The latest trends in the movement as generations change (Part 2)

Only by improving performance without significantly changing the diameter or thickness of the movement can it be called normal evolution. In particular, achieving a long power reserve of three days as standard is now considered essential for a practical watch. The main focus of development was to review the escapement shape, reduce its weight, and optimize the barrel shape.

Read more about the latest trends in the movement as generations change (Part 1)
http://www.webchronos.net/features/42508/
Read from "The Latest Movement as Generational Change Advances (Part 2)"
http://www.webchronos.net/features/42530/

The art of maturing the next-generation core movement

　If you want to quickly improve the performance of a movement, increasing the diameter is an extremely effective method. However, since increasing the size of the movement essentially means making the watch itself oversized, it is undoubtedly a double-edged sword. Maintaining an appropriate size is an absolute requirement for true, normal evolution. In other words, the key to design is how to pack high performance into the same space as the previous generation watch.

ROLEX Cal.3235
First released in 2015, this newly designed movement replaces the 27-year-old Cal. 3135. Approximately 90% of the parts are newly designed, and 14 new patents have been filed. It features the Chronergy escapement, which improves escapement efficiency through a change in tooth profile and weight reduction. The 31 series and 32 series also feature the reversed direction of the hands relative to the crown. Diameter: 28.5mm, thickness: 5.37mm. 31 jewels. 28,800 vph. Power reserve: approximately 70 hours (according to editorial department).

ROLEX Cal.3135
First released in 1988. A very thick, practical movement, rare for its time. Produced from the 1960s to the early 1980s, the free-sprung version was introduced with the Cal. 1570, followed by the 30 series, which adopted the Microstella screw system. The Cal. 3135 also adopted the Microstella nut system. The ruby-colored reverser is also a detail carried over from the 15 series. Diameter: 28.5mm, thickness: 5.37mm. 31 jewels. 28,800 vph. Power reserve: approximately 48 hours (according to editorial department).

　One brand that has consistently challenged this normal evolution head-on is Rolex. The company doesn't release the detailed dimensions of its movements, so it's difficult to say for sure, but as far as I can tell, the basic size of 12 lignes hasn't changed at all since the 1000 series (Caliber 1030, first released in 1954), which was the first to feature a bidirectional winding rotor. The latest in this lineage is the Caliber 3235 (hereafter referred to as the 32 series), which was introduced in 2015. Considering that the previous model, the Caliber 3135 (31 series), was first released in 1988, this is the first generational change in 27 years.

　While some of the technologies used in the 32 series, such as the blue Parachrom hairspring, which offers excellent shock and magnetic resistance, were introduced in later models of the 31 series starting around 2005, Rolex acquired 14 new patents for the caliber 3235. In fact, the 32 series is a completely new movement, with less than 10% of parts shared with the 31 series. The power reserve was particularly significant. The 31 series' power reserve was approximately 48 hours, which was standard at the time, but this was dramatically extended to approximately 70 hours for the 32 series. Given the practical nature of Rolex watches, a watch needs a power reserve of at least three days to continue performing at its best on Monday after being left idle for two days over the weekend.

The monoblock rotor is sintered and mounted on a ball bearing. The ruby-colored reverser, made of lightweight, hardened aluminum, is an open type for the 32 series, further improving winding efficiency.

The blue Parachrom hairspring is made of niobium, zirconium, and hafnium. It has excellent shock resilience, magnetic resistance, and temperature resistance. The balance wheel's Microstella nut adjusts the speed.

The Chronergy escapement was first installed in the 32 series. By reducing weight and revising the tooth profile, it achieved an efficiency increase of approximately 15% compared to the Swiss lever escapement. It is made from a paramagnetic nickel-phosphorus alloy.

Since 2010, the shock-resistant device for Rolex movements has been changed from KIF to Paraflex shock absorbers. There is no distinction between the front and back, and the center of the hole jewel is held in place by a frame, making it resistant to deformation.

　This "3-day" specification is a prerequisite for a modern core movement. Rolex has expanded the internal volume by thinning the barrel wall without changing the barrel diameter, allowing for a longer mainspring than before. However, this alone does not achieve a full day's power reserve, but only an extension of about 10 hours.

