About

Great Gears is a beautiful and tricky puzzle manufactured by Tomy. It consists of 7 disks in a hexagonal arrangement, one in the centre with 6 disks of the same size around it. Every disk has 6 pockets on its edge. Each pocket contains a ball bearing, except for exactly one pocket which is empty. The top disk is red, and the six ball bearings that are coloured red belong on that disk. Similarly there are 6 blue balls that belong in the blue disk at the bottom right, and 6 green balls belonging in the green disk at the bottom left. The 23 remaining bearings and 4 remaining disks are not coloured. There is a wheel on the side of the puzzle. Turning the wheel in one direction will turn all the coloured disks and the centre in the same direction, and the other disks in the opposite direction. When the disks are rotated so that the empty pocket is at a point where two disks touch, then the ball in the adjacent disk can be moved over to the empty pocket by tilting the puzzle. The fact that the disks cannot be controlled individually makes it a remarkably frustrating puzzle to solve. You will often find that the last ball of a particular colour is hard to solve because the gap, the coloured ball and the pocket where it belongs don't line up. As soon as you manage to empty the pocket, it will not line up to the coloured ball in the adjacent disk. The puzzle was patented by Koichi Minami and Tohru Nishimiya on 28 August 1984, US 4,468,033. The number of positions: There are 6·7=42 pieces (including the gap), consisting of 6 red, 6 blue, 6 green, 23 silver, and one gap. This allows for 42!/(23!·6!3) = 145,608,355,684,298,707,200 = 1.46·1020 positions. If your browser supports JavaScript, then you can play Great Gears by clicking the link below: