MB&F - MB1F Horological Machine No3 Frog Zr
MB&F - MB1F Horological Machine No3 Frog Zr

MB1F Horological Machine No3 Frog Zr


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HM3 Frog, look me in the eyes!


The limited edition MB&F Horological Machine No. 3 Frog, or HM3 Frog, is the first derivative watch based on Maximilian Busser’s Horological Machine No. 3. Busser and his Friends are known to release about one completely new limited edition watch each year, yet they also have special model variations based on their standard collection of Horological Machine watches. The MB&F Frog is, therefore, a variation of the original Horological Machine No. 3 and is available in two versions – the MB&F HM3 Frog TI in Grade 5 titanium and the MB&F HM3 Frog Poison Dart Frog in black PVD coated zirconium with 18k yellow gold screws. The latter case design is a limited edition of only 10 pieces.


Why the Frog?

The story says that one of Maximilian Busser’s customers had commented on the two dome-like hours and minutes structures on the original MB&F Horological Machine No. 3 and said that they looked like two bulbous frog’s eyes sticking out of the water. Maximilian Busser liked the idea and decided to design an HM3 declination that looked even more like a frog, thus replacing the initial watch cones with a flat top design by real, perfectly shaped round domes. These sapphire crystal domes would really have the aspect of two protruding eyes of a frog. With no movement of its head, the frog can see in many directions. With no movement of his wrist, the wearer of the HM3 Frog can read time from many different angles. Crafting the semi-spherical sapphire crystal domes of the watch is incredibly demanding since a slight imperfection would generate a magnification effect. Under the crystal are the actual rotating domes machined from solid aluminium, a material chosen for its optimal strength to weight ratio. They are literally paper-thin and only weigh 0.5g, reducing energy requirements to an absolute minimum.


Adapting the movement design

The problem for Maximilian Busser was that with the movement design on the original MB&F Horological Machine No. 3 the hour dome turned once each 24 hours. But with the new design of the Horological Machine No. 3 Frog, Jean-Marc Wiederrecht (Agenhor) needed to adapt the design of his movement so as to enable the dome to turn once each 12 hours. This was apparently the cause of numerous movement changes.


A rotor for the legacy

Nonetheless, the basic movement design of the limited edition MB&F Frog remains the same as for the Horological Machine No. 3 and is composed of 304 components. The most interesting and innovative feature in the design of the HM3 movement is that it has literally been turned upside down so as to allow for a permanent exhibition of the solid 22k red gold winding rotor of the watch as well as the high-speed oscillations of the balance wheel. This three-dimensional horological engine was designed by Jean-Marc Wiederrecht (Agenhor) and is powered by a Sowind base. The 22k red gold iconic MB&F watch rotor is shaped like a “battle-axe” and has been called by MB&F the “mystery rotor”; it is placed dial-side and appears symmetrically balanced, apparently defying the laws of physics. Yet this symmetry is really an optical illusion as mass has been shaved off the underside of the blade on one side of the rotor, allowing it to function properly. Maximilian Busser’s HM3 rotor is definitely a rotor for the legacy.

Placing the rotor and regulator on the dial side required an inverted movement, only possible thanks to two large ceramic bearings that efficiently transmit time up to the revolving hours and minutes cones, each functioning as a completely separate dial. The first dome of the watch is for the hours and rotates in 12 hours. The second dome of the watch is for the minute's indication and rotates in 60 minutes. On the top of each sapphire crystal dome is a teardrop shape that indicates where you look to read the hours or the minutes. The teardrops also remind you with a large “H” and a large “M” whether you are reading the hours or the minutes. They are also a reminder that this watch is a proper Horological Machine with a case design for the legacy.

Unlike the two limited edition versions of the original HM3 watches (the Sidewinder watch and Starcruiser watch), which had straps attached to them in two orientations, the black PVD coated zirconium (“Poison Dart”) or Grade 5 titanium Frog watch has one single orientation, which probably suits the design best. You can observe the movement of time through the top and bottom mounted sapphire crystals. You will also find a date display ring on the top part of the watch case, where a small arrow on the case tells you were to read the date. In a subsequent emblematic variation of the Horological Machine No. 3, the HM3 Megawind, Max Busser decided to go one step further and remove the date display ring. Such a design enables the implementation of an even larger rotor, capable of mega wind the watch with even more power. 

Technical specifications

  • Zirconium
  • 47 mm x 50 mm x 16 mm
  • Three-dimensional horological engine by Jean-Marc Wiederrecht/Agenhor
  • automatic
  • Hours, Minutes, Seconds, Date, Day/Night indicator
  • Black alligator

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