Richard Mille RM025 Tourbillon Diver's Chronograph
It has finally arrived. The one everyone has been waiting for. After creating watches for the rigors of land, the G-forces of the racetrack as well as the open seas, now the depths of the ocean have been scrutinized by Richard Mille, with his introduction of the RM 025.
This new creation is a watch suitable for the world of diving and the demands of the deep sea. It is unlike any other Richard Mille creation in terms not only of its exterior appearance but also its ability to deal with one of the harshest environments on the Earth without difficulty. Visually the watch breaks with the iconic Richard Mille case, yet this is a change born directly from technical necessity. Water resistance of this kind, 30 atmospheres (300 meters) following ISO 6425 diver's watch norms, is only possible at these depths with a round case shape. However, look closely and what at first glance seems deceptively simple is much more complex...
The unique tripartite case design uses torque screws that can be individually and precisely tensioned with high accuracy around the exterior circumference of the case, thus guaranteeing a waterproof closure of evenly distributed pressure along the case edge, essential for a long term seal. This is complemented by the additional integration of the lugs into the case's torque screw system, as well as the screwed crown construction and a new design of watertight pushers. The bezel is also unlike any other. It is constructed of three layers, connected with 24 screws, turning unidirectionally following ISO 6425 norms in order to avoid timing miscalculations. In addition, the entire bezel system is screwed to the watchcase making it absolutely stable as well as impossible to inadvertently dislocate or loosen. This unique use of screws allows for perfect adjustment since the bezel is not tensioned into position. For clearer visibility under murky conditions, starting at 12 o'clock, the five-minute markers of the first quarter are highlighted red.
All this attention to detail is just the icing on the cake however; within ticks the caliber RM 025, a carbon nanofiber tourbillon chronograph based upon the famed caliber RM 008, one of the major and uniquely new chronograph designs of the 21st century. The RM caliber 025 unites 2 extremes: the complication of a tourbillon with the notorious complexities of a chronograph movement.
The engineering of this new timepiece took more than five years of development since the designers began with a blank piece of paper, leaving all preconceived notions behind. This led to a number of new impulses, such as creating and manufacturing a number of parts such as the column wheel and levers in titanium in order to reduce inertia and lower energy consumption circa 50%. This greatly reduces friction on the spindle and eliminates the jumps and shocks of the chronograph hand during stopping
and starting, adding to the watch's precision. The production and assembly of the RM 025 Tourbillon Diver's watch takes many months, with only a select number of watchmakers able to cope with its complex assembly and testing. For this reason, it is only possible to produce a highly limited number of these watches per year.
Available in 18-carat red or white gold and titanium, all models are fitted with 18-carat red gold lugs with a screwed, Richard Mille designed rubber diver's strap.
CALIBER RM 025: Manual winding tourbillon movement with hours, minutes,
chronograph, power reserve, torque indicator, function indicator.
Dimensions: Diameter 50.70 mm x 19.20 mm (thickest area).
Circa 70 hours (numerical indications to the left of the barrel).
CHRONOGRAPH (Column wheel in titanium)
The modern architecture of this movement has allowed for the consistent and rational arrangement of its constituent parts, avoiding unnecessary superimpositions and permitting the best possible use of the functions with technical solutions. For example, research was conducted into the geometrical design of the column wheel that controls the different levers to ensure the perfect, long-term simultaneity of the functions, a feature that is essential for a high performance chronometer.
This design was implemented in order to achieve a high degree of continuity of the settings and an unfailing repeatability of the functions.
Operation: The user can start or stop the chronograph function via the pusher located on the lower left at 8 o'clock. The hands are reset by pressing another pusher located on the upper left at 10 o'clock.
