How do you hold three days of energy in a coin-sized space?

A mainspring thinner than a strand of hair is coiled inside an optimised barrel architecture that stores 1.8x the energy of a standard layout. Wound fully, it holds 72 hours; three days.

How does stored energy become readable time?

Wheel teeth are milled to a profile that carries 75% of the barrel's torque through to the escapement, stepping it down into hours, minutes and a continuous sweep seconds hand.

What stops the barrel emptying all at once?

The pallet fork locks and releases the escape wheel in measured steps, rationing the mainspring's torque into 21,600 vibrations every hour. This is what makes three days of energy last three days.

What sets the rhythm?

The oscillator - balance wheel and hairspring - swings at 3 Hz. Every other part of the calibre exists to keep this one oscillation honest; the rate is regulated by hand before the movement is signed off.

How do you stop metal wearing against metal?

22 synthetic ruby bearings are set at the highest-friction pivots and treated with epilame, which holds lubricant precisely where it is needed instead of letting it spread. Less friction lost is more of the barrel's 72 hours kept.

What holds 130+ components in alignment?

Solid brass, milled to a tolerance the eye cannot judge. A mechanical city on a canvas the size of a coin, and the reference every other part is set against.