SJX Watches
In-Depth: The MB&F; LM Perpetual and Stephen McDonnell’s Innovation
When it comes to perpetual calendars – perhaps the most objectively useful complication – the MB&F; Legacy Machine Perpetual, or LM QP for short, sits neatly between classical architecture and iconoclastic construction. Now almost a decade old having been launched in 2015, the LM QP is a mechanical marvel coming from the mind of Stephen McDonnell. The LM QP’s beauty lies in Mr McDonnell’s rethinking of the perpetual calendar complication while integrating historical concepts. Rethinking the QP A perpetual calendar, or quantième perpétuel (hence “QP”), is a complex and layered mechanism, which makes it a challenging complication to implement in watches. Naturally, not all perpetual calendars are created equal, some being more innovative and others more classical in their construction. The first-ever serially produced perpetual calendar wristwatch, the Patek Philippe ref. 1526 that debuted in 1940; the basics of the perpetual calendar mechanism would remain largely unchanged for decades after The issue with classical calendar constructions is their vulnerability to wear and tear, shock, or careless operation by the user. Ironically, the most forward-thinking of perpetual calendar mechanisms try to solve these problems, but sometimes suffer from reliability issues rooted in the radical concepts employed. Mr McDonnell’s construction of the LM QP smartly manages to eliminate traditional weaknesses while avoiding new problems. The result is a reliable and innovati...
