The young and disruptive brand BA111OD is proudly launching its first manufacture movement with its CHPTR_Δ (pronounced Chapter Delta) watch. Developed and produced with the help of Olivier Mory, the renowned watchmaker from La Chaux-de-Fonds, CHPTR_Δ brings an unprecedented reading of time through a duality between the circular time of the minutes and the hypocycloidal time of the hours. This asymmetrical reading of time, which slows down and starts again, like a choreography, is part of another temporality, symbolizing the carousel of life.
How does the BA111OD CHPTR_Δ watch work, exactly? Rather than simply rotating an hour hand around a central axis, the movement was designed to “roll” a satellite hour wheel around a fixed central 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. In this new chapter for BA1110D, 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 triangular.