaft. The system will turn only when the placed gears match the hidden ones. 

When one naively tries tries all possible combinations, then this may take up to 7x7x8=392 attempts. However, when you realise that the placement of one gear determines the other, then only 7x4=28 attempts remain. One can reduce this number even further, when checking at which orientation one shaft turns the fastest, and what this means for the orientation of the gears. Hence, this puzzle is quite solvable with some clever thinking.

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.