An extra flat movement is something most subtle and elegant in the world of horology since the expertise of the watchmaker resides in achieving something almost invisible.
The constraints of producing this model are made even more challenging given the limited space available.
In the case of the automatic extra flat wristwatch the RM 033, one of its characteristic lies in the placement of the RMXP1 caliber’s automatic micro rotor to the side rather than the center of the movement, thus saving precious millimeters in total height.
As a result, this movement has a diameter of 33.00 mm while its thickness is only of 2.60 mm.
To provide perfect weight distribution for this decentral rotor to function optimally, it has been designed to wind bi-directionally and is manufactured from solid Platinum, allowing for efficient winding as well as compact dimensions of the extra flat skeletonized movement.
The caliber RMXP1, with 29 jewels and beating at 3Hz, has a free sprung balance with variable inertia. This type of balance wheel represents the ultimate in innovation. It guarantees greater reliability when subjected to shock and also during movement assembly and disassembly, hence better chronometric results over time.
The regulator index is eliminated and a more accurate and repeatable adjustment is possible thanks to 4 small adjustable weights located directly on the balance.
For the creation of the RMXP1 caliber, the bottom plate bridges and balance cock are made of titanium. The manufacturing of these components in grade 5 titanium with Titalyt® treatment for the bottom plate and black PVD coating for the bridges allows the entire ultra-thin assembly to be given great rigidity, as well as precise surface flatness which is essential for the perfect functioning of the gear train as well as stability of the movement. The baseplate and all titanium parts have been subjected to separate and extensive validation tests to insure optimal strength requirements.
The round case design of the RM 033 measures 45.70 mm x a mere 6.30 mm in thickness. The curving case back has become the trademark of the entire Richard Mille collection. This tripartite case with a complete integration of the lugs into the case system is water resistant to 30 meters, ensured by two Nitril O-ring seals. It is assembled with 16 spline screws in grade 5 titanium and abrasion resistant washers in 316L stainless steel.
Many details form the signature of this simple and elegant watch, such as the free sprung balance with variable inertia, a power reserve of 42 hours, the extensive use of spline screws throughout the movement, the rigorous design and execution of the case, the ceramic crown sealed with double seal O-rings.