Unveiled at SIHH 2014, the RM 61-01 YOHAN BLAKE houses a manual winding skeletonised movement. The materials used in the construction of this timepiece are highly innovative, technologically advanced and both case and movement are well executed and finished.
Special features of the Movement
Baseplate and Bridges in Grade 5 Titanium: The manufacturing of these components in grade 5 titanium with black PVD coating for the baseplate and the bridges gives the whole assembly a great rigidity and achieves excellent surface flatness, essential to the perfect functioning of the gear train. The skeletonised baseplate and the bridges have been subjected to complete validation tests to optimise their stress resistance.
Free Sprung Balance with Variable Inertia: This type of balance wheel ensures greater reliability in the event of impact as well as during assembly and disassembly of the movement. This improves precision in the long term. There is no need for an index and it is possible to adjust the inertia more finely directly on the balance wheel via 4 small adjustable small weights.
Double Barrel System: The double barrel system helps improve torque stability over a longer period by reducing pressure and wear on the teeth, bearings and pivots, resulting in improved performance.
Spline Screws in Grade 5 Titanium for the Bridges: Their shape allows better control of the torque applied to these screws during assembly. The screws are thus perfectly resistant to manipulation during assembly and disassembly and are exposed to minimal wear and tear.
CALIBER RMUL2: manual winding skeletonised movement with hours, minutes and seconds; inspired by caliber RMUL1. Movement weight: circa 4.3 g. Power reserve: Circa 55 hours (±10%)
– Movement dimensions: 30.25 x 28.45 mm
– Thickness: 3.15 mm
– Jewels: 24
– Barrel arbor: in 20AP steel
– Balance wheel: Glucydur, 4 arms, moment of inertia 4.8 mg cm., angle of lift 53°
– Frequency: 28,800 vph (4 Hz)
– Balance spring: ELINVAR
– Shock protection: Incabloc 908.22.211.100 (transparent)
– Escapement wheel jewels: Rubifix (transparent)
– Stem with two positions: manual winding and time setting
TZP black ceramic was chosen for the RM 61-01 Yohan Blake’s bezel and caseback. This low-density material (6g/cm3) is highly scratch-resistant and has a low thermal conductivity coefficient. Constituted of 95% yttrium-stabilised zirconium, TZP has a pronounced grain that provides the perfect finish. A long and difficult machining and grinding process using diamond tools is necessary to create the complex forms of the bezel and caseback, which are given a final matt surface finish. Its drawn-out shape between 2 and 5 o’clock stops the torque-limiting crown from rubbing against the sprinter’s wrist.
The caseband is in NTPT® carbon, a material composed of multiple layers of parallel filaments obtained by dividing carbon fibers. These layers, with a maximum thickness of 30 microns, are impregnated with resin, and then woven on a special machine that modifies the direction of the weft by 45° between layers. Heated to 120°C at a pressure of 6 bars, the NTPT® is then ready for machining. When compared to composite materials, whose exceptional physical properties are already well known, NTPT® carbon improves breaking strains by 25% and the occurrence of micro-cracks by 200%.
The RM 61-01 case is water resistant to 50 meters. It is assembled with of 20 spline screws in grade 5 titanium and abrasion-resistant washers in 316L stainless steel. Dimensions: 50.23 x 42.70 x 15.84 mm.
Spline Screws in Grade 5 Titanium for the Case
Their shape allows better control of the torque applied to these screws during assembly. The screws are thus perfectly resistant to manipulation during assembly and disassembly and are exposed to minimal wear and tear.
In NTPT® carbon with Alcryn® collar
Upper flange in green anodized aluminum with hour index markers filled with approved luminescent material. Minutes flange in yellow varnished titanium.
Bezel side: in sapphire (1,800 Vickers) with anti-glare coating (both sides).
Thickness: 1.50 mm
Case back: in sapphire with anti-glare coating (both sides).
Thickness: at the center 1.20 mm and outer edges 1.95 mm.
– Baseplate wet sandblasted grade 5 titanium, PVD treated and hand-drawn after treatment
– Locking sections hand polished
– Burnished pivots
– Pinions with undercuts
– Sandblasted and rhodium-plating, beveled wheels (before cutting the teeth)
– Minimum corrections applied to the wheels in order to preserve geometry and performance
– Screw slot and screw beveled and polished with rounded and polished tip
– Straight line grain finish of the upper surface
– Lower surfaces microblasted
– Sink hand-polished
– Hand polished sinks