Richard Mille - RM 031 - High Performance Chronometer

CALIBRE RM031 Manual winding movement with hours, minutes, small seconds, and function indicator. Limited edition of 10 pieces While our technical-aesthetic credo is to open up fine watchmaking to the worlds of art, sport and lifestyle, our purpose here was to tackle the archetype of watchmaking as a fine art, with performance as an added bonus. This model proved our capacity to produce a quintessential specimen of watchmaking orthodoxy which guarantees extreme performance over the long term. The RM 031 is a timepiece that combines watchmaking tradition with pioneering concepts.

Despite its orthodox design, it is the result of a determined desire to create the world’s most consistent mechanical calibre. This is a highly ambitious goal that demands a variation of less than 30 seconds per month from the RM 031, which is far more difficult to obtain than more traditional daily accuracy rates allowing a variation in accuracy of 5 to 8 seconds per day. The caliber RM031 is equipped with an AP direct-impulse escapement. Developed by APR&P for Audemars Piguet , this escapement represents a subtle combination of a detent escapement and a Swiss anchor escapement.

The AP escapement provides an improved chronometric results thanks to the direct action of the escapement wheel on the balance wheel in contrast to a Swiss anchor escapement in which the anchor acts directly on the escape wheel. The AP escapement beats at 36000 vibrations per hour and is fitted with two Elinvar spirals that are set in opposite directions. It delivers a well improved efficiency. A dart is specifically designed for this kind of escapement, which prevents any overbanking.

To ensure the excellent transmission of the power released by the double barrels, all the wheels of the movement have been optimized by a special profile or the teeth with a pressure angle of 20°. This feature, inspired by automobile transmissions, produces long, continuous transfer of power along the entire going trains of the High Performance escapement. The baseplate and bridges are machined from ARCAP, a material used for the first time in watchmaking in the Richard Mille caliber RM002. ARCAP is renowned for its physical characteristics, which include corrosion-resistance and anti-magnetic properties.

These superlative technical characteristics are combined with outstanding hand-finishing operations. Many hours of work are required to produce each of the movement’s components, perfectly exemplified by the microblasted baseplate and escapement-holder, the polished, microblasted, beveled and circular-grained wheels, the burnished sections, or the soft-polished escapement bridges. The round case (50 mm x 13. 90 mm) is made in four parts according to an exceptionally complex design, and has been chamfered, polished and brushed for a unique finish. Lastly, in a perfect demonstration of the attention devoted to every detail, the lugs are carefully designed to extend the lines of the case while following the curve of the strap. Top view Right view Back view Left view.