In 2009, MB&F was four years into its creative expression of mechanical art. Horological Machines No. 1 and No. 2 had established the guiding principles of the Maximilian Büsser & Friends collective: audacious design, transformative micromechanics, untrammeled imagination. Then came Horological Machine No. 3; HM3 had everything that HM1 and HM2 had before —the design, the micromechanics, the imagination— but its defiant three-dimensional construction shot MB&F into hyperspace. One year later, in 2010, the vehicle that transported MB&F into a new universe proved its versatility and cemented its place in the hearts of MB&F lovers everywhere, by morphing into the Tribe’s first and best-loved mascot: the HM3 ‘Frog’.

With two globular ‘eyes’ that rotated to give the hours and minutes. A widely grinning ‘mouth’ revealing the occasional bright flicker of the signature MB&F battle-axe rotor as it swept past a date scale. A glistening ‘skin’ of titanium, red gold or exotic zirconium. HM3 Frog may have been small as a specimen of amphibious pondlife, but it was mighty on the wrist as it leaped to iconic status at the crossroads of kinetic art and horology.

Now, 10 years after its debut, HM3 Frog makes its comeback, radiantly exposed in a sapphire crystal case, yet still with a hidden message to be discovered. Presenting Horological Machine No. 3 ‘Frog X’.

For the first time, the HM3 engine is showcased in all its glory, used here in its MegaWind iteration that trades the date display for an expanded rotor. Two paper-thin domes, milled out of aluminum to be as light as possible, indicate the hours and minutes, rotating under markers designed to resemble the lateral pupils of a frog’s eyes. Super-LumiNova accents, like the vivid colors that nature endows upon its feistiest creatures, reveal themselves in fluorescing segments under the rotor and on the time-display domes.

The HM3 Frog X 10th-anniversary limited editions are available in three versions of 10 pieces each with blue, purple, or turquoise rotors and matching colors of SuperLumiNova and case gaskets.

Things to Know About the Watch

If the first HM3 Frog was an animal of land and lake, Frog X brings us into the arboreal realms of the transparent-skinned glass frogs of Central American cloud forests. The transparent case of Frog X is entirely of sapphire crystal, one of the hardest known minerals, and must be milled with diamond-tipped tools or special high-tech carbide bits. Despite MB&F’s experience with the most advanced sapphire-crystal producers —as demonstrated in earlier MB&F creations such as the HM4 Thunderbolt and HM6 Alien Nation—, machining the case of HM3 Frog X still provides a considerable challenge. The separate sapphire domes not only need to be uniform in size, but they must also be exactly uniform and consistent in thickness and curve so as not to create any final optical distortions in the reading of the time.

Those looking at the winding and setting crown of HM3 Frog X, expecting to see the usual battle-axe insignia, will be slightly baffled to find a smooth, highly polished disc —although exceptionally observant individuals may notice a slight irregularity in its reflection of light. At just the right angle, with just the right kind of directional light and just the right receiving surface, the final secret of the fully exposed Frog X is revealed. A secret signal, created by sculpting the metal crown at microscopic levels to allow it to reflect light in highly specific ways, is the key to unlocking the MB&F battle-axe. To create the secret battle-axe signal, MB&F worked with light-sculpting techniques pioneered by Rayform, a Swiss company whose technology has various applications, from design to anti-counterfeiting measures.

By micro-forming a metal surface at levels nearly imperceptible to the human eye, Rayform technology is able to direct incident light beams to be reflected in customized ways, creating a light-encoded message or design that can be viewed on any relatively uniform surface.

Corundum, commonly known in its gem-quality form as sapphire, is one of the hardest minerals known to man. It is surpassed in hardness only by a few other materials, notably diamond (crystalline carbon), which rates a 10 on Moh’s scale of hardness, while corundum is rated at 9. This exceptional hardness means that sapphire watch crystals are virtually scratch-proof, providing unparalleled legibility and material integrity over the long term, not to mention imparting a level of prestige that is not associated with regular silicate glass or transparent polycarbonate —the two most common alternatives to sapphire watch crystals.

Concurrently, this also means that sapphire is extremely challenging to machine in complex three-dimensional shapes, a challenge that is compounded by the small machining tolerances required in watchmaking. Since its very first creations, MB&F has worked with ever-increasingly complicated sapphire crystal components; the HM2 “Sapphire Vision” editions, the double-arched crystals of the HM4 Thunderbolt, and the hallucinatory body of the HM6 Alien Nation being prime examples.

The Movement

HM3 Frog X incorporates the distinctive HM3 engine in its MegaWind Final Edition version. Harmoniously crafted bridges, the oscillating balance wheel, gearing, and MB&F’s iconic battle-axe automatic winding rotor are all open to view on the dial side. This allows the wearer to fully appreciate the art and craft of the HM3 engine by drawing the viewer’s gaze inside the highly complex machine; a machine comprising more than 300 fine-finished, high-precision components. The engine of HM3, built by award-winning master watchmaker Jean-Marc Wiederrecht, is based on a Girard-Perregaux calibre, which has been literally turned upside down to allow for an uninterrupted view of the enlarged 22K gold and titanium winding rotor and the oscillations of the balance wheel.

Time indications are usually located on the top, or dial side, of a movement. As the HM3 engine is inverted to display its operation, an efficient solution was needed to bring power from the bottom of the movement to the time-indication domes at the top. Standard pinions set in jewels would have required complex, friction-generating gearing, and would require support top and bottom —a factor which would increase the height of the movement, and thus the watch.

Instead of standard jeweled pinions, HM3 features two large-diameter (15mm) high-tech ceramic bearings. Because of their large diameter, these bearings minimize the number of friction inducing gears and, due to the rigidity resulting from their ultra-high precision design and manufacture, they only require support at one end (the base), allowing for a thinner movement.

 The two 22K gold blades of the MB&F battle-axe rotor make what is called a ‘mystery’ rotor because, in appearing to be symmetrically balanced instead of having a visibly off-centered mass, they seem to defy the laws of physics. This is achieved by machining the underside of one of the gold blades to a razor-thin edge, so reducing its mass. The enlarged iteration of the MegaWind rotor came about via a suggestion from frequent MB&F collaborator, Finnish watchmaker Stepan Sarpaneva —the collaborator for the HM3 MoonMachine and MoonMachine 2— highlighting once again the foundational values of MB&F as a collective of individual talents, conjunction of deep-rooted relationships, a confluence of worlds.

The new HM3 Frog X 10th-anniversary is available in three versions of 10 pieces each with blue, purple, or turquoise rotors and matching colors of SuperLumiNova and case gaskets.

Sticker Price $152,000 USD. For more info on MB&F click here.