We witnessed the birth of the Horological Machine No. 9 in 2018.
Nicknamed HM9 "Flow," it was a tribute to the automotive and aeronautic designs from the 40's and 50's, and featured a case that had the "flowing" aerodynamic silhouette iconic of those times.
MB&F founder Maximilian Büsser described the engine inside HM9 as "the most beautiful movement we've created to date" and MB&F has taken the next step to showcase all the magnificence inside with a transparent sapphire crystal shell.
The new Horological Machine No. 9 'Sapphire Vision,' HM9-SV, features an outer hull of sapphire crystal and precious metal, curved and bubbled and precisely fitted together in three parts. It is sealed with a proprietary combination of patented three-dimensional gasket and high-tech compound bonding process.
In order to seal the sapphire crystal exterior components into one watertight case, new solutions had to be created. A patented three-dimensional rubber gasket was already used in the original HM9 Flow to ensure water resistance when the tripartite case was bolted together. The 3-D gasket remains in HM9-SV, but the sapphire crystals are fused with the metallic frame thanks to a high-tech bonding compound, mastered via an in-house process involving a vacuum and high temperature.
The result is a seal resistant to 3ATM (30m) of water pressure, despite practically invisible seams between the sapphire components and the minimalistic frame in 18K gold.
MB&F’s Max Busser on the HM9, "When I say it took us three to four years, it actually took us 13 years to come up with something like that."
Inspired by the dynamic profiles of automotive and aviation mid-century design, HM9 Flow with its curvilinear silhouette, boasts a geometrically complex combination of milled sapphire crystal and titanium case elements. Reminiscent of a jet engine, and hence the name 'Flow', a manual-winding movement developed fully in-house sits inside. Twin balance wheels beat independently on each "fuselage", while the central body contains a planetary differential that averages the output of both balances to provide one stable reading of the time. Read Story
To further reduce sensitivity to shocks, the HM9-SV editions feature a new shock-absorbing system: helicoidal springs placed between the movement and the case. The springs are crafted by laser from a solid tube of polished stainless steel, offering excellent elasticity and limited lateral displacement.
A Tribute to One of the Greatest Watchmakers Alive
Max Busser: "The HM9 movement is a is a tribute to one of the greatest watchmakers alive called Philippe Dufour. Philippe created in 1996, the Duality, the first-ever wristwatch with two balanced wheels and a differential."
"The first time I had a Duality in my hand and I turned it round and I saw those two balance wheels. It was in probably 1999, [almost] 20 years ago, and I remember thinking 'wow, if I created something that has two balance wheels I would want to see them'."
HM9 Sapphire Vision comes in four editions, each limited to only five pieces: two editions with 18K red gold frame, combined with a NAC-coated black or a PVD-coated blue engine; and two editions with 18K white gold frame, featuring a PVD-coated purple or a red gold plated engine.