Non-Transitive Gears is a puzzling mechanism based on an idea by Alexander Poddiakov. In his article "Intransitive Machines", Poddiakov writes about non-transitivity, wher A is larger than B, B is larger than C, and C is larger than A. There exist many examples, including non-transitive dice, and non-transitive election results. Poddiakov also showed an example of a set of three gears that are non-transitive. When two of these are put against each other, then A spins faster than B, B spins faster than C, and C spins faster than A. See also Poddiakov's post at trv-science.ru with lots of interesting responses.
A physical implementation would not allow Poddiakov's gears to be put all three together, as then the mechanism would jam. A solution was the addition of three ratchets. Whichever of the three knobs you turn, one of its neighbours will turn 2x faster and the other 2x slower.
Watch the YouTube video.
Read at the iMaterialise Forum.
Read more at the Twisty Puzzles Forum.
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Oskar van Deventer
Oskar Puzzles offers mechanical puzzles and objects that can only exist thanks to 3D printing technologies. All designed by M.Oskar van Deventer.