RM 07-02

Automatic Winding Sapphire

Skeletonised automatic-winding in-house movement

Hours, minutes and variable-geometry rotor

Baseplate, bridges and variable geometry rotor

Power reserve : around 50 hours (± 10%).

Dimensions: 32.90 x 46.75 x 14.35 mm

Crafted from sections of colored sapphire taken from a single block, this case is extremely difficult to machine.

Observing the manufacturing process of a sapphire case highlights the challenge its creation entails, from both an engineering and a technical standpoint. There is no room for even a single cutting error.

The case requires almost forty days of machining and finishing to meet the uncompromising specifications laid out by Richard Mille. Numerous tests then follow to verify that the brand’s resistance and comfort requirements have been met.

Movement dimensions: 29.90 x 22.00 mm

Thickness: 5.05 mm

Number of jewels: 25

Balance: CuBe, 4 arms, 4 setting screws, moment of inertia 7.5 mg•cm 2, angle of lift 50°

Frequency: 28,800 vph (4 Hz)

Balance spring: AK3

Shock protection: INCABLOC 908.22.211.100 (transparent)

Escapement wheel jewels: Rubifix (transparent)

Gold had already lost its pride of place in the gemset ceramic and Carbon TPT® watches. With the gemset sapphire, the brand expresses its new approach to diamonds through coloured sapphire.

Setting each element is a real engineering feat requiring a laser operating to the nearest micrometre. Prongs in red or grey hand-polished gold, made separately, are then inserted, creating multiple settings to hold a delicate row of diamonds.

The baseplate and the bridges are machined from 18K white gold, which is microblasted and bevelled by hand. The baseplate is decorated and set with hundreds of diamonds, an aesthetic feat achieved thanks to the long and delicate work of the gem setter.

The skeletonised baseplate and bridges were subjected to separate and extensive validation tests to optimise their resistance capacities.

The rotor allows to be set according to the owner’s activity level. The setting is modified by adjusting two weights that can be adjusted and fixed in place by spline screws. The inertia of the movement is increased when the two weights are closer to each other; the barrel then rewinds more quickly. If the weights are positioned at the extremities of the rotor, the inertia is decreased and the barrel winds more slowly.

Specifications

• • Heavy external outside edge and heavy edge ring in gold

• • Weight segment in heavy metal

• • Automatic OneWay® ceramic winding system with ball bearings

• • Bidirectional winding system

• • Hand-polished anglage

• • Microblasted milled sections

• • Hand-polished sinks

• • Burnished sections

• • Satin-finished surfaces

• • Hand-polished anglage

• • Hand-polished sinks

• • Burnished sections

• • Concave chamfering with a diamond tool

• • Diamond-polished angles

• • Circular-finished faces

• • Rhodium plating (before cutting the teeth)

This type of barrel provides the following advantages:

The phenomenon of periodic internal mainspring adhesion is significantly diminished, thereby increasing performance, Provision of an excellent mainspring delta curve with an ideal power reserve/performance and regularity ratio.

The entire going train of the watch, the primary transmitter of power to the movement, utilises a special profile for the wheel teeth with a 20˚ pressure angle. This system equalises any discrepancies that might arise between the centres of each wheel, for instance during thermal changes and normal use, and promotes an excellent transmission of torque to the balance wheel, thus supporting superior chronometric results.

This type of balance wheel represents the ultimate in innovation. It guarantees greater reliability when subjected to shocks or during movement assembly or disassembly, hence better chronometric results over time. The regulator index is eliminated, and a more accurate and repeatable calibration is possible thanks to 4 small, adjustable weights located directly on the balance.