Moritz Grossman ATUM Hamatic

At Baseloworld 2018, German watch manufacture Moritz Grossman unveiled a prototype of their first self-winding watch, which features a modern interpretation of an older-generation device: a pendulum mass, referred to as an automatic hammer mechanism.

Christened ‘Hamatic’, this piece transforms automatic winding into a fascinating visual experience within a brand new 106.0 calibre. Compared with standard rotor-based systems, this automatic hammer system is a filigreed work of art. A bi-directional hammer with a heavy gold head sits on a fine stem.  Not only can it be seen clearly as it oscillates behind the display glass back, it is also visible through cut-outs in the dial.  As well as being a visual treat, the system is highly energy efficient.  And, fully-wound, it has a power reserve of 72 hours.

The aesthetics are inspired by pocket watches crafted in Moritz Grossmann’s nineteenth century workshop.  Long Roman numerals adorn the clean face of this watch. The super-fine, poire shaped hands – as always hand-sculpted in the manufacture – also imitate an original antique piece.  This striking look sits effortlessly in a rose gold case.

This brand new,324-part, 39 jewel mechanism will be optimised over the summer prior to release around year-end.  It is a classic pillar movement with a 2/3 plate but was extensively redesigned for the Hamatic.

The bi-directional automatic hammer mechanism relies on the interaction of the hammer body with the hammer head and the hammer spring. The oscillation of the hammer spring is transferred to the hammer body via a sapphire roller. The system is designed for efficiency and dependability.  Under gentle motion of the hammer, energy transmission is nearly loss-free. At higher accelerations, excessive deflections are controlled by a catch slider and fixed end stops.

The Hamatic system features a click mechanism integrated in the rotary axis of the hammer body; it serves as a bidirectional winder. The oscillations of the hammer body are picked up by two click levers and converted into a continuous rotary motion powered by the alternating direction of rotation of the click wheels. The rotary motion is transferred to the free wheel via the reduction wheel and then to the ratchet wheel of the mainspring barrel.

The manual winder is designed as a yoke winder that is mounted on a separate bridge. Its simple and functionally reliable design has proved to be an ideal complement to the automatic winder. When the Hamatic system is activated by motion, the manual winder is disconnected from the ratchet wheel by the yoke.

In the manual winding mode, the reduction gear is isolated from the ratchet wheel by a click-pawl idler. When the crown is pulled, the balance is stopped to enable hand-setting. At the same time, the crown wheel and the ratchet wheel are disengaged by the yoke. When the crown is pushed home again to the winding mode, the balance stop is deactivated and the yoke pivots into the ratchet wheel.

Versions

Reference MG-001708
Case: 750/000 rose gold
Dial: Opaline with Roman numerals
Hands: Manually crafted, steel, annealed to a brown-violet hue

Technical details

Movement
Manufacture calibre 106.0, adjusted in five positions
Diameter: 31.6 mm, height 4.1 mm
No. of parts: 324
No. of jewels: 39, of which 3 in screwed gold chatons
Escapement: Lever escapement
Oscillator: Shock-resistant Grossmann balance with 4 inertia and 2 poising screws, Nivarox 1 balance spring with No. 80 Breguet terminal curve, Gerstenberger geometry
Balance: Diameter 10.0 mm, frequency 21,600 semi-oscillations/hour
Power reserve: 72 hours when fully wound

Functions
Hours and minutes, subsidiary seconds with stop seconds

Operating elements
Crown for winding the watch, and setting the time

Special features
Grossmann balance; click pawl in the reduction gear train; adjustment with Grossmann micrometer screw on a cantilevered balance cock; pillar movement with 2/3 plate and frame pillars in untreated German silver, 2/3 plate and balance cock hand-engraved; broad horizontal Glashütte ribbing, 2-band snailing on the mainspring barrel; raised gold chatons with pan-head screws; separately removable clutch winding mechanism; stop seconds on the balance rim for handsetting; self-winding with oscillating hammer, bidirectionally acting click wheels; idler with pawl clicks, manual yoke winder; optimised mainspring barrel bearings on a separate barrel axis

Case
Three-part, precious metal
Diameter: 41.0 mm, height 11.35 mm
Crystal and display back: Sapphire crystal, antireflective coating on one side

Dial
Solid silver, white, with printed Roman numerals
Hands: Manually crafted, steel, annealed to a brown-violet hue

Strap
Hand-stitched alligator strap with prong buckle in precious metal

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