Gear Cube Solver

How to read your cube into the solver

Pick a colour, then tap the squares that show it. Hold the cube with one face toward you: that is Front, and whatever points at the ceiling is Up. To see the Right, Left or Back, turn the whole cube on the table so that face comes round to you, keeping Up on top. For Up, tip the cube toward you; for Down, tip it away. Paint each face exactly as it looks from there.

The edges are drawn round because on a Gear Cube they are gears. Paint the colour each one shows on that face. If a gear is tilted, take whichever colour covers more of that side; the solver only needs to know which two colours each gear carries, not which way round they sit.

Each colour has to appear on exactly nine squares, and the counter above the net turns red until it does. Which way up you hold the cube does not matter, and neither does your colour scheme. The solver works both out from the corners.

What the moves mean

A Gear Cube only turns in half turns. A quarter turn jams it, because the gear teeth would end up out of step with the ones they have to mesh with. So every move here is a half turn of one outer face, named by its first letter: R is the Right face, U is Up, F is Front, and so on.

A plain letter means clockwise as you look straight at that face. A letter with a dash, R', means the same half turn anticlockwise. Hold the opposite face still while you turn. The middle layer between them follows by itself, a quarter turn, and that is the whole trick of the puzzle: both directions leave the face you turned looking the same, and only the middle tells them apart. Get the direction right and the middle goes where the solver expects.

The face to turn next is outlined on the net, and Step walks the solution one move at a time with the net updating as it goes.

Why the gears come last

When every piece is in its place, the Gear Cube can still look wrong, because the edge gears turn on their own axes as they travel. Getting an edge to the right place with the wrong rotation is the characteristic Gear Cube failure, and it is the last thing to fix.

The four edges in a middle layer always share the same tilt, and there are only three possibilities. Four half turns of one face bring every piece back exactly where it was and move that layer's tilt on by one step, which is why the fix is four turns, and at most four more. It never disturbs anything else, so there is nothing to undo.

The solver leaves this step to you rather than asking you to describe the tilt, because which way a gear leans is hard to read accurately and easy to read wrong. Counting to four is not.

How hard is the Gear Cube, in numbers

For all its gearing, the Gear Cube has only 41,472 positions you can tell apart. A Rubik's Cube has over 43 quintillion. No position is more than twelve half turns from solved, and the colour part, which is all this solver has to work out, never needs more than eight.

Those figures are not taken on trust. They come from Jaap Scherphuis's analysis of the puzzle, and the model this page runs on was checked against them before anything was built: it reproduces 41,472 exactly and the same twelve move maximum, and it solved three thousand random scrambles, held every way up in every colour scheme.

More on this puzzle

How the gears drive the middle layer, why the Gear Cube was first called the Caution Cube, and how to solve it by reasoning rather than memorising are all in the Gear Cube guide.

We do not make a Gear Cube: it is a moulded plastic mechanism with internal gearing, and our puzzles are 3D printed pieces with nothing that moves inside. If what you liked was a cube with one clean insight rather than a memorised method, that is EcstaTIC, two pieces and a single rotation, from the turning interlocking cubes. The rest of the shelf is cube puzzles, and there are more solvers on the puzzle tools page.