300 METER WATER RESISTANT CASE
The watch is water resistant to 30 atmospheres (300 meters) following ISO 6425 diver's watch norms. This is achieved with a unique tripartite case design using torque screws that can be individually and precisely tensioned with high accuracy around the exterior circumference of the case, thus guaranteeing a waterproof closure of evenly distributed pressure along the case edge, essential for a long term seal. This is complemented by the additional integration of the lugs into the case's torque screw system, as well as the screwed crown construction and a new design of watertight pushers. The lugs of all versions (18-carat red and white gold or titanium) are in 18-carat red gold, with screws
for the attachment of the rubber diving strap.
Built up of three layers connected with 24 screws, turning unidirectionally following ISO 6425 norms to avoid timing miscalculations. The use of an additional screwed system attaching the bezel to the watchcase makes it absolutely stable as well as impossible to inadvertently dislocate or loosen. In addition, the use of screws allow for perfect adjustment since the bezel is not tensioned into position. For clearer visibility under murky conditions, starting at 12 o'clock, the five-minute markers of the first quarter are highlighted red.
Supplies information about the tension of the mainspring, and allows the optimalization of the chronometer function of the movement. Below 53 dNmm, the spring is considered to be too slack, while above 65 dNmm, the excessive spring tension can adversely affect the mechanism's operation, or else actually endanger it. These indications appear on the numerical zone to the right of the barrel.
BALANCE WHEEL WITH VARIABLE INERTIA
This type of balance wheel, which represents the ultimate in innovation, guarantees greater reliability when subjected to shock and also during assembly and dismantling of the movement, thus achieving better chronometric results over time. The index is eliminated, thereby allowing a more precise and repeatable adjustment.
FAST ROTATING BARREL (6 hours per revolution instead of 7,5)
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.
BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits an appreciable winding gain (circa 20 %), especially during the start of winding. It also aids in the even distribution of the mainspring's internal tension.
In order to improve performance, lengthy research was carried out to determine a special curve of the hairspring, aimed at reducing the shifting of the centre of gravity during functioning.
New in-line escapement design, aimed at reducing friction.
MODULAR TIME SETTING MECHANISM FITTED AGAINST THE CASE BACK
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 bottom plate in the event of a possible defect or during maintenance;
- The mounting and dismantling of this module from the back will not require the removal of the hands and the dial.
In a manner similar to a car's gearbox, a push-button located at the center of the crown allows one to select the winding, neutral and hand setting functions with a simple push. A hand at 4 o'clock displays the selected function: W (Winding) - N (Neutral) - H (Hands)
CLOSURE OF THE BARREL COVER USING EXCENTRIC SCREWS
This development is again part of the intention to make servicing easy, logical, and of a very high mechanical standard.
WHEEL BASED TIME SETTING SYSTEM (back of the movement)
Provides smooth time setting functions through the elimination of engaging friction
by replacing it with rolling friction.
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.
TOOTH SYSTEM OF BARREL AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The wheel with a central developing profile and a pressure angle of 20° promotes rolling movement more effectively, compensates differences between centers, ensures excellent torque transmission and a distinct improvement in performance.
- Center bridge in titanium
- Movement diameter: 38.95 mm
- Thickness: 8.12 mm
- Tourbillon diameter: 12.30 mm
- Diameter of the balance wheel: 10.00 mm
- Number of jewels: 38
- Balance wheel: in GLUCYDUR, 2 arms, 20 adjusting screws.
- Moment of inertia: 10 mg cm2, lever angle 53°
- Frequency: 21,600 vph (3 Hz)
- Balance spring: ELINVAR by NIVAROX
- Shock resistance: KIF ELASTOR KE 160 B28
- Barrel shaft: in chronifer without nickel (DIN x 46 Cr 13 + S), which has the
following characteristics: non-oxidizable - antimagnetic - hardened
- Anglage and polishing by hand
- Locking sections hand polished
- Sapphire blasted milled sections
- Lapped and polished contact points
- Burnished pivots
- Sapphire blasted surfaces
- Anglage and polishing by hand
- Concave chamfering with a diamond tool
- Circular finished faces
- Gilded (before cutting the teeth)
- Minimum correction applied to the wheels in order to preserve geometry and performance
Source: Richard Mille