Armin Strom Unveils Technically Advanced Caliber with Mirrored Force Resonance

In a bold move, Armin Strom unveils its most complicated movement to date – and one that impacts the world of watchmaking.  After several years of research and development, the brand has released the patented Caliber ARF 15 with Mirrored Force Resonance technology. Unveiled at Salon QP in London recently and making its debut in an 18-karat gold Fire case,  the new  in-house movement offers stabilization of the going rate, conservation of energy and more.

To understand the watch, a little lesson in resonance may help. Essentially, resonance is a phenomenon of physics that states that two oscillating bodies in close proximity influence each other and eventually synchronize. This is the concept Armin Strom embraces in its new Mirrored Force Resonance caliber. The movement features  dual regulators developed for maximum precision — and displayed in all its mechanical beauty on the dial side of the watch.

The Concept of Resonance

Resonance is a sophisticated and demanding horological technique that has rarely been attempted, let alone mastered. In the pursuit of horological accuracy, precision, and rate stability resonance has generally involved utilizing two independent mainsprings, gear trains, escapements, and balances, each connected by a rack and pinion to allow fine tuning of the distance between them. Precise adjustment of the distance between the two regulators is necessary to incite resonance, which sees the two balances finding a concurrent rhythm in opposite directions so as to continuously average out errors for maximum accuracy.

One body in motion relays its vibrations to its surroundings. When another body with a similar natural resonant frequency to the first receives these vibrations, it will absorb energy from the first and start vibrating at the same frequency in a sympathetic manner. The first body acts as the “exciter,” while the second acts as the “resonator.”

The advantages of resonance are multiple, but the most important factor is that it provides a stabilizing effect on timekeeping, which translates to better accuracy. As already mentioned, It also conserves energy. Finally, it reduces the negative effects on timekeeping accuracy due to outside forces such as shock to the balance staff, which in turn keeps the rate more stable and increases precision.
An outside shock that slows one of the balances down increases the speed of the other one by the same amount; both balances will strive to get back in resonance, thereby averaging and minimizing the effects of the outside influence as they find their rhythm.

The making of the ARF 15

Armin Strom’s  resonant Caliber ARF15 is a classically constructed manually wound movement that was conceived, manufactured, assembled, and regulated in-house. It beats at a 3.5 Hertz (25,200 vph) frequency, allowing the observer to really appreciate the patented, resonant regulators in action. The resonance clutch spring needed to realize the Mirrored Force Resonance’s twin display of seconds was so technical that the brand’s team, under the direction of technical director Claude Greisler, was left with no choice other than to create what it needed in house. Like Calibre ARF15, the resonance clutch spring comprises only a traditional horological material: steel. Greisler and his team spent fully two and a half years perfecting the shape and characteristics of the spring: calculating, optimizing, simulating, testing, and improving again and again until the spring had the optimal, unique form needed to connect the two sets of oscillators, each comprising twin balance wheels and balance springs.

Since the two connected oscillators make their revolutions in opposite directions, which is eminently visible on the dial side of the watch, one rotating clockwise and the other counterclockwise, the animated elements look much like they are performing a magic trick. If the 48-hour power reserve has been exhausted and the movement requires a fresh injection of energy through winding, the twin balance wheels need approximately 10 minutes to become synchronous. In case of any outside influence in the form of shock, it takes only a few minutes for the two balances to find their resonant rhythm once again thanks to the use of balance spring studs, which receive the impulses. The pusher at 2:00  resets the luminous twin seconds’ displays to zero, simultaneously resetting the twin balance wheels.

This exciting new 43.4mm world premier watch features the brand’s typical skeleton dial and has a transparent sapphire crystal case back for viewing the meticuloulsy finished movement. The Mirrored Resonance Fire model is being built in a very limited edition of 50 pieces and retails for about 67,000 Swiss francs.

The History of Resonance in watchmaking

The phenomenon of synchronized motion in horology has fascinated watchmakers since the time of Christiaan Huygens (1629-1695). Huygens, inventor of the pendulum clock, was the first to discover the resonance of two separate pendulum clocks, which he logically surmised should keep slightly different time. When hung from a common beam, however, the pendulums of the adjacent clocks synchronized; subsequent researchers confirmed that the common wooden beam coupled the vibrations and created resonance. The two pendulums functioned as one in a synchronous manner. In the eighteenth century, Abraham-Louis Breguet demonstrated his mastery of the phenomenon with his double pendulum resonance clock.

Tech Specs of the CALIBRE ARF15: