Released in 1982 from Tomy, the Great Gears mechanical puzzle was both challenging and stylish.
The 4.5-inch x 4.5-inch game comprised seven gears placed in a hexagonal arrangement – one gear in the centre and the remaining six gears positioned around it. Each gear held up to six metal ball-bearings in a series of pockets cut into its edge. Three of the disks were coloured (red, blue, and green) and had matching ball bearings. There were 41 ball bearings in total and 42 pockets to hold them.
The game’s object was to use the thumbwheel on the side of the game to rotate the set of gears and try to get each ball into a gear of the same colour. Turning the wheel in either direction caused the centre gear and the three coloured gears to rotate in one direction, while the remaining gears moved in the opposite direction. By rotating the disks and tilting the puzzle so an empty pocket touched another disk, players could transfer a ball bearing from one gear to another.
Sound complicated? It was! The lack of control over individual gears required puzzlers to sequence their moves and always keep track of the location of the empty pocket. The sheer number of moving parts and pieces resulted in myriad possible gear/ball-bearing combinations.
The design of Great Gears was so unique that the puzzle itself was patented in 1984 by its inventors, Koichi Minami and Tohru Nishimiya. Around that time, the puzzle disappeared from store shelves.