MB&F reinvents the perpetual calendar in Legacy Machine Perpetual
In aiming to produce unconventional Horological Machines and historically-inspired Legacy Machines, the world’s first ever horological concept laboratory, MB&F, presents the fourth generation in its Legacy Machine family in a fully integrated and reinvented perpetual calendar: The Legacy Machine Perpetual
The saga began in 2011 when MB&F launched the round-cased LM1, the first in the Legacy Machine (LM) collection – a tribute to the 19th century watchmaking excellence through the reinterpretation of complications from the great horological innovators of yesteryear to create contemporary objets d’art. The release was followed by the LM2 and LM101, the first MB&F LM to feature a movement developed entirely in-house.
This year, on the occasion of MB&F’s first decade in the industry, it adds another timepiece in its LM collection that looks back at one of the most traditional horological complications in the watchmaking history: The perpetual calendar. Conventional perpetual calendars are generally modules comprising the complication, which is fitted on top of an existing movement. The calendar indications are synchronised by a grand levier running across the top of the complication and passing through the centre. As the date changes, this long lever transmits information to the appropriate components and mechanisms by moving backwards and forwards.
The existence of the grand levier means that there can be nothing in the centre of the complication that might impede it – like a suspended balance with its staff running right down through the centre of the movement to an escapement on the back. This lever also means that perpetual calendars require a full dial, which may have cut-outs or windows, as it is impossible to support subdials with studs because they would block the motion of the big lever mechanism.
In the traditional grand levier system, perpetual calendars assume that, by default, all months have 31 days. At the end of months with less than 31 days, the mechanism quickly skips through the superfluous dates before arriving at the 1st of the new month. Any manipulation or adjustment of the date during changeover can result in damage to the mechanism, requiring expensive repairs by the manufacturer. The dates can also jump or skip during changeover, negating the whole point of the perpetual calendar in the first place, which is not requiring adjustment for years or decades.
Inspired by the beauty of this complication and driven to get the solution for its drawbacks, the MB&F owner and creative director Maximilian Büsser met up with Northern Irish watchmaker Stephen McDonnell to address the concerns of the conventional perpetual calendar. Three years and a great many sleepless nights later, the Legacy Machine (LM) Perpetual was born.
The remarkable timepiece features a visually stunning in-house movement with fully integrated 581 components – no module, no base movement – with a revolutionary new system for calculating the number of days in each month. The LM Perpetual reinvents the traditional perpetual calendar system by using a patent-pending 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 has the exact number of days required so 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, the LM Perpetual has a dedicated quickset pusher to adjust the year. The mechanical processor also enables an inbuilt safety feature that disconnects the quickset pushers during the date changeover, eliminating any risk of damage while the date is changing. Hence, this timepiece promises no more skipping of dates or jamming in gears since it has the adjuster pushers that automatically deactivate when the calendar changes.
Aside from its outstanding use of mechanical processor, the LM Perpetual’s manual winding movement is powered with double mainspring barrels. It also flaunts its bespoke 14mm balance wheel that has superlative hand finishing that reflects a 19th century style. With power reserve of 72 hours and 41 jewels, the movement also features handcraft internal bevel angles and hand-made engravings.
Meanwhile, 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 centre of the complication to be used, thereby saving space and allowing design freedom as the full dial is no longer necessary. The LM Perpetual reinterprets the aesthetics of the perpetual calendar by placing the full complication on dial-free display underneath a spectacular suspended balance. The harmonious mechanical beauty of the eye-catching balance hovering on high is connected to the escapement on the back of the movement by what is likely to be the world’s longest balance staff.
The LM 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. Using an innovative system developed especially for LM 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.
Taking a clockwise tour of the dial, at 12 o’clock we see the hours and minutes nestled between the elegant arches of the balance; day of the week at 3 o’clock, power reserve indicator at 4 o’clock, month at 6 o’clock, retrograde leap year indicator at 7 o’clock, and date at 9 o’clock.
Launched in a limited edition of 25 pieces in 18K 5N+ red gold and 25 pieces in platinum 950, the LM Perpetual finishes off its fascinating look with a black or dark brown hand-stitched alligator strap with gold or platinum folding buckle matching case material.
