RM 51-02
SPIRALLING VORTEX
This fine jewellery tourbillon takes its cues from the swirling forms of a twisting spiral, a shape expressed in many organic forms around us in the natural environment and an expression of what is known as ‘the golden number’ or harmonic proportion.
The spray of diamonds emanating outwards in 14 rays from the tourbillon. Here, the design is symbolic of a fireworks display erupting out of the tourbillon cage.
CALIBRE RM51-02
Manual winding tourbillon movement
Hours, minutes and power-reserve indicator
Power reserve: Circa 48 hours (± 10%)
Dimensions: 47.95 x 39.70 x 12.60 mm
DIAL
Each spiral ray is perfectly set with a single row of diamonds. The spray of diamonds emanating outwards in 14 rays from the tourbillon escapement at 6 o’clock can also be associated with the spiralling vortex one perceives in the Milky Way, or as an allusion to the whirlwind or tornado, or the spiral patterns of organic growth exhibited by certain sea creatures, plants, trees and animals.
BLACK ONYX BASEPLATE
Onyx is a variety of cryptocrystalline quartz chalcedony composed of silica dioxide (SiO2). The variety with rectilinear black and white parallel stripes is part of the agate family, whereas the fully black type is known as black onyx.
A gemstone thought to deflect and channel harmful energy towards the Earth, it provides stability. For this reason, black onyx is considered a stone of protection against negative thoughts, as well being the stone of equilibrium and inspiration.
MOVEMENT CHARACTERISTICS
Movement dimensions: 30.20 x 28.60 mm
Thickness: 4.97 mm
Tourbillon diameter: 12.30 mm
Balance wheel diameter: 9.12 mm
Number of jewels: 21, set in white gold chatons
Balance wheel: Glucydur®, 2 arms and 4 setting screws, moment of inertia 10 mg•cm2, angle of lift 53º
Frequency: 21,600 vph (3 Hz)
Balance spring: elinvar by Nivarox®
Shock protection: KIF Elastor KE 160 B28
Barrel shaft: nickel-free Chronifer® (DIN x 46 Cr 13 + S) with the following characteristics: stainless – antimagnetic - suitable for tempering.
CASE
This tripartite tonneau-shaped case is fully curved, which makes the watch ergonomic and comfortable, but is time consuming to produce and requires a high level of quality control.
The bezel and the caseback have to be perfectly assembled with the case middle to prevent damage to the sapphire crystals. Developing the requisite manufacturing specifications demanded an entire year of research and development.
The case is set with white diamonds, and black sapphires have been added to accentuate case details.
BRIDGES IN GRADE 5 TITANIUM
These components are crafted in grade 5 titanium with black PVD treatment, conferring great rigidity on the whole assembly, as well as the precise surface flatness essential for perfect functioning of the gear train.
TORQUE-LIMITING CROWN
This security system prevents accidental overwinding of the watch, which can cause damage to the winding stem or put extreme pressure on the barrel spring.
As a final flourish and with an eye for detail typical of Richard Mille’s fastidious approach, the crown has also been set with 3 rows of diamonds to complete the brilliant richness of this shimmering piece.
Finishing
Movement
• Anglage and polishing by hand (excluding onyx and black PVD-treated parts)
• Hand-polished locking sections
• Sapphire-blasted milled sections
• Lapped and polished contact points
• Burnished pivots (excluding Onyx)
Steel parts
• Sapphire-blasted surfaces
• Satin-finished surfaces
• Anglage and polishing by hand
• Burnished sections
Wheels
• Concave chamfering with a diamond tool
• Circular-finished faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance.
Other features
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits a profitable winding gain (circa 20%), especially during the winding start. It is also helpful in the even distribution of the mainspring’s internal tension.
WINDING-BARREL TEETH AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The central involute profile of the winding barrel teeth and pinion provides an optimal pressure angle of 20°. This promotes effective rotary motion and compensates for possible variations in the engagement of the going train thus ensuring excellent torque transmission with a distinct improvement in performance.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
This permits better control of torque applied to the screws during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.