As one gear turns, the other gear must also turn. Where the gears meet, the teeth must both move in the same direction. In the diagram, the teeth of both gears move upwards. This means that the ...

Macs have always been favorites of case modders, with projects ranging from turning a Mac Plus into an ... an aesthetic that usually means gluing gears to wood. [Valeriy] and [Cyrill] are bucking ...