What is the utility of high frequency? Giulio Papi, head of Audemars Piguet (Renaud & Papi) ponders the question and answers: “In fact, the higher the frequency, the better the chronometry. This is the reason for making a higher-speed escapement.”

 

The Pioneer

In 1969, Zenith was not technically the first to bring out an automatic chronograph movement. But what many forget is that this groundbreaking calibre beat at 36,000vph, which was unusual, but not unheard of, in its day. However, it does remain the only calibre from this era beating at this rate still in use, and until recently, uniquely enjoyed its particular claim to fame.

The reason for its high number of beats is to improve accuracy. However, one of its early problems arose in the area of lubrication: the extreme escapement speed caused oil to splatter into areas where it was not desired. Such issues with higher-speed movements resulted in the use of special, low-viscosity lubricants not normally used in watchmaking at that point.

The El Primero Stratos Flyback Striking 10th houses the calibre 4057B, beating at a very brisk 5Hz

The El Primero Stratos Flyback Striking 10th houses the calibre 4057B, beating at a very brisk 5Hz

It is also important to note that balance frequency is today not the only factor in a watch’s accuracy. Other elements that may affect precision include the balance wheel and balance spring being well-made and perfectly matched and poised. Also, when a frequency is higher, other details and variances may come to the fore that would otherwise not be a factor in a watch with a slower frequency, because they are now multiplied by the higher beat.

Needless to say, in the 42 years since its introduction, Zenith has mastered every aspect of the high-speed El Primero movement beautifully, and it is today a reliable and highly accurate movement.

New Technology and Materials

The last 15 years have brought about revolutionary changes in how a mechanical watch is manufactured. One of the catalysts has been CNC machining, which allows for more precision in manufacturing individual components. The next was the world of new materials, beginning with nickel-phosphorus LIGA components and Mimotec’s easy access to the technology — which suddenly allowed for components with tolerances that are almost no longer perceptible, and parts that no longer need lubrication. This was closely followed by silicon technology. Silicon will change the face of escapements and allow for much higher frequencies, since neither wear nor lubrication will be an issue.

Watchmaker Martin Braun recently explained this point very succinctly, “For years, I had thought about improving the standard Swiss lever escapement for my own movements. What I was envisioning was simply not possible with conventional materials and production methods. It was the advent of silicium [silicon] for watchmaking that allowed me to finally realize the solution I imagined.” In short, this had to do with the Swiss lever escapement’s angles, which in his opinion have represented a compromise between effectivensss and the capillary effect (which keeps oil in its proper place). “This no longer needs to be adhered to since an escapement predominately comprising silicium components functions without oil,” he commented.

Don’t miss:

High Speed Escapements, Part 2: A Field Survey
High Speed Escapements, Part 3: Different Approaches

Excerpted from an article by Elizabeth Doerr, co-founder of Quill & Pad, in REVOLUTION’s archives.

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