The heart of a KF movement is a peerless technical epic saga. A measure of time distilled by a rare watchmaker where the word compromise has no place. A meeting of superlatives or when watchmaking is thought of as a whole from the smallest screw to the last bridge pursuing a goal: to sublimate the invisible. Here, we propose to lift the veil on certain technical aspects of watchmaking by taking place at the workbench with our Master Watchmaker Karsten Fraessdorf.
A watch is composed on average of 260 components housed in a case designed to fit on a wrist. What a great and beautiful sight! Not only are these produced in-house here in La Chaux-de-Fonds, but I finalise each of them before assembling them.
Speaking of time, it takes an average of 2 years to make a KF watch. Everything starts with the first sketches and ends with the handing over of the watch to the customer, including of course the manufacture of the components, their assembly, adjustment and final inspection. This process can be shortened or extended depending on the type of customer requests.
The Spirograph model beats the rate of 18,000 vibrations per hour or 2.5 Hertz. Thus, the escape-wheel belonging to the watch’s regulating organ spins on its axis 18,000 times per hour. That is 432,000 beats per day, 3,024,000 per week and 157,680,000 per year. An impressive yet sedate pace guaranteeing excellent precision.
My power reserve is 84 hours. This means that the movement of my watch operates during this period of time without requiring any manual winding via the crown. However, to improve chronometric accuracy, this autonomy is deliberately reduced to 66 hours by means of the “Maltese cross” stopwork mechanism.
In a mechanical calibre, the energy is stored thanks to the mainspring (barrel spring) which redistributes it in the form of an energy curve. The latter is not always identical and is referred to as the amplitude of the watch. Just after the mechanism is fully recharged, this amplitude can reach 300°, dropping to 270° after one hour and during the rest of its autonomy. This applies to “traditional” mainsprings.
The “Maltese cross” stopwork mechanism serves to neutralise the first turn of the mainspring. We then choose a stronger spring serving to achieve a 300° amplitude that remains stable during the two days of power reserve. The resulting linear amplitude enables us to make the best possible chronometric adjustments.
Apart from the possibilities related to diver’s watches, our calibres are water-resistant to a depth of 50 metres (5 ATM).
In response to technological developments, this new movement is setting new standards in terms of resistance to magnetic fields – an important criterion when choosing a tourbillon. It thus maintains its accuracy regardless of its environment. The reinforced anti-magnetism characteristic of KF complies with the ISO 764-2020 established in 2020, as implied by its codename. This means that not only the escapement, but the entire Novamag® 01 movement – and more generally the watch as a whole – are endowed with enhanced anti-magnetic properties.
Innovation means patents. To this end, I have filed a double patent on the balance-wheel whose oscillations regulate the movement and which features two circular peripheral weights. Customisable at will, these two elements lend a uniquely playful touch to the Tourbillon. While this construction is above all a nod to marine chronometers, which also operated with large balance-wheels, it is also a reference to chronometry and its origins.
My balance-spring is composed of a “Straumann” alloy which means it is anti-magnetic and able to resist magnetic fields of up to 1,000 Gs. This is important at a time when we are seeing ever-increasing sources of exposure (laptops, electric cars, etc.). I am determined to counteract these magnetic fields because components otherwise become magnetized and end up disrupting the running of the watch, which in turn causes time loss. The choice of these alloys naturally makes component production twice as expensive compared with standard materials, but you don’t count the cost when pursuing a passion for precision!
While watchmaking is my vocation, chronometry – the exact measurement of time – is my favourite playground. To this end, I meticulously craft my components, especially the balance-springs. In order to operate at an optimum level, a balance-spring must ‘breathe’ concentrically so as to avoid any unbalance (loss or gain of the watch in vertical positions). A balance-spring moving non-concentrically will disturb the balance of the balance-wheel and thus impair the precision of the watch.
The “Phillips” balance-spring represents an evolved version of the “Breguet” balance-spring in that it enables concentric breathing. Unfortunately, it only acts on the outer half of the balance-spring (7/14 coils). This problem can be solved by adding an internal “Grossmann” curve. This addition is all the more important given that the negative impact of non-concentricity is greater on the inner and outer coils. In this way, all the coils of the balance-spring will be able to work concentrically.
Except for special requests, I gladly choose steel for my watch cases because I like to create everyday watches. Steel is lighter, so it is often more comfortable to wear on a daily basis. In the same way, the calibre proposed is based on a “pillar” construction, which also allows us to lighten the weight of the movement. This technique is a reference to marine chronometers, which remain inexhaustible sources of inspiration.
© 2020 Montres KF