RM 17-02
RM 17-02 Manual Winding Tourbillon
CALIBRE RM17-02
Manual winding tourbillon movement with hours, minutes, power-reserve and function indicators.
POWER RESERVE
Around 70 hours (± 10%).
BASEPLATE AND BRIDGES MADE OF GRADE 5 TITANIUM
The baseplate and the bridges are crafted of 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 increases the material’s mechanical properties, which explains its frequent use in the aerospace, aeronautics and automobile industries.
The skeletonised baseplate and the bridges were subjected to intensive and complete validation tests to optimise their resistance capacities.
FUNCTION INDICATOR
In a manner similar to a car’s gearbox, the function indicator identifies the winding, neutral and hand-setting positions as the crown is pulled out. A hand located at 4 o’clock indicates the current position.
POWER-RESERVE INDICATOR
Indicated by a scale located on a scale at 2 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 an extended period.
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.
MOVEMENT CHARACTERISTICS
Movement dimensions: 31.20 x 29.45 mm
Thickness: 4.65 mm
Tourbillon diameter: 12.30 mm
Balance wheel diameter: 10.00 mm
Number of jewels: 23, set in white gold chatons
Balance: Glucydur®, 2 arms, 4 setting screws, moment of inertia 10 mg•cm2, angle of lift 53°
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
The design and execution of the watch demonstrate a holistic approach to conception of the movement, case and dial. As a result, everything has been constructed according to extremely rigorous specifications, in the manner of the analytical engineering methods used in the design of Formula 1 racing cars, where the chassis and the engine are developed in complete harmony. For example, a casing ring is no longer used, and the movement is mounted on chassis mounting rubbers (ISO SW) fixed by grade 5 titanium screws. Features such as these are evidence of uncompromising workmanship.
The tripartite case is water resistant to 50 metres, ensured by 2 Nitrile O-ring seals. The case is assembled with 12 spline screws in grade 5 titanium and abrasion-resistant washers in 316L stainless steel.
TORQUE-LIMITING CROWN
This additional security system prevents accidental overwinding, which could cause damage to the winding stem or put excessive pressure on the barrel spring.
Finishing
Movement
• Anglage and polishing by hand
• Hand-polished locking sections
• Sapphire-blasted milled sections
• Lapped and polished contact points
• Burnished pivots
Steel parts
• Sapphire-blasted surfaces
• Anglage and polishing by hand
• Burnished sections
• Satin-finished surfaces
Wheels
• Concave chamfering with a diamond tool
• Circular-finished faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance.
Other features
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.
WINDING-BARREL TEETH AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The central involute profile of the winding-barrel teeth and pinion provides an optimal pressure angle of 20°. This promotes effective rotary motion and compensates for possible variations in the engagement of the going train, thus ensuring excellent torque transmission with a distinct improvement in performance.
CERAMIC ENDSTONE FOR THE TOURBILLON CAGE
This reflects a technical and long-term view towards reducing the phenomenon of wear, resulting in improved technical tribology.