This is the latest MB&F watch to be produced in cooperation with another watchmaker. Past pieces included this HM2.2 Black Box watch done with French Alain Silberstein. For the HM3 MoonMachine, MB&F selected to work with Finnish Stepan Sarpaneva; his eponymous brand is Sarpaneva. The HM3 MoonMachine is a real hybrid between the design of both MB&F and Sarpaneva.

Sarpaneva has become known as the moon phase watch brand. I don’t always know if Sarpaneva wished for this, but the grimacing face on his moon phase indicators has become very synonymous with the brand. It therefore makes sense that in any collaboration he does, the eye-catching face be a large part of the design. Before starting his own brand, Sarpaneva worked with such greats as Christophe Claret, Piaget, and Vianney Halter (among others). He is really almost a lone operation, making his watches by hand in Helsinki.

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Together Max Busser and Stepan Sarpaneva selected the HM3 Frog to serve as the base of the new limited edition watch. You can see one of my several hands-on articles with an HM3 Frog watch here. The Frog was a revised version of the original HM3 with more “eye-like” hour and minute indicators. One notable difference for the “eyes” is the inclusion of an iconic Sarpaneva shape taken from his watch cases. You can see the gear-like shape in the center of the “eye domes”.

That shape again is placed on the sapphire crystal over the moon phase indicator and automatic rotor. It serves as the actual indicator showing the phase of the moon with the moon faces underneath. This layout offers full views of the faces all the time, along with the phase of the moon with the indicator window.

Sarpaneva revised the date wheel mechanism on the HM3 to insert the moon phase. I believe it required the formation of a new disc which rather than having a 31 day cycle, would have an approximately 29.5 day cycle (the lunar cycle). It is a clever way of integrating a moon phase indicator into a watch without modifying the movement too much. Sarpaneva actually does this with the Soprod movements he uses in his own watches.

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Inside the HM3 MoonMachine is a base Girard-Perregaux movement that has of course been modified for this purpose. The movement is an automatic, and in this case has a “sky style” 22k gold automatic rotor that is seen behind the moon phase disc. This “celestial” background disc comes in different colors depending on the MoonMachine model (of which there are three). The most beautiful ones in my opinion are those which are blued. Little stars are cut into the parts and they look really nice. MB&F did a good job of integrating a Sarpaneva theme while very much keeping intact the MB&F DNA in the MoonMachine.

There will be three versions of the HM3 MoonMachine watch. Please note that the pictured ones are prototypes (I am referring to the chipped crystal on the gold version). The first version will be in titanium with a light blue “sky” and 18k white gold moon phase faces. Next is a black coated titanium version with a darker blue “sky” and 18k white gold moon phase faces. Last is an 18k red gold version with an anthracite “sky” and 18k red gold moon phase faces. Each of the three models are limited to just 18 pieces each. All versions are priced at $98,000.

MOONMACHINE– Technical Specifications from MB&F

MOONMACHINE is based on a specially configured HM3 Frog and the moon complication was imagined, designed and created by Stepan Sarpaneva. It is available in three limited editions of 18 pieces each.


Three-dimensional horological engine designed by Jean-Marc Wiederrecht/Agenhor;

Powered by a Girard-Perregaux base, modified by Stepan Sarpaneva

Balance oscillating at 28,800 bph.

PVD coated and star-pieced 22k gold automatic winding rotor

Hour and minutes information transmitted via ceramic ball bearings to rotating domes.

Number of jewels: 36 (all functional)

Number of components: 319


Hour on one dome (aluminum dome rotating in 12 hours)

Minutes on second dome (aluminum dome rotating in 60 minutes)

Moon phase displayed by dual moons rotating under a Korona ring


1. Natural titanium case, white gold moon faces, light blue sky, limited edition of 18 pieces
2. Black titanium case, white gold moon faces, dark blue sky, limited edition of 18 pieces
3. Red gold case, red gold moon faces, anthracite sky, limited edition of 18 pieces
Indication domes configured perpendicular to wrist.
Screwed-down crown
Dimensions (exclusive of crown and lugs): 47mm x 50mm x 19mm
Number of case components: 55

Sapphire crystals:

Domes and both display backs with anti-reflective treatment on both faces.


Rotating aluminum domes – 0.58g,

Strap & Buckle:

Black hand-stitched alligator with 18K gold & titanium custom designed deployment buckle

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