SJX Watches
Insight: Regulating a Mechanical Watch Movement
A mechanical watch is not always spot on; less-than-perfect timekeeping can happen, often due to an unruly oscillator. The solution is direct adjustments to the hairspring and balance assembly, either slowing down or speeding up the oscillator, a practice known as regulation. Watchmakers have devised multiple innovations to achieve this, including the free-sprung balance, exemplified by the Gyromax of Patek Philippe and Microstella of Rolex. While a simple concept in principle, the mechanics and practice of regulation are nuanced. Here we’ll delve into the theory of regulation and the primary regulating systems: the curb-pin regulator and the free-sprung (or variable inertia) balance. The Lange L043.4 with a screwed balance inspired by pocket watches Basic concepts In order to better understand watch regulation, we need to first cover some of the basic physics behind the watch oscillator: The component responsible for the running rate of a movement is its regulating organ. The regulating organ is made up of a hairspring paired to a balance, which together are also known as a harmonic oscillator. The natural oscillation period is the time it takes the balance to make a full swing, back and forth. The period is made up of two vibrations, one for each direction of the balance motion, with the escapement being unlocked at each vibration. Notably, the natural period of a balance wheel is intrinsic to itself and does not depend on the escapement type or the going train ratio. ...