The cliché: Sometimes you have to break some rules to achieve what you want. This is the case in Greubel Forsey Double Single Balancier Constant Différentiel, because it sacrifices some basic principles-between the elephants, and the good legibility of 3, 4 and 10 points-which helps to highlight some complex mentalities, incredible and eye-catching. Wateringly beautiful mechanical feat. This is how and why.
Founded in 2004, Greubel Forsey has created some of the most complex tourbillon watches ever made in the horology world, thus earning itself a reputation—think Quadruple Tourbillon (do it here), or a value of US$2 million Watch Art Piece 1 (hands-on). The very successful collaboration between Robert Greubel and Stephen Forsey for about 12 years (and continues) has proven to be enough to allow some non-tourbillon creations to enter the brand’s category to drive down the price to a more affordable level. Although this still means that we are going deep into the six-figure field, it actually enables GF to interact with high-complexity products from major brands such as Jaeger-LeCoultre, Audemars Piguet, and a long list of others.
In typical Greubel Forsey fashion, this means not including traditional complications, such as perpetual calendars (although they have done one of them, and it’s very incredible), chronographs or repeaters, but using twists , Enhanced and complex change timing mechanism. In Greubel Forsey double Balancierà Différentiel constant, its fancy forward-looking and -sounding, as the name suggests, are not one but two balance wheels, with the attack and concentration difference added by the sphere.
Let us first take a look at this pair of crazy ticking balance wheels and uncover the mystery. As they say, “If one is good, then two are better”, but this is clearly only the tip of the technical iceberg. The two balance wheels are arranged on two independent escapement platforms, each of which is composed of 71 parts. These platforms have been tilted and installed, and each of them is at a 30° angle to the plane of the sports board.
The reason is as follows: the performance (velocity and amplitude) of the balance wheel and hairspring is strongly influenced by their location. When the watchmaker adjusts the movement, he/she must find the right balance between the two. Sports performance in different positions is quite different. When the watch is lying flat on the table—so the wheels and springs are also horizontal—the rate will be very different from the rate when you place the crown down, so they are almost in a vertical position.
By installing the balance wheel and its platform at an angle to the main board and each other, each balance wheel will spend a very limited time in the horizontal and vertical positions (even if the watch is placed on a table or vertically in a safe), where the difference and The biggest error. The 30° angle of inclination can be used as a constant average coefficient, and since the two balance wheels are set at different angles, at least one of them will always be closer to the ideal state.
The question now is how to convert the speed difference between the two balance wheels into mechanical timekeeping-how to make the two timekeeping mechanisms drive only one set of hands? The answer is the differential, a system very similar to the system in a car. Frankly speaking, since I obviously don’t have the in-depth understanding of this mechanism like its creator, please bear with me like I did, but try to give you an overview of how it works and why it was there in the first place. . But first, please watch this sweet old video, which beautifully explains how the differential works-take 5 minutes to learn about it, and then be taken aback.
If you look at the close-up picture above, you will find that, in essence, the differential consists of three wheels stacked on top of each other. The top and bottom ones are connected to each of the two escapements, while the middle one is connected to the walking gear train, or basically the rest of the movement. Now, as the balance wheel is ticking at its own speed-ideally 3 Hz or 21,600 vibrations per hour, none of them will run exactly at that frequency due to deviations caused by position errors-the differential, Use the principle explained in the video above and take the average of the two.
So, for example, if one escapement runs at -2 seconds per day and the other runs at +2, the average value of the differential transmitted to the hands is actually 0 – or perfect timing. So what does the 0-1-2-3 sub-dial have to do with these? That is a four-minute counter, connected to the other part of the differential…
You see, it seems that all the dizzying engineering is not enough. Greubel Forsey adds a constant force mechanism to the differential. Through a small hole on the side of the bottom cover of the movement, a wheel and a spring on the underside of the differential can be seen. This spring may look a bit like a balance spring to an untrained person, it is responsible for releasing its energy into the differential, all the way to the double escapement. This is done to counteract the weakening of the torque transmitted by the movement’s two main barrels in series at the end of the 72-hour power reserve. The four-minute counter we mentioned above is associated with this bottom gear of the constant force mechanism, because it takes four full minutes to complete a complete rotation.
With all this in mind, let us sit down, take a deep breath, and take a look at Greubel Forsey Double Balancier à Différentiel Constant from further afield. It is here that those obsessed with legibility (those who think that a watch is a watch, regardless of price or complexity, and therefore must be able to tell the time effectively) will find that Koppelforth breaks the perfect rule of legibility. There is no other way: half of the dial is missing, so it would be very challenging to tell the time at a glance, half of the day, between 4 o’clock and 10 o’clock. But is this really that big?
Based on my experience with the Greubel Forsey double balancer À Différentiel Constant, I tend to (see what I did there?) to say: no. Although the long and well-proportioned hour and minute hands have large Super-LumiNova-coated tips at the ends, their polished silver middle part blends into the movement area, causing legibility problems. But—it’s a round, full-bodied but—after careful observation, even the most determined supporter of legibility will find that the rewards they receive are worth every sacrifice.
After all, in addition to sheer complexity, the excellent surface finish quality makes Cooper Fuss almost no competitors: they know the greatness of traditional decoration techniques, and their team of watchmakers has indeed pushed these techniques to their limits. . Huge black mirror-polished areas, bevels on the panels and hand-polished “angled” edges, even screw heads, polished countersunk heads, polished and beveled splints for fixing the balance wheel… all these are in the context of manual applications Glittering frost finish.
Every part on the front and back has been really carefully polished and decorated-there may be other aspects of the polish of the watch movement, and the technical options for different surfaces may be different, but frankly speaking, things have not become more refined And among all the 285 parts of the GF04 manual winding movement, they are more pleasing to the eye. discount watch
The 18k white gold engraved folding clasp that matches the metal of the 43 mm wide and 13.38 mm thick case has a cherry color on the top. It looks and works like an over-designed lock on an old vault door, and it does a good job of securing a very heavy but still very beautiful watch to the wrist.
Obviously, the Greubel Forsey Double Balancier à Différentiel Constant watch has more details that need to be carefully studied-such as a gray PVD treated main board, a fast-rotating barrel, or a neat add-on like a “hand-stamped” back plate. . Movement or helical gears and special-shaped teeth on the fourth wheel. The list is endless, but Greubel Forsey Double Balancier à Différentiel Constant shows it the moment you wear it on your wrist: it displays more than 200 carefully crafted watch components in front of you-two balance wheels tick at the same time Xiang left at the speed he wanted. cheapest watches