MB&F Legacy Machine Perpetual
By Shereen Shabnam
Made in collaboration between MB&F and the Northern Irish watchmaker Stephen McDonnell, the Legacy Machine Perpetual combines outstanding design and meaningful horological innovation—both hallmarks of truly great watchmaking. The LM Perpetual can be summed up with complexity simplified with integrity and beauty.
The unorthodox configuration of the watch allows the skeletal displays to seemingly hover between the movement and the elevated balance. This engaging and imaginative arrangement results in a beautiful perpetual calendar. The movement offers near-instantaneous date changes, easier setting, and improved reliability with the added artistic value of 19th-century decorative motifs. Initial production is limited to 25 pieces in red gold and 25 in platinum.
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.
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 (patent pending).
LM 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. 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.
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.
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.
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 long lever (in French: 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.
The year 2015 saw the launch of Legacy Machine Perpetual featuring a fully integrated perpetual calendar. Today MB&F alternates between launching contemporary, resolutely unconventional Horological Machines and historically inspired Legacy Machines