designboom's friends over at MB&F have just revealed their newest horological machine no. 3 'frog',
which is meant to bring a child's sense of awe and playfulness to high-end watchmaking.


HM3 frog face

the protruding eyes of the (amphibian) frog enable it to see in many directions without having
to turn its head. the watch's bulbous domes are the opposite, acting as a feature of enabling
the time to be seen easily from many angles without having to turn one's wrist. the 'frog' differs
from its predecessor, the HM3 in that it is the aluminum domes that rotate under the sapphire crystals
in the 'frog', whereas it is the hour and minute hands that rotate around their respective stationary cones
on the HM3.


black frog profile


rotating domes of this size and shape generated a number of technical challenges.
the hour and minute domes are machined from solid aluminum - chosen for its optimal strength
to weight ratio. the domes weight just over 0.5 grams each. they are first milled from the outside in,
resulting in a paper-thin wall thickness of just 0.28 mm, reducing energy requirements to a minimum.

even the fabrication of the semi-spherical sapphire crystal domes was incredibly demanding
and only recently even possible at all. this is due to the fact that any slight imperfection in the sapphire
might introduce a disconcerting magnification effect. the sapphire has to be shaped and polished
to be perfectly uniform.

the hour dome of the watch, rotates in 12 hours compared to the 24 revolution of the HM3 hour hand,
and as the over-sized date wheel is driven from the hours, the gearing driving the date had to be
reworked as well.



the engine

the HM3 frog is only made in a limited edition of 12, featuring mark-resistant black-coated
titanium with green rotor.


the engine - movement double

design details:

movement:
- three dimensional horological engine designed by jean-marc widerrecht / agenhor;
girard-perregaux oscillator and gear
- balance oscillating at 28, 800 bph
- 22k blued rose gold battle-axe shaped 'mystery' automatic winding rotor
- hour and minutes information transmitted via ceramic ball bearings to rotating domes
- it contains 36 functioning jewels and 304 components
- HM3 frog functions with the hour and day / night indicator on one dome
(aluminum dome rotating in 12 hours), minutes indicated on the second dome
(aluminium dome rotating in 60 minutes), date around the movement

case:
- grade 5 titanium / blue 222K gold rotor; limited edition of 12 black titanium / green 22K gold
(black treated with mark-resistant silicon oxide) screwed-down crown
- dimensions (exclusive of crown and lugs): 47mm x 50mm x 16mm
- 53 case components

the dials of the watch are rotating aluminum domes with stationary hands. the strap is made
from a hand-stitched alligator with 18K white gold & titanium custom designed deployment buckle.



HM3 black frog