A NATURAL ADDITION
RM 57-03 TOURBILLON SAPPHIRE DRAGON
Manual winding tourbillon movement with hours and minutes.
Circa 42 hours (± 10%).
The manufacture of these components in grade 5 titanium allows the whole assembly to be given great rigidity, as well as precise surface flatness which is essential for the perfect functioning of the gear train.
The skeletonised baseplate and the bridges have been subjected to intensive and complete validation tests to optimise their resistance capacities.
DRAGON ENTWINED IN THE MOVEMENT
The dragon, a mythical animal arising from an ancestral imaginary world and indissociable from Oriental culture, has multiple meanings. Here, it is a symbol of perseverance and success as well as of the power and strength that make it a master of the elements. This notion of robustness and reassuring solidity, visible in the bearing of the dragon that firmly encircles the manually-wound tourbillon calibre, dictated the creative process followed by the engravers at Olivier Vaucher—a major name in engraving in Geneva—working in collaboration with the Richard Mille movement and exterior engineers on this complex endeavour.
As a fantastical creature moving through the water, the dragon harmoniously encapsulates the Yin of sapphire, associated with the liquid element, and the Yang of gold, which carries the opposing heat and positive connotations of the Sun.
Sapphire has a special place at Richard Mille, which uses this material to craft the most complex cases and movement components. Its transparency, resulting from the purity of the aluminium oxide crystals (Al2O3), and its hardness of 1,800 Vickers make it an exciting substance to work with. While Richard Mille sapphire cases are generally ground, on this occasion the technique was set aside in favour of laser micro-cutting, performed using a specific machine to this project. This was done to obtain the piece’s extremely precise details and curves while avoiding undesirable physical and chemical reactions. It was thanks to countless hours of R&D and Computer-assisted design (CAD) programming that the construction was rendered reliable and weak points eliminated.
To engrave the dragon, Olivier Vaucher and his teams developed new hand-polishing and finishing techniques to enhance the natural transparency of the sapphire. The head and feet in carved red gold also serve to accentuate the crystalline texture of the sapphire and the volume of the subject. The minute details of the scales were the result of a long and delicate process of painting with gold, while applying these to the dragon’s tongue and eyes—giving it a determined look—added a final artistic dimension to the piece.
FAST-ROTATING BARREL (6 hours per revolution instead of 7.5 hours)
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.
FREE-SPRUNG BALANCE WITH VARIABLE INERTIA
The free-sprung balance offers better reliability in the event of shocks, movement assembly or disassembly, and also guarantees better chronometric results over an extended period of time.
Movement dimensions: 32.10 x 30.30 mm
Thickness: 5.27 mm
Tourbillon diameter: 12.40 mm
Balance wheel diameter: 9.12 mm
Balance wheel: Glucydur®, 2 arms and 4 setting screws, moment of inertia 11.50 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
The three-part tonneau-shaped case is highly curved, which means the watch is comfortable to wear but time consuming in terms of production and quality control.
The ergonomic and visually distinctive curvature of the case is typical of all Richard Mille timepieces, requiring absolute precision and a total lack of tension in the metal. These requirements for the case design are based on a year’s worth of research and development.
The tripartite case is water resistant to 50 metres, ensured by 2 Nitrile O-ring seals. The case is assembled with 20 spline screws in grade 5 titanium and abrasion-resistant washers in 316L stainless steel.
- Hand-polished bevelling
- Microblasted milled sections
- Drawn or polished outer faces
- Microblasted surfaces
- Satin-brushed surfaces
- Hand-polished bevelling
- Hand-drawn finishing on the upper surfaces
- Matte strokes on the underside
- Lengthwise hand-drawn strokes on the sides
- Polished sinks
- Concave chamfering with a diamond tool
- Circular-smoothed faces
- Rhodium-plating (before cutting the teeth)
- Minimal corrections applied to the wheels in order to preserve geometry and performance
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits a profitable winding gain (circa 20%) especially during the winding start. It is also helpful in ensuring an 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 the torque applied to the screws during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.