RM 038 TOURBILLON BUBBA WATSON 538.25.91

TECHNICAL SPECIFICATIONS OF THE TOURBILLON RICHARD MILLE RM 038 BUBBA WATSON

Tonneau case – numbered Limited Edition- available in magnesium WE 54.

CALIBER RM038 : manual winding tourbillon with hours and minutes.

Dimensions: 48 mm x 39.70 mm x 12.80 mm.

MAIN FEATURES
(MANY OF WHICH ARE MAJOR TECHNICAL INNOVATIONS)

POWER RESERVE
Circa 48 hours.

VARIABLE INERTIA, FREE SPRUNG BALANCE
The free-sprung balance provides better reliability in the event of shocks, movement assembly and disassembly. It also guarantees better chronometric results over an extended period of time.

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 a profitable winding gain (circa 20 %), especially during the winding start. It is also helpful in the distribution of 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 allows for compensation of possible variations in the engagement of the going train, thus insuring excellent torque transmission with a distinct improvement in performance.

BASEPLATE AND BRIDGES MADE OF TITANIUM
The manufacturing of these components in grade 5 titanium allows the whole assembly to be given great rigidity, as well as precise surface flatness which is essential for the perfect functioning of the gear train. The skeletonized baseplate was subjected to separate and extensive validation tests to insure optimal strength requirements.

SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES
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.

OTHER FEATURES
• Dimensions of movement: 30.60 mm x 29.37 mm
• Thickness: 7.55 mm
• Tourbillon diameter: 10.90 mm
• Balance diameter: 9.12 mm
• Number of jewels: 19
• Balance: Glucydur, 2 arms, 4 setting screws, inertia moment 11.50 mg.cm2, angle of lift 53°
• Frequency: 21,600 vph (3Hz)
• Balance spring: Elinvar by NIVAROX
• Shock protection: KIF ELASTOR de KE 160 B28
• Barrel shaft in nickel-free chronifer (DIN x 46 Cr13 +S) with following characteristics:
• stainless, antimagnetic, suitable for tempering.

CASE
The RM 038 case is made of an extremely rugged and light alloy called magnesium WE 54. Magnesium WE 54, used for the RM 038, is an alloy composed of 89% magnesium, 6% yttrium and 5% rare earths. It is one of the lightest metals used in construction and has excellent property retention capacities at elevated temperatures. The mechanical properties of magnesium WE 54 are more isotropic than conventional magnesium alloys. After a long and delicate machining phase, theses alloys are given a new  electro-plasma oxidation treatment called Miarox®. The resulting coating is a cristalline oxide ceramic  with an exceptional resistance. This improves both the durability and scratch resistance of this alloy as well as its wear and corrosion properties. This treatment applied to magnesium WE 54 is biocompatible and is used in aerospace, automotive industries and the medical sector. The tripartite case is water resistant to 50 meters, ensured by two Nitril O-ring seals. The case is assembled with 12 spline screws in grade 5 titanium and abrasion resistant washers in 316L stainless steel.

SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE 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.

INTERIOR FLANGE
Minute flange in white carbon fiber.

CRYSTAL
• Bezel side: In sapphire (1800 Vickers) with anti-glare treatment (both sides)
• Thickness: 1.20 mm
• Case back: In sapphire with anti-glare treatment (both sides)
• Thickness: at the center 1 mm and outer edges 1.73 mm

FINISHING

MOVEMENT
• Baseplate and bridges in micro-blasted grade 5 titanium
• Anglage and polishing by hand
• Sapphire blasted milled sections
• Straight line grain finish of the upper surfaces
• Polished sinks

STEEL PARTS
• Sapphire blasted surfaces
• Satin finished surfaces Anglage and polishing by hand
• Straight line grain finish of the upper surfaces
• Straight line grain finish of the upper surfaces
• Polished sinks

PROFILE TURNING
• Lapped and polished ends
• Burnished pivots

GEAR WHEELS
• Concave chamfering with a diamond tool
• Circular finished faces
• Rhodium-plating (before cutting the teeth)
• Minimum correction applied to the wheels in order to preserve geometry and performance