MB&F is reinventing the perpetual calendar

Text: Press
Photo: MB&F

A new 18k yellow gold case with striking blue face now joins the series: a limited edition of 25 pieces of Legacy Machine Perpetual

First launched in 2015, the LM Perpetual has been crafted since in red gold, platinum, white gold and titanium. 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.

Legacy Machine Perpetual MB&f
The fact that the new complication looks sensational and can be fully appreciated dial-side is just one of the many benefits offered by the new movement, controlled by a mechanical processor

Legacy Machine Perpetual features a fully integrated 581-component calibre − 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 perpetual calendar is one of the great traditional complications, calculating the apparently random complexity of the varying numbers of days in each month − including the 29 days in February during leap years. But traditional perpetual calendars do have a few drawbacks: dates can skip; they are relatively easy to damage if adjusted while the date is changing; and the complications are usually compromises of modules powered by base movements.

LMP YG Wristshot Lres

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, so no problems there either! 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.

LMP YG Front Lres

With its open dial revealing the full complication and suspended balance, it’s the harmonious mechanical beauty of LM Perpetual that really steals the show. And in an interesting technical twist, that 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.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.

LMP YG Back Lres

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.

LMP YG Face Lres
Legacy Machine Perpetual can be yours for 147.000 EUR + tax

MB&f Legacy Machine Perpetual

Legacy Machine Perpetual is available:

– in platinum 950 with blue face (limited to 25 pieces);

– in 18k red gold with grey face (limited to 25 pieces);

– in 18k white gold with purple face (limited to 25 pieces);

– in 18k white gold with dark grey face;

– in grade 5 titanium with green face (limited to 50 pieces);

– and now in 18k yellow gold with blue face (limited to 25 pieces)

Engine

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 14 mm 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.

Power reserve: 72 hours

Balance frequency: 18,000bph / 2.5Hz

Number of components: 581

Number of jewels: 41

Functions/indications

Hours, minutes, day, date, month, retrograde leap year and power reserve indicators

Case

Material: 18k 5N+ red gold, 18k white gold, 18k 3N yellow gold, platinum 950, grade 5 titanium.

Dimensions: 44 mm x 17.5 mm

Number of components: 69 components

Water resistance: 30 m / 90′ / 3 atm

Sapphire crystals

Sapphire crystals on top and display back treated with anti-reflective coating on both faces

Strap & buckle

Black, grey, brown or blue hand-stitched alligator strap with gold / platinum / titanium folding buckle matching case material.

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