RM 74-02

Skeletonised automatic-winding tourbillon movement with hours, minutes and variable-geometry rotor.

Power reserve: around 50 hours (± 10%)

The baseplate and bridges of the RM 74-02 are machined from 18K 5N red gold and 18K 3N yellow gold respectively, both microblasted and bevelled by hand.

The skeletonised baseplate and bridges were subjected to intensive and complete validation tests to optimise their resistance capacities

Rotor specifications:
• Heavy outside edge and heavy edge ring in 18K red gold
• Weight segment in platinum
• Automatic OneWay® winding system in ceramic with ball bearings
• Bidirectional winding system

This variable-geometry rotor has been incorporated within the in-house CRMT5 calibre, making it possible to set the rotor according to the owner’s activity level.

The setting is modified by adjusting the two moveable weights into the correct position and fixing them in place with spline screws. The inertia of the movement is increased when the two weights are closer together; the barrel then rewinds more quickly. If the weights are positioned at the extremities of the rotor, the inertia is decreased and the barrel winds more slowly.

Gold Carbon TPT® is a high-tech material comprising some 600 layers of parallel filaments obtained by separating out carbon fibres. The layers, no more than 30 microns thick, are impregnated with a black matrix.

They are then assembled on a dedicated machine, which stacks the layers, varying the orientation of the fibres by 45° between layers and alternating them with 24K yellow gold leaf layers.

As gold is a noble material in chemical terms, it was very difficult for the NTPT and Richard Mille engineers to ensure it ‘fused’ correctly with carbon. The composite is then heated to 120°C at a pressure of 6 bars in a kiln similar to that used for the production of aeronautics parts, after which it is ready to be machined at Richard Mille.