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Frederique Constant Slimline Monolithic Manufacture

One of the most noticeable trends in technical watchmaking since the end of the Second World War has been the evolution of watches with higher and higher frequency oscillators. A pendulum clock might have a pendulum that beats once per second. A watch has a balance, which can swing back and forth much more rapidly – a modern watch movement usually runs at 28,800 beats per hour, or eight beats per second. Some movements (the Zenith El Primero, for instance) can beat even faster, at 36,000 beats per hour. The new Frederique Constant Slimline Monolithic Manufacture, from Frederique Constant, has a new type of oscillator, which runs at 40Hz – that’s a staggering 288,000 beats per hour. The watch was introduced in March, and even in the aftermath of Watches & Wonders, it’s still one of the most technically interesting watches of the year.
Any watch or clock is, at its most basic, an oscillator (the pendulum, a balance wheel) with a driving system (a mainspring in a watch, a falling weight in a pendulum clock) and a mechanism that both counts the oscillations, and drives the oscillator. This is the escapement.
Above, you can see the mainspring barrel on the left. The barrel rotates under the impetus of the mainspring inside it, and the teeth on the barrel gear to the pinion of the center wheel. The gear train ends, on the right, at the escape wheel and lever. (The balance wheel isn’t shown, for clarity.) As the balance swings back and forth, it unlocks the lever once per swing, letting the gear train advance. The gearing is set up so that the center wheel turns once per hour, and drives the hour and minute hands.
So why would you like to have an oscillator that beats faster than 36,000 vph? The answer is that such an oscillator should be more stable – that is, less apt to drift from its expected frequency. If a balance wheel were to always beat at exactly its expected frequency, you would have a perfect watch, but in reality, a number of factors can cause the frequency of a balance to vary, making the watch sometimes too slow, and sometimes too fast. Frequency varies when the oscillator is affected by outside forces, which can be aging lubricant in the watch itself, or changes in temperature, or the presence of magnetic fields, or physical shocks and changes in the position of the watch. The reason quartz watches are generally so much more accurate than mechanical watches is that a quartz oscillator beats at a much higher frequency – the tuning-fork-shaped quartz crystal hums at 32,768 beats per second.
The Frederique Constant Slimline Monolithic Manufacture, on the other hand, uses a miniaturized version of the flexible one-piece oscillator design we first saw from Zenith, first in the Defy Lab, and then in the Defy Inventor. Rather than the usual combination of balance, balance spring, and lever, the monolithic oscillator in the Monolithic Manufacture uses a one-piece (hence, “monolithic”) silicon oscillator, which has integrated into it flexible central blades that allow it to oscillate, and an integrated lever. The oscillator has two weights mounted on it, which can be used to regulate the rate of the oscillator, just as rim weights on a balance can be used for the same purpose.

The connection between the Monolithic Manufacture and the Defy Inventor is of course, not a coincidence. Both were developed by a company called Flexous, under the direction of CEO Nima Tolou; Flexous was founded in 2012 and is a branch of surprisingly punctuated tech incubator YES!Delft.
The oscillator itself is a circular disk of silicon, and the blades, lever mechanism, and escape wheel are all silicon as well. Above, the escape wheel is at 12:00 (and is driven by the gear train, from the mainspring barrel) and on either side, you can see the teeth of the lever mechanism. The weights for adjusting rate are the two bars to the left and right, with grooves etched into the silicon to provide increments for the watchmaker. When running, the oscillator vibrates too fast for the naked eye to see individual vibrations, and the seconds hand advances 80 times per second, appearing to glide smoothly around the dial.
Conventional watchmaker’s electronic timing machines don’t work on an escapement that runs this fast, so the rate of the oscillator is adjusted with the help of a laser-controlled high-speed camera, capable of firing up to 250,000 times per second.
While a standard balance in a mechanical watch usually swings through an arc of around 300º, the Monolithic Oscillator vibrates in a much smaller arc – just 6º, which is par for the course for very high-frequency oscillators.
Aside from the greater rate stability offered by a high-frequency oscillator, the Monolithic Oscillator offers the same general advantages as other silicon components – the most significant, of course, is that, unlike standard escapement components, it’s completely unaffected by magnetism. The Monolithic Oscillator seems to be a solution, too, to the most divisive quality of the Defy Lab’s oscillator, which is its sheer size. The size isn’t so much a problem if you’re looking for visual drama but it does limit the degree to which the technology can find its way into a larger range of watches. If the Defy Lab was a proof-of-concept, the Monolithic Oscillator is a demonstration that flexible silicon oscillators need not be a niche product – at least, there are no insurmountable technical barriers. The Monolithic Oscillator even manages to deliver a very respectable 80-hour power reserve.
The greatest difference between the Monolithic Oscillator and the Zenith Oscillator is size. The Zenith Oscillator took up the entire diameter of the case, more or less; the Monolithic Oscillator, on the other hand, was developed in order to make the basic flexible oscillator technology fit into the space normally occupied by the conventional escapement, balance, and balance spring. Doing so helps keep the watches at a friendly size for daily wear, as the Monolithic Oscillator uses much less space – the Monolithic Manufacture is a very wearable 40mm in diameter, vs. 44mm for the slightly larger Zenith.

