[johneh]

Legendary service intervals? Please, if there was an eye roll emoji I'd use it here.

@TheVTCGuy - the mainspring does in fact power the movement of the hands on a spring drive. The explanation is fairly complicated, but I am sure you will get it. First off, instead of a balance wheel, the SD movement has a glide wheel. When you first start up a SD watch the glide wheel will spin freely, causing the second hand to move way too fast which fires up the electricity required to power a circuit and the quartz oscillator. The quartz oscillator acts as a reference point and tells an electromagnetic brake to slow down the glide wheel. The way a spring drive works is that it's always trying to go fast, and the brake slows it down.

In easy to understand terms: The mainspring powers the hands, which power a tiny generator inside the watch, which controls a little computer that tells the watch to go slower.