Perhaps one of the top five biggest news of the year and a watch that we think for sure will be a prize recipient at the GPHG next year. May we now present you MB&F's first perpetual calendar. The new MB&F Legacy Machine Perpetual is a perpetual calendar timepiece that is reinventing the most traditional horological complication. The new MB&F LM Perpetual, developed from the ground up with independent Irish watchmaker Stephen McDonnell, breaks all codes and perspectives on how we've looked at perpetual calendars up until now.

While conventional perpetual calendars are generally modules comprising the complication which is fitted on top of an existing movement, the calendar indications are synchronized by a long lever —called 'grand levier' in French— running across the top of the complication and passing through the center. Clearly something impossible when you have a suspended balance on top of the dial fitted with the world’s longest balance wheel pinion to connect that elegantly suspended balance, hovering above the top of the movement, to the escapement on the back of the movement. Well, MB&F and Scott McDonnell figured out a way around it by developing an in-house perpetual calendar movement with 581 parts that allows for the new complication to be fully appreciated dial-side with no module on top of a base movement. Ladies and gentleman this is a groundbreaking perpetual calendar in all the sense of the word. Available in platinum or 18K 5N+ red gold, the Legacy Machine Perpetual is fitted with a case measuring 44 mm x 17.5 mm with satin-brushed finished case band and mirror polished horns and bezel. By the way, the watch is water resistant to 30 meters and with the same proportions in terms of width as the Legacy Machine No.1.

The Dial

With a revolutionary new system for calculating the number of days in each month, the new MB&F Legacy Machine Perpetual reinterprets the aesthetics of the perpetual calendar by placing the full complication on a dial-free display underneath its spectacular suspended balance. Traditional perpetual calendars —unlike the new MB&F LM Perpetual— 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. The dial of the LM Perpetual is the movement itself with three skeletonized white lacquered ring subdials and one white lacquered subdial for the hours and minutes.

Using an innovative system developed especially for the MB&F Legacy Machine Perpetual, the subdials appear to float above the movement with no visible attachments. The skeletonized subdials rest on hidden studs, which is technically impossible with traditional perpetual calendar mechanisms because they would block the movement of the 'grand levier'. While the configuration of the dial might appear slightly cluttered, in person this watch is simply a treat for the eyes. Hours and minutes are located at 12 o’clock between the elegant arches of the balance, the day of the week at 3, a useful power reserve indicator at 4, a month indicator at 6, retrograde leap year indicator at 7 and date at 9 o’clock. All indicators are perfectly visible thanks to the stunning contrast between the white lacquer and the blued hands.

The Crown & Pushers

Another great thing that the MB&F Legacy Machine Perpetual sorts out, is the drawbacks that some traditional perpetual calendars have including dates that can skip, being relatively easy to damage if adjusted while the date is changing as the complications are usually comprised of modules powered by base movements. The fully integrated, purpose-built movement of the new MB&F Legacy Machine Perpetual has been designed from scratch for trouble-free use with no more skipping dates or jamming gears and the adjuster pushers automatically deactivate when the calendar changes, so no problems there either.

Four nicely finished pushers are set around the case band —two on each side. The pushers are easy to use and are calibrated in a way where strong pressure is necessary to make them adjust the calendar, thus avoiding accidental changes. This is also an excellent way to avoid unwanted scratches to the case band as most perpetual calendars would require the use of a correcting pen/stylus to press the diminutive recessed correctors commonly found on perpetuals.

While 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 big lever —grand levier— system architecture. The mechanical processor utilizes 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 quick-set pusher to adjust the year.

The Movement

The movement powering the MB&F LM Perpetual was fully developed in-house as an integrated perpetual calendar developed for MB&F by Stephen McDonnell, featuring dial-side complication and mechanical processor system architecture with inbuilt safety mechanism. Stephen McDonnell was born in Belfast, Northern Ireland in 1972. He has been interested in watchmaking ever since he remembers, tinkering and 'repairing' his grandfather’s
clocks as a precocious four-year-old. After completing a degree in theology at Oxford University, McDonnell returned to Belfast and gradually fell into repairing clocks for a number of watch and clock shops. This led to the realization that watchmaking might well be a career after all. After completing a one-week Rolex course —until then his experience had been virtually exclusively with clocks— McDonnell moved to Neuchâtel, Switzerland in 2001 to do a six-month course at WOSTEP —Watchmakers of Switzerland Training and Educational Program. Upon completion, he was offered an instructor position at WOSTEP, which he held until 2007 when he decided to set up as an independent watchmaker. McDonnell became an accomplished, though self-taught, movement designer, which provided him with a very rare skill set as watch constructors rarely have hands-on practical watch experience. McDonnell moved back to Belfast with his wife and two children in 2014. An absolute horological perfectionist, McDonnell likes to control all aspects of the development process from conception through to 3D design, construction, the creation of technical plans, and
prototyping.

The LM Perpetual project began with a meeting between Maximilian Büsser and Stephen McDonnell. McDonnell had been a long-time friend of the brand and played an instrumental role in the realization of MB&F’s very first timepiece, Horological Machine No.1. As Büsser was thinking of developing a perpetual calendar for the fourth watch in the Legacy Machine collection, McDonnell replied that he had an idea for a perpetual calendar that addresses many of the drawbacks associated with conventional examples. Three years and many sleepless nights later, Legacy Machine Perpetual was born.

The manual wound movement composed of 581 parts, is composed of double mainspring barrels, bespoke 14 mm balance wheel with traditional regulating screws visible on top of the movement, superlative hand finishing throughout in 19th century style, internal bevel angles, Geneva waves, 41 jewels and handmade engravings. The movement beats at a frequency of 18,000 vph to provide a 3-day power reserve. The exquisitely finished movement is of course fully visible via the display case back.

On typical perpetual calendars, 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. “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.” The MB&F 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. The mechanical processor also enables an inbuilt safety feature that disconnects the quick-set pushers during the date changeover, eliminating any risk of damage while the date is changing. While the conception and development of this mechanical processor-controlled perpetual calendar complication is a noteworthy achievement in itself, Stephen McDonnell went even further by managing to place all 581 components of the movement in virtually the same sized case as LM1.

The Strap

In good old MB&F fashion, the matte hand-stitched alligator strap was created by Camille Fournet. The strap is black for the platinum model and dark brown for the red gold one. The strap is equipped with the traditional folding clasp in matching metal.

On the Wrist & Pricing

On the wrist, the new MB&F Legacy Machine Perpetual fits true to its size, very comfortably and with indisputable wrist presence. Its mesmerizing design and beauty are rounded out by the idea behind the creation of a completely unique perpetual calendar mechanism in one of the most beautiful watches we've reviewed this year. Available in a limited edition of 25 pieces for each metal variation —platinum or 18K red gold—, we are confident these will fly off the showcases very quickly. If you want to really see what 'haute horlogerie' is about, you need to see one of these watches in person. Better yet, if you decide to buy one right away.

Sticker Price $176,000 USD for platinum and $145,000 USD for 18K red gold. For more info on MB&F click here.