RM 67-01
FLATNESS AS AN END
Like a car manufacturer, we consider the brand as being a general umbrella, which also targets certain ‘niches’. With this in mind, we particularly wanted to introduce a ‘lifestyle’ model with this extremely flat automatic watch based on the emblematic tonneau-shape casing.
The mechanical aspects of creating a thin automatic present their own set of difficulties, but one of the challenges is to pair this type of movement design with a sense of visual depth within the movement—a central tenet of the Richard Mille approach. The extreme skeletonisation seen in the RM 67-01 is one significant avenue to achieving this.
RM 67-01 Automatic Winding Extra Flat
CALIBRE CRMA6
Skeletonised automatic-winding movement with hours, minutes, date and function indicator.
POWER RESERVE
Around 50 hours (± 10%).
BASEPLATE AND BRIDGES IN GRADE 5 TITANIUM
Microblasted grade 5 titanium with grey electroplasma treatment lends great rigidity to the baseplate, as well as the precise surface flatness essential to perfect functioning of the gear train. Bridges are also in grade 5 titanium, microblasted and black electroplasma treated.
The skeletonised baseplate and bridges were subjected to separate and extensive validation tests to meet optimal strength requirements.
DATE DISPLAY
Semi-instantaneous, placed in a vertical aperture at 5 o’clock.
FUNCTION INDICATOR
In a manner similar to a car’s gearbox, the function indicator makes it possible to identify the winding, date-setting and hand-setting positions as the crown is pulled out. The active position is indicated via a hand at 2 o’clock displaying the following functions: W (Winding) – D (Date) – H (Hand Setting).
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. 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.
ROTOR IN PLATINUM
By using a platinum rotor with the OneWay® winding system and ceramic ball bearings, the barrel can be efficiently wound while maintaining the compact dimensions of this extra-flat, skeletonised movement.
MOVEMENT CHARACTERISTICS
Movement dimensions: 29.10 x 31.25 mm
Thickness: 3.60 mm
Number of jewels: 25
Balance: CuBe, 4 arms, 4 setting screws, moment of inertia 7.5 mg•cm2, angle of lift 50°
Frequency: 28,800 vph (4 Hz)
Balance spring: AK3
Shock protection: INCABLOC 908.22.211.100 (transparent)
CASE
The inimitable tonneau shape was first imagined in an extra-flat form for the RM 67-01 case, making it one of the sleekest tonneau-shaped Richard Mille timepieces there is. Its refined dimensions require more time to create than other similar cases in the collection, adding almost 6 hours of pure machining time, not counting the weeks of preliminary preparations, such as the 68 different stamping operations required for the bezel, caseband and back bezel.
The machine tooling process involves 8 days of adjusting the machines for the bezel, 5 days for the caseband, and 5 days for the back bezel. Prior to this process, developing a methodology for carrying out this series of operations took 145 hours, the drawings for the tools 130 hours, and implementation 180 hours. Each case represents more than 215 separate machining operations.
After machining is completed, the watch case undergoes brushing and polishing, all executed by hand, followed by assembly with sapphire glass and sealants and preliminary water-resistance testing, before being disassembled and undergoing a final quality control. Only then will the movement be mounted within its subtle lines. All of these operations represent an additional 8 hours of work.
DIAL
The mechanical aspects of creating a thin automatic poses their own set of difficulties, but one of the challenges is to combine this type of movement design with a sense of visual depth within the movement—a central tenet of the Richard Mille approach. The use of extreme skeletonisation in the RM 67-01 is one significant avenue explored here, however a new approach to the dial construction also carries the eyes from the edges of the three-layer bezel towards the hour and minute hands in the central area.
The numerals in the RM 67-01 are created from solid metal and mounted on two linked and rigid titanium rails attached directly to the movement.
Finishing
Movement
• Microblasted anglage
• Microblasted milled sections
• Microblasted sinks
• Grey and black electroplasma treatment for the baseplate, hand-drawn after treatment
Steel parts
• Lapped and polished ends
• Burnished pivots
• Post faces polished
• Hand-polished bevelling
• Hand-polished locking section
Wheels
• Concave chamfering with a diamond tool
• Diamond-polished angles
• Circular-finished 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 (5 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.
GEAR-TEETH PROFILE
The entire going train of the watch, the primary transmitter of power to the movement, utilises a special profile for the teeth of the wheels. The wheels use 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.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
This permits better control of torque applied to screws during assembly. These screws are therefore unaffected by physical manipulation during assembly or disassembly and age well.