RM 50-02
A SYNERGETIC APPROACH
Airbus is a name that requires no introduction as a world leader in the application of novel approaches to aeronautical design, in particular those aircraft created for personal clients by its ultra-luxury subsidiary, Airbus Corporate Jets, or ACJ. It was thus only natural that Richard Mille and ACJ joined forces to realise this horological masterpiece inspired by their respective worlds.
RM 50-02 TOURBILLON ACJ
CALIBRE RM50-02
Manual winding tourbillon movement with hours, minutes, split-seconds chronograph with running seconds, 30-minute totaliser and power-reserve, torque and function indicators.
Limited edition of 30 pieces
POWER RESERVE
Circa 70 hours (± 10%) without the chronograph running. Actual power reserve results will depend on the period of time the chronograph is utilised.
SKELETONISED GRADE 5 TITANIUM BASEPLATE AND BRIDGES
The RM 50-02 makes use of advanced, open-work design elements in design of its bridges and baseplate made of grade 5 titanium, along with an extensive skeletonisation in every possible area, to achieve significant weight reduction. A number of parts within the movement are coated with a distinctive aeronautical coating normally used to protect engine and chassis parts from corrosion and environmental conditions.
The baseplate is finished in grade 5 titanium, a biocompatible, highly corrosion-resistant and remarkably rigid alloy, which enables the gear train to function effortlessly.
The alloy is 90% grade 5 titanium, 6% aluminium and 4% vanadium. This combination further enhances the material’s mechanical properties, which explains its frequent use in the aerospace, aeronautics and automotive industries. The baseplate of the Calibre RM50-02 has been improved to achieve an extreme weight/resistance ratio. The skeletonised baseplate and bridges were subjected to intensive and complete validation tests to optimise their resistance capacities.
To give more depth to the calibre, some bridges are made of stainless steel and given a golden appearance by treatment with aircraft coatings.
SPLIT-SECONDS CHRONOGRAPH WITH IMPROVED PERFORMANCE
The modern architecture of this movement allows a coherent and rational arrangement of each constituent part, avoiding unnecessary complexity and permitting the best possible use of the functions thanks to technical solutions.
For example, research was conducted into the geometric design of the column wheels that control the different levers, in order to ensure the perfect, long-term, stable and simultaneous functioning of the chronograph mechanism, a feature that is essential for a high-performance chronograph.
Furthermore, the development of a new generation of split-seconds components has lowered the energy consumption of this function as much as 50% by reducing friction on the spindle. Like the prevention of jumping in the chronograph seconds hand, this was achieved by research focused on the working of the split-seconds arms.
FUNCTION INDICATOR
In a manner similar to a car’s gearbox, the function indicator makes it possible to identify the winding, neutral and hand-setting positions as the crown is pulled out. The active position is indicated via a hand at 4 o’clock: W (Winding) – N (Neutral) – H (Hands).
TORQUE INDICATOR
This indicator supplies information about mainspring’s tension, thus permitting optimisation of the movement’s chronometric functioning. Below 53 Nmm, the spring is considered too slack, while above 65 Nmm, excess tension in the spring can adversely affect the mechanism’s operation, or actually endanger it.
POWER-RESERVE INDICATOR
Located on a scale at 11 o’clock, the power-reserve indicator shows the number of hours of energy left in the mainspring before the watch must be wound again.
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 time.
MODULAR TIME-SETTING MECHANISM FITTED AGAINST THE CASEBACK
Provides the following advantages for longevity and maintenance:
• Since the component is mounted outside of the movement, the time-setting assembly can be changed without affecting the integrity of the baseplate in the event of a possible defect or during maintenance.
• The mounting and dismantling of this module from the back does not require the removal of the hands or dial.
MOVEMENT CHARACTERISTICS
Movement dimensions: 32.00 x 30.40 mm
Thickness: 7.87 mm
Tourbillon diameter: 12.30 mm
Balance wheel diameter: 10.00 mm
Number of jewels: 37
Balance wheel: Glucydur®,2 arms, 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 IN TITANIUM-ALUMINIUM
The highly distinctive and novel case shape, realised in a titanium-aluminium alloy (TiAl) with a secondary bezel in white ATZ ceramic was developed to mirror the outlines of an ACJ’s typical window shape, with a clearly visible, multi-layered hull structure surround. Titanium-aluminide, an intermetallic alloy, has characteristics that stand between metals and ceramics, with physical properties characteristic of a metal and mechanical properties resembling ceramic. It exhibits an extreme rigidity and is much lighter than classical titanium alloys. It is the same alloy used in the Airbus for its jet turbine blades.
TORQUE-LIMITING CROWN
The jet engine-inspired crown bears an engraved wave-patterned Airbus logo. The crown also incorporates a special security system to prevent accidental overwinding, which could cause damage to the winding stem or place extreme pressure on the barrel spring.
TORQ-SET® SCREWS
Torq-set® screws utilise a waved slot pattern where each arm of the slot is also offset from its neighbour.
These types of screws are used in aerospace applications where the applied torque must be exactingly executed, and for the security they offer against tampering. This configuration provides greater strength within the screw than a cruciform design, with an excellent transfer of torque.
Finishing
Movement
• Hand-polished bevelling
• Hand-polished locking sections
• Microblasted milled sections
• Lapped and polished contact points
• Burnished pivots
Steel parts
• Wire-drawn and microblasted surfaces
• Hand-polished bevelling
Wheels
• Concave chamfering with a diamond tool
• Circular-decorated faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance
Other features
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.
WINDING-BARREL TEETH AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The central involute profile of the winding barrel-teeth provides an optimal pressure angle of 20° which promotes effective rotary motion and compensates for possible variations in the operation of the going train. This, in turn, ensures excellent torque transmission and a distinct improvement in performance.
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits an appreciable winding gain (circa 20%), especially during the start of winding. It is also helpful in evenly distributing the mainspring’s internal tension.