- Jul 17, 2014
Jul 28, 2020
Watchfinder & Co. presents:
Some dive watches can withstand enormous depths, others have lume brighter than the sun and a few even throw a couple of other complications into the mix. Not so the RM 028 from Richard Mille. It does none of those things. In fact, it’s pretty straightforward. So why is it one of the craziest dive watches ever made?
Richard Mille RM 028
DEVELOPMENT GUIDED BY EXTREME SUBMARINE CONDITIONS
We created the RM 025 because we wanted to tackle the circle in all its roundness, and its creation supplied us with the technical foundation for developing the automatic movement of the RM 028. Cased in a slightly smaller diameter of 47 mm, this creation has all the hallmarks of its uncompromising character.
Following the direction set out by the first diver’s watch created by Richard Mille, the RM 025, the RM 028 uses a number of key elements that demarcate the theme of diving within the collection. Its exceptional tripartite case with a unidirectional bezel and water resistance to 300 metres follows ISO diver’s watch norm 6425, creating a perfect environment to house the skeletonised movement with variable rotor geometry, a Richard Mille exclusive.
RM 028 AUTOMATIC DIVER'S WATCH
Automatic winding movement with hours, minutes, central seconds, date and variable-geometry rotor.
Circa 55 hours (± 10%).
BASEPLATE AND BRIDGES MADE OF GRADE 5 TITANIUM
Production of these components in grade 5 titanium with black PVD or Titalyt® coating confers great rigidity to the entire assembly, as well as precise the surface flatness essential for perfect functioning of the gear train.
The baseplate and bridges were subjected to separate and extensive validation tests to ensure it met optimal strength requirements.
Semi-instantaneous, the calendar disc of sapphire crystal is treated with non-reflective coating on both sides.
The Richard Mille RM 028 uses variable geometry to optimise the rotor’s winding motion.
• Arm in grade 5 titanium
• High palladium content 18K white gold weight segments
• Weight segment with 6 possible positions adjusted by screws in grade 5 titanium
• Ceramic ball bearings
• Unidirectional; anti-clockwise winding direction
This exclusive Richard Mille design makes it possible to effectively adapt rewinding of the mainspring to the user’s activity level, in sporting or non-sporting environments. By adjusting the six-position rib, the rotor’s inertia is modified to either speed up the winding process in the case of leisurely arm movements, or to slow it down during sporting activities.
Movement dimensions: 30.25 x 28.45 mm
Thickness: 4.14 mm
Number of jewels: 32
Barrel arbour: AP 20 steel
Balance: Glucydur®, 4 arms, moment of inertia 4.8 mg•cm2, angle of lift 53°
Frequency: 28,800 vph (4 Hz)
Balance spring: elinvar by Nivarox®
Shock protection: INCABLOC 908.22.211.100 (transparent)
Escapement wheel jewels: Rubifix (transparent)
Three-position stem: manual winding, date adjustment, time setting
The watch is water resistant to 30 atmospheres (300 metres) per ISO 6425 diver’s watch norms.
This is achieved with a unique, curved, tripartite case design using torque screws that can be individually and precisely tensioned with high accuracy around the exterior circumference of the case. This is complemented by a screw-lock crown construction.
This component is constructed of three layers connected with 22 screws, turning unidirectionally per 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 makes perfect adjustment possible, 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 in red.
• Baseplate and bridges in hand-ground, wet-sandblasted grade 5 titanium, black PVD or Titalyt® treated
• Burnished pivots
• Diamond-polished sinks on the bridge side
• Pinions with undercuts
• Sapphire-blasted surfaces
• Anglage and polishing by hand
• Screw slot and screws bevelled and polished with rounded and polished tip
• Sandblasted and rhodium-plated, bevelled wheels (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance