MB&F Legacy Machine Perpetual In 18k Yellow Gold

First launched in 2015, the Legacy Machine Perpetual has been crafted since in red gold, platinum, white gold and titanium. A new 18k yellow gold case with striking blue face now joins the series.

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 an in-house movement – developed from the ground up to eliminate the drawbacks of conventional perpetual calendars.

LM Perpetual is powered by a fully integrated 581-component with 72 hours power reserve. It does not need a module or base movement but instead is equipped with a revolutionary new system for calculating the number of days in each month. 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.

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 29^th, 30^th and 31^st to arrive at the 1^st.

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.

The open dial reveals the full complication and suspended balance. 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.

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.

The LM Perpetual in 18k yellow gold is limited to 25 pieces and worn on a black, grey, brown or blue hand-stitched alligator strap. The case size is 44 millimetres.

mbandf.com