How Does an Automatic Mechanical Watch Wind Itself?

　　An automatic mechanical watch builds upon the base movement of a manual mechanical watch by adding an automatic winding mechanism. This harnesses the kinetic energy from the wearer's arm movements and stores it in the mainspring, removing the daily chore of manual winding. Simply put: automatic mechanical watch = manual mechanical watch + automatic mechanism.

　　The automatic system is the only mechanism within a watch movement capable of replenishing energy; all other complication modules consume energy. Typically, an automatic section contains 30-40 components, up to 40-50 in more complex designs, including the oscillating weight, bearings, reversing wheel, automatic reduction gear, automatic bridge, and screws.

　　Operating principle of the automatic mechanism

　　Wrist movement causes the off-centre oscillating weight to swing back and forth. Via the reversing mechanism, it drives the automatic gear train to ensure the ratchet wheel turns unidirectionally in the winding direction, continuously tensioning the mainspring. The reversing mechanism is a specialised structure that ensures the mainspring is wound regardless of which direction the oscillating weight rotates.

　　The automatic winding process sequence

　　Kinetic energy from the arm → potential energy → oscillating weight → reversing mechanism → automatic gear train → mainspring barrel system (base movement), winding the mainspring.

　　Automatic mechanical watches are classified into two types based on the rotation angle of the oscillating weight: fully automatic and semi-automatic.

　　Fully automatic: The oscillating weight can rotate in a 360° circle, winding the mainspring in both directions.

　　Semi-automatic: The oscillating weight cannot rotate in a full circle and can only rotate within a certain angle, which is around 270°, but it can wind the mainspring in both directions.

　　N Factory Watchesautomatic mechanical watches are all fully automatic mechanical watches.

Audemars Piguet Royal Oak Offshore 26470ST.OO.A104CR.01, 1:1 craftsmanship, custom 3126 mechanical movement

　　Please note: Automatic watches are not perpetual motion timepieces.

　　A fully wound automatic watch from N Factory usually has a power reserve of 38 hours. If you do not wear it over the weekend, or if your physical activity is insufficient, it may cause the watch to lose accuracy or stop running.

　　Therefore, if it has not been worn for a while, please manually wind it at least 20 turns before wearing it again, and then wear it normally every day.

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