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A pentagonal version of Gear Fold.
Only days after Gear Fold its inventor presented this pentagonal variant which was proposed by Bram Cohen. It is a gear train of five seven-teeth gears.
Compared with its predecessors the gears can't move all at once because there is an odd number of gears. Moreover, it is locked by a piece in the center.
Pentafold can be folded open in five directions. Once folded open, three gears can turn. This enables to scramble the puzzle.
"God's number" for this puzzle is five, i.e. it can always be solved in five moves. Bram Cohen found a generic easy-to-remember solution that requires at most eight moves.
In November 2014 Oskar presented an improved version. In the first version cheating was possible with the help of a bit of force.
Diameter: 54 mm
Thickness: 27 mm
Weight: 58 grams
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