First Manufacture movement for BA111OD

The Neuchâtel-based brand launched this spring its first Manufacture movement offering unprecedented reading of time.

CHPTR_Δ (pronounced Chapter Delta) brings a duality between the circular time of the minutes and the hypocycloidal time of the hours, enclosed in a triangle, to the foreground on the dial. This asymmetrical reading of time, which slows down and starts again, like a choreography, is part of another temporality, symbolising the carousel of life.

While the minutes hand travels around the dial in the usual way, the hour is indicated by a small dot following a hypocycloidal path within a triangle, creating a non-linear experience of time. “I particularly appreciate this aspect. Besides being mesmerising, it’s the symbolic aspect of life that fascinates me. Like those precious moments that last or slip away... the hours dot slows down and then speeds up again in a movement that appears irregular yet is perfectly calibrated and precise,” says brand founder Thomas Baillod.

This project, initially imagined by the designer Diego Böttger-Zevallos, turned out to be complex to realise. To ensure its technical development and production, Thomas Baillod once again called upon the watchmaker Olivier Mory, who was already behind the BA111OD Chapter 4 Tourbillon. Virtually nothing but the transcendent beauty of mathematics could have achieved a triangle while exclusively using things that rotate in circles! And it is a discreet tribute to the several centuries-old use of the cycloid in watchmaking. Galileo, Newton, Huygens, Euler, Cantor or Roberval, to name but a handful, have all worked on the amazing properties of these curves”, says Olivier Mory.

Rather than simply rotating a hand around a central axis, the movement was designed to “roll” a satellite hour wheel around a fixed central hours wheel. When a wheel is rotated around another wheel, the trajectory described by any point on this satellite wheel is a cycloid. There are several types of cycloids, some of which have particular trajectories, depending on the size ratio between the fixed wheel and the satellite wheel, as well as whether the satellite wheel rotates inside or outside the fixed wheel.

At the heart of the timepiece, the chosen cycloid is a deltoid (with a ratio of 1/3), and as a result, the trajectory described by the tip of the hour hand is... a triangle, a particular shape highly appreciated by BA1110D. With its three legs, this raised geometrical shape represents direction and determination. It symbolises stability and balance.

June 01, 2023