The three-axis tourbillon is one of the most complex watch complications in the world. Originally based on a design by watchmaker Abraham-Louis Breguet, this type of tourbillon – literally “whirlwind” – rotates the balance wheel of a watch in order to ensure that gravity doesn’t adversely affect any part of the watch. It’s a clever, complex, and essentially useless complication in an era of atomic clocks and nano materials but darn if it isn’t cool-looking.
As you can see, the main component is the balance wheel which flips back and forth to drive the watch. The balance wheel is contained inside a sort of spike-shaped cage that rotates on multiple axes. The balance wheel controls the speed of the spin and often these devices are used as second hands on more complex – and more expensive – tourbillon watches. Tourbillons were originally intended to increase watch accuracy when they were riding in a vest pocket, the thinking being that gravity would pull down a watch’s balance wheel differently when it was vertical as compared to being horizontal. In this case, the wheel takes into account all possible positions leading to a delightful bit of horological overkill.