Credits: Article and images by Jeremiah Chan @ Revolution Watch Magazine. See the original article here - https://revolutionwatch.com/the-royal-oak-jumbo-takes-flight/
For starters, AP clearly had the intention of putting a selfwinding flying tourbillon movement into the Jumbo’s case right when the decision was made to update the caliber 2121 for the new Jumbo. The RD#3’s caliber 2968 was developed in conjunction with the new Jumbo’s caliber 7121, and the two movements share much of the same architecture with one another (position of the keyless works, wheel train and regulating organ). To achieve the caliber 2968’s ultra-thin height of 3.4mm, a mere 0.2mm more than the caliber 7121, AP focused on redesigning the traditional tourbillon’s composition itself. A traditional tourbillon, while seemingly complex visually, its mechanical theory is actually quite easy to understand. Have a look here if you’re still scratching your head about how a tourbillon works. As for a flying tourbillon, it is simply a tourbillon with the top bridge removed, making it seem like it isn’t being held down by any structure.
Going back to the use of lightweight titanium for the tourbillon cage like in the 1986 Ra, AP also removed the traditional fixed fourth wheel that is found underneath the balance and escapement and replaced it with a peripheral driving system. And just like that, the height of the tourbillon cage is reduced, which in turn reduced the movement height by one level, and the caliber 2968 can be fitted into the Jumbo’s case. Energy transmission to the tourbillon is also improved due to the smaller angular pitch between the peripheral drive wheel and the rest of the wheel train. Translation: the RD#3 will keep better time over a longer period of time, which is a good thing.
Those are the technical bits but there have been aesthetic changes made to the flying tourbillon as well. Comparing the architecture of the caliber 2950 and 2968, the balance wheel arms can now afford to be made thicker with the use of titanium, which provides more stability to the cage as it rotates. The hairspring stud disc has been removed from underneath the anti-shock unit and the balance wheel itself no longer uses timing weight screws that protrude from the wheel but much more streamlined timing weights that sit flat within the perimeter of the wheel itself. Lastly, the escapement itself has been redesigned to reveal more of the inner workings of the movement. All these changes have been implemented to create a feeling of lightness and airiness that complements the thinness of the Jumbo’s case. According to Michael Friedman, Head of Complications, “The movement architecture was designed to offer a unique view of the smaller case while showcasing an engaging contrast of hand-finishing techniques throughout.”
Looking through the sapphire case back, the feeling of airiness persists with a semi-skeletonized movement with open-worked bridges for the automatic winding wheel train, barrel, and movement going train. The bridges themselves are no longer decorated with traditional Côtes de Genève but the more contemporary straight-graining of traits tirés. In contrast, the exquisite polished beveling of the exterior edges and even for the interior angles of the skeletonized portions showcase AP’s expertise in classic hand finishing techniques. The similarly decorated, bi-directional open-worked oscillating weight is made of 22-carat pink gold which is rhodium plated to match the movement bridges. The commemorative ’50 Years’ logo will only be used for Royal Oaks made in 2022, which could in all likelihood be a Royal Oak collector’s dream.
If the RD#3’s movement is as contemporary in its technical and aesthetic presentation, the dial-side doesn’t disappoint in its use of original Royal Oak dial design cues. The flying tourbillon at 6 o’clock, which replaces the 16202’s ‘AP’ logo, is able to sit on the same level as the dial, bringing it closer to the crystal than ever before. The Petite Tapisserie guilloche-patterned dial is colored in Bleu Nuit, Nuage 50, the iconic midnight blue of the original Royal Oak 5402. The original dial used a galvanic bath to produce the blue shade which tended to oxidize over time (which many collectors prefer), but the new Jumbos have blue dials obtained from physical vapor deposition (PVD). This color coat creates a more uniform and lasting surface on the dial. AP would have you know that the method of creating the Tapisserie pattern is no longer taught in watchmaking schools and will continue to be a design aesthetic that is unique to AP’s watches.
Credits: Article and images by Jeremiah Chan @ Revolution Watch Magazine. See the original article here - https://revolutionwatch.com/the-royal-oak-jumbo-takes-flight/