Another advantage to the one-piece silicon oscillator is a reduction in parts count. The oscillator has just three components – the oscillator itself, and the two adjustable weights. These replace, in a conventional watch, the balance, balance staff, balance spring, collet (which attaches the inner coil of the balance spring to the balance), balance stud (the fixing point of the outer coil), the four jewels in the antishock system, two antishock springs, and the lever, lever pivot and lever jewels … as well as, come to think of it, the two jewels for the lever pivots as well. You also don’t have to worry about oil deteriorating on the balance pivots or on the escape wheel teeth, which is a ubiquitous cause of long-term rate variation in a standard Swiss lever watch.
The fact that the oscillator has been significantly downsized also means more conventional aesthetics, which depending on your tastes may be a feature or a bug. The Zenith is a large, extroverted showcase for high-tech component manufacturing and it’s an extremely distracting watch to wear. I mean that in a good way – the high-speed vibration of the oscillator is mesmerizing to watch, albeit unsettling in its velocity. The Monolithic Oscillator, on the other hand, vibrates so quickly that it looks almost as if it’s standing still, and the reduced size means less visual impact as well. What you get back, though, is a watch capable of presenting its high-tech heart in a traditional package.
The watch is a limited edition in two different case materials. Steel models with a blue or white dial are $4,795, with 810 of each slated for production; the gold model is $15,995, in an edition of 81 watches. Pricing for the steel models, especially, reflects Frederique Constant’s longtime basic approach to watchmaking, which is to provide classic design at a relatively affordable price (while at the same time offering as much technically distinctive watchmaking as possible).
It’ll be interesting to see how customers react to this watch – it’s obviously an attempt to bring flexible silicon component technology more into the mainstream, perhaps more than would be possible with the Defy Lab. The latter is an intentionally tech-forward watch intended to put the new oscillator front and center. The Monolithic Manufacture, on the other hand, wants to offer the same advantages but in a more conventional package (and therefore one which, FC hopes, may have a broader appeal).
I remember in the early 2000s, when silicon components began to find their way more and more into conventional watches, how much hand-wringing there was amongst us grouchy traditionalists. The thought of, say, a Patek, with a silicon balance spring, raised my hackles in a big way, as it seemed completely inconsistent with the traditional craft, traditional materials approach to mechanical horology that I’ve always cherished. Nowadays, though, silicon has long since become an established part of watch technology, with silicon balance springs, levers, and escape wheels almost ubiquitous.

There’s no denying that in a lot of respects, silicon components offer advantages over conventional ones. In a conventional movement, the setting of jewels into the movement, adjustment of the pallet stones on the lever, poising (dynamic and static) of the balance, forming and pinning the balance spring, and so on, are all intrinsic elements of traditional watchmaking craft. Anything that threatens to replace them outright kind of gives me the willies. What I like about the approach to the material in the Monolithic Manufacture (and in the Defy Lab) is that they take advantage of properties silicon has that can’t be duplicated in conventional materials, to create something you can’t make using standard brass, steel, rubies, and oil.
Although there have been any number of experimental, concept, semi-experimental, and limited-edition watches with silicon components, the material’s aesthetic possibilities remain relatively unexplored. Here I run into some mixed feelings about the Monolithic Manufacture from a design standpoint. I generally don’t care for openings in the dial of a watch – there aren’t too many tourbillons, for instance, with open dials that no matter how good, I wouldn’t like even better if they just closed that dial up. However, the rationale for having an open dial on the Monolithic Manufacture is the same as for an open-dial tourbillon – if you want your watch to be a conversation piece, it’s nice to not have to take it off and peer through a display back to get the conversation started. I’d be curious to see how the oscillator, with its slick peacock-blue sheen, looks in a less conventionally turned-out timepiece. I like guilloché and pomme hands and Roman numerals as much as the next person, but the oscillator’s so high tech you kind of get the same feeling you’d get if a UFO landed at the Louvre.

The Frederique Constant Slimline Monolithic Manufacture is, if not immediately seductive, still a fascinating step in the evolution of silicon components. It would seem to have solved most if not all of the problems potentially raised by monobloc silicon oscillating systems, offering a great power reserve, and a smoothly gliding hour hand reminiscent of Spring Drive, or even a classic tuning fork Accutron. This should be an ideal system for a sports watch – low mass, high shock resistance, inherently antimagnetic, good rate stability – and it will be interesting to see if, after the production run of the Monolithic Manufacture is sold out, Frederique Constant sticks with it and deploys it more widely in its other collections.