Description
Moritz Grossmann Benu Hamatic White Gold
Reference: MG-002303
Throughout millennia, researchers and inventors dreamed of building a perpetual motion machine; a device that would continue to move indefinitely once started. Without any external source of power, it was believed that the machine itself could generate an unlimited amount of energy. It was only with the formulation of the law of conservation of energy in the middle of the 19th century that physics quashed the principle of perpetual motion. Nevertheless, people’s fascination for the concept remained.
While Moritz Grossmann’s HAMATIC calibre does not purport to be a perpetual motion machine (because it draws its kinetic energy from an external source), the cleverly designed concept is fascinating and beautiful and draws inspiration from this dream.
So, how does it work?
Moritz Grossmann’s HAMATIC adopts a pendulum-style hammer weight to convert the energy generated through the wearer’s movements to the ratchet wheel and the mainspring in the barrel, meaning that an external energy source makes the dream of infinite motion come true.
It’s, therefore, safe to say that the HAMATIC is one of the most beautiful and complex examples of ‘would-be’ perpetual motion.
The Benu HAMATIC collection is available in different case materials and dial colours, each reflecting a different style and preference.
The clean, pure aesthetic of the white opaline dial, hand-annealed violet hands and solid white gold case affords a fresh, contemporary look to this special timepiece inspired by the history of horology. Any watch lover or collector will appreciate the craftsmanship and heritage of this beautiful piece.
Technical data
Movement
Manufacture calibre 106.0, manually wound, adjusted in five positions
Special features
Grossmann balance; click pawl in reduction gear; adjustment with Grossmann micrometer screw on cantilevered balance cock; pillar movement with 2/3 plate and pillars made of untreated German silver, hand-engraved 2/3 plate and cantilevered balance cock; wide, horizontal Glashuette ribbing, double-band snailing on the mainspring barrel; raised gold chatons with pan-head screws; separately removable clutch winding mechanism; stop seconds for hand setting; automatic winding with oscillating hammer, bidirectional click wheels; idler with pawl clicks, manual yoke winder
Functions
Hours and minutes, subsidiary seconds with stop seconds
No. of parts
312
No. of jewels
38, 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
Balance
Diameter 10.0 mm, frequency 21,600 semi-oscillations/hour
Power reserve
72 hours when fully wound
Operating elements
Crown for winding the watch, and setting the time
Case dimensions
Diameter: 41.0 mm, height 11.35 mm
Movement dimensions
Diameter: 36.4 mm, height: 5.15 mm
Case
Three-part, in 750/000 white gold
Dial
Solid silver, opaline, with printed Roman numerals
Hands
Manually crafted, steel, annealed to a brown-violet hue
Crystal and display back
Sapphire crystal, antireflective coating on one side
Strap
Hand-stitched alligator leather with pin buckle in 750/000 gold
Using your HAMATIC
– When you first put your watch on or your watch has stopped, wind it with 30 – 40 rotations of the crown to ensure stable operation
– To wind, turn the crown between your thumb and index finger using back and forth movements
– If daily worn while you are active, the watch has an achievable power reserve of 40 – 50 hours = optimum power range with minimal strain on the movement
– Achieve the maximum power reserve of 72 hours either through moving more intensively or hand winding with approximately 70 rotations of the crown
Before you first put on your HAMATIC or if it has stopped, we recommend winding the watch with 30-40 rotations of the crown to ensure it runs reliably and at a stable rate. Always turn the crown back and forth between your thumb and index finger. To prevent damage to the seal, try to avoid unilateral pressure, which can occur if you wind your watch with one finger.
When you wear the HAMATIC, it will generate the required winding energy from the movement of your arm. Wearers with average activity levels who use the watch daily will achieve a maximum power reserve of 40-50 hours. In this winding state, the movement will be in the optimal power range, ensuring minimal strain on the individual components of the movement.
You can achieve the maximum power reserve of 72 hours with more intensive movement or winding by hand. The excess energy is then transferred via a so-called slip or sliding bridle that acts as a safety clutch in the mainspring barrel. This is a reliable way of preventing the mechanism from being damaged. Approximately 70 rotations of the crown are required to fully wind the watch by hand.
Note: Classic watch winders developed primarily for automatic rotor watches will not achieve optimal winding performance on the HAMATIC because the hammer winder mainly relies on the dynamic, varied arm movements of the wearer.
Calibre 106.0
The movement used in the HAMATIC bears the designation “Calibre 106.0”. It draws on the historic technique of so-called hammer winding that was implemented in a handful of pocket watches and some early automatic wristwatches. As the winding mass in some pocket watches looked similar to a hammer, the term hammer winding was coined for this type of construction.
The main component is a pendulum mass featuring a limited arc and mounted outside the centre of the movement to generate the winding energy. The biggest challenges faced in manufacturing this watch are probably the limited hammer arc and varying intensity of the wearer’s movements. Two basic scenarios need to be covered by this winding system in a reliable and energy-efficient manner:
- To convert gentle deflections with as little loss of winding energy as possible.
- Fast movements must be attenuated and absorbed.
The HAMATIC incorporates precautions that allow for both scenarios. While the bidirectional pawl mechanism transfers even the smallest movements to the movement, the intricately crafted end springs consistently put the excessively accelerated hammer and its solid gold hammer weight back in place.
