Limited Edition
First launched in 2015, the LM Perpetual has been crafted since in red gold, platinum, white gold and titanium. A new 18kt yellow gold case with blue face now joins the series: a limited edition of 25 pieces.
Beginning with a blank sheet of paper, MB&F and independent Irish watchmaker Stephen McDonnell have completely reinvented that most traditional of horological complications: the perpetual calendar. The result is Legacy Machine Perpetual, featuring a visually stunning in-house movement developed from the ground up to eliminate the drawbacks of conventional perpetual calendars.
LM Perpetual features a fully integrated 581-component caliber − no module, no base movement − with a revolutionary new system for calculating the number of days in each month. And it holistically reinterprets the aesthetics of the perpetual calendar by placing the full complication on dial-free display underneath a spectacular suspended balance.
The fully integrated, purpose-built movement of Legacy Machine Perpetual has been designed from scratch for trouble-free use: no more skipping dates or jamming gears, and the adjuster pushers automatically deactivate when the calendar changes.
Traditional perpetual calendar mechanisms use a 31-day month as the default and basically "delete" superfluous dates for the months with fewer days by fast-forwarding through the redundant dates during changeover. A traditional perpetual calendar changing from February 28 to March 1 scrolls quickly through the 29th, 30th and 31st to arrive at the 1st.
LM Perpetual turns the traditional perpetual calendar system on its head by using a "mechanical processor" instead of the conventional space-consuming grand levier (big lever) system architecture. The mechanical processor utilises a default 28-day month and adds extra days as required. This means that each month always has the exact number of days required; there is no fast-forwarding or skipping redundant days. And while the leap year can only be set on traditional perpetual calendars by scrolling through up to 47 months, LM Perpetual has a dedicated quickset pusher to adjust the year.
Using an innovative system developed especially for Legacy Machine Perpetual, the subdials appear to "float" above the movement with no visible attachments. The skeletonised subdials rest on hidden studs, which is technically impossible with traditional perpetual calendar mechanisms because they would block the movement of the grand levier.
"I call perpetual calendars boomerang watches because they come back for repair so often," says Maximilian Büsser. "The mechanisms jam, block, break, or jump days when they shouldn't."
Technical Specifications:
The case, in 18kt yellow gold, measures 44mm x 17.5mm. It has double AR-coated sapphire crystals and it is water resistant to 30 meters.
Movement is a Swiss manual-wind MB&F in-house caliber with 41 jewels, 18,000 vph and a power reserve of 3 days. Fully integrated perpetual calendar developed for MB&F by Stephen McDonnell, featuring dial-side complication and mechanical processor system architecture with inbuilt safety mechanism. Manual winding with double mainspring barrels. Bespoke 14mm balance wheel with traditional regulating screws visible on top of the movement. Superlative hand finishing throughout respecting 19th century style; internal bevel angles highlighting hand craft; polished bevels; Geneva waves; hand-made engravings. Functions are: hours, minutes, day, date, month, retrograde leap year and power reserve indicators.
Legacy Machine Perpetual uses a patent-pending "mechanical processor" consisting of a series of superimposed disks. This revolutionary processor takes the default number of days in the month at 28 because, logically, all months have at least 28 days and then adds the extra days as required by each individual month. This ensures that each month has exactly the right number of days. There is no "skipping over" redundant days, so there is no possibility of the date jumping incorrectly.
Using a planetary cam, the mechanical processor also enables quicksetting of the year so that it displays correctly in the four-year leap year cycle, whereas traditional perpetual calendar mechanisms require the user to scroll through up to 47 months to arrive at the right month and year.
Doing away with the calendar's big lever has allowed for completely new aesthetics not possible when conventional systems are in use. MB&F's mechanical processor enables the center of the complication to be used, thereby saving space and allowing design freedom as the full dial is no longer necessary.
Legacy Machine Perpetual takes advantage of its fully integrated movement to place the perpetual calendar mechanism on top of the movement main plate so that it can be appreciated from above. Legibility is often an issue with perpetual calendars due to the sheer number of indications, and LM Perpetual addresses this by using skeletonised subdials (except for the time indication) that appear to float above the complication with no apparent support from below.
It comes on a black hand-stitched alligator leather strap with a gold folding buckle.
Friends responsible for LM Perpetual
Concept: Maximilian Büsser / MB&F
Product design: Eric Giroud / Through the Looking Glass
Technical and production management: Serge Kriknoff / MB&F
Movement design and finish specifications: Stephen McDonnell and MB&F
Movement development: Stephen McDonnell and MB&F
R&D: Ruben Martinez, Simon Brette and Thomas Lorenzato / MB&F
Wheels, pinions, movement, axis component: Paul-André Tendon / Bandi, Daniel Gumy / Decobar, Le Temps Retrouvé and Swiss Manufacturing
Balance wheel bridge and plates: Benjamin Signoud / AMECAP
Balance wheel: Andréas Kurt / Precision Engineering
Balance spring: Stefan Schwab / Schwab-Feller
Bridges: Rodrigue Baume / HorloFab
Perpetual calendar parts: Alain Pellet / Elefil
Hand-engraving of movement: Glypto and Eddy Jaquet
Hand-finishing of movement: Jacques-Adrien Rochat and Denis Garcia / C-L Rochat
PVD-treatment: Pierre-Albert Steinmann / Positive Coating
Movement assemblage: Didier Dumas, Georges Veisy, Anne Guiter, Emmanuel Maitre, and Henri Porteboeuf / MB&F
After-Sales service: Thomas Imberti / MB&F
In-house machining: Alain Lemarchand and Jean-Baptiste Prétot / MB&F
Quality Control: Cyril Fallet / MB&F
Case: Alain Lemarchand and Jean-Baptiste Prétot / MB&F
Gold ingots CoC ( Chain of Custody) : Nathalie Guilbaud / Cendres et Métaux
Case decoration : Bripoli
Dial: Hassan Chaïba and Virginie Duval / Les Ateliers d'Hermès Horloger
Buckle: G&F Chatelain and Nathalie Guilbaud / Cendres et Métaux
Crown and correctors: Cheval Frères
Hands: Isabelle Chillier / Fiedler
Sapphire crystals: Martin Stettler / Stettler
Strap: Multicuirs
Presentation box: Olivier Berthon / SoixanteetOnze
Production logistics: David Lamy and Isabel Ortega / MB&F
Other versions of the Legacy Machine Perpetual are available in platinum, 18kt white or rose gold, or in titanium. All are limited editions.
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