　Another key feature is the Chronergy escapement, which achieves approximately 15% greater efficiency than the Swiss lever escapement. The key to this improvement is the nickel-phosphorus alloy escape wheel, which has been lightened through a redesigned and thinner anchor and micro-machining using the LIGA process (including skeletonization). The aforementioned Parachrom (an alloy primarily consisting of niobium, zirconium, and hafnium) hairspring, along with the nickel-phosphorus escapement, also contribute significantly to improved magnetic resistance. Both materials are inherently magnetic, meaning their metallic properties are less susceptible to change even when exposed to strong magnetic fields. Minor changes include a sintered monoblock rotor serving as a bearing support, and the adjuster on the double-supported balance bridge, which adjusts the vertical movement of the balance, has been reduced from two to one.

　While Rolex has redesigned roughly 90% of its basic structure, Patek Philippe has refined its existing movements to deliver high performance. The Caliber 26-330 SCJ SE, announced by the company in 2019, is the legitimate successor to the Caliber 324 SC, which debuted in 04. Its roots can be traced back to the 1991 Caliber 315 SC. Following a series of refinements, including the 315/190, which changed the number of teeth on the winding wheel, and the 315/290, which increased the torque of the mainspring, the movement was given the new number 324 in 04, when it was made to have a higher frequency (8 vph) (since 06, it has been equipped with a Spiromax silicon balance spring).

　The Calatrava Weekly Calendar, which first featured the 26-330, features a semi-instantaneous 53-circle calendar module, hence the sub-number at the end, but what is noteworthy is the base movement. In addition to the SPYR movement adopted in the 315/290, which was first released in 03, the new 26-330 actively incorporates anti-backlash gears made by LIGA molding, further stabilizing the movement of the hands.

　Originally, the 315-324 series movements had both the second and fourth wheels offset, and the third wheel drove the second pinion, creating a center second hand. Therefore, a second pinion regulating spring (a leaf spring made of beryllium copper) was essential to stabilize the movement of the second hand. By using an anti-backlash gear on the third wheel, which virtually eliminates backlash by forming each tooth tip into a spring shape, it became possible for the first time to omit the second hand regulating spring, which is prone to wear. This is also used in the winding wheel of traditional unidirectional winding rotors, and similarly eliminates backlash during idling. A reduction gear was also added to the manual winding mechanism, further enhancing safety. Another user-friendly improvement is the addition of a stop-seconds function, which is a welcome addition.

　The same can be said for the "Caliber 925/2" announced by Jaeger-LeCoultre in 19, which features a long power reserve for the core movement and enhanced safety by omitting the second hand regulation spring. This was also first equipped with the "Master Ultra Thin Moon Enamel," so it has the 925 number, which indicates that it is equipped with a moon phase module, but in reality it should be called a modified version of the base model, the "Caliber 899."

　Caliber 899 is a high-beat movement released in 2005 as a free-sprung version of the Caliber 889 series developed in 1983. At the same time, the rotor support bearing was changed to a ceramic ball bearing developed in collaboration with MPS. The new 899 series has an extended power reserve of approximately 70 hours, and the second pinion has been changed to an anti-backlash gear similar to Patek Philippe.

　There's a reason why both companies started using this gear at almost the same time. The technology was originally developed by module supplier AgenEse, and was known among some enthusiasts as the "AgenEse gear" (officially known as AgenEse). However, the company's president, Jean-Marc Wiederrecht, declared it patent-free through the International Chronometer Society in 2016, as a shared asset that would improve the performance of the entire Swiss watch industry. About three years have passed since then, and the results of this declaration are beginning to spread.

　What's remarkable about the 899 Modification is its long power reserve. While the old 899 had a power reserve of approximately 38 hours, the new 899 Modification boasts a power reserve of approximately 70 hours. While the aforementioned Rolex increased its power reserve by approximately 50%, Jaeger-LeCoultre, based on the slim 899, has achieved a power reserve increase of nearly 85%. The switch to a lightweight silicon escape wheel/pallet fork contributes to an increase of approximately 10 hours. The remaining approximately 20 hours are entirely due to structural changes to the barrel. Specifically, the long power reserve is achieved by increasing the height of the mainspring, rather than increasing its length. Stéphane Belmont, the company's technical director and marketing director, states, "By removing something that was inside the barrel, we were able to increase the volume without changing the outer diameter." The actual technique is an adaptation of an old technique, and he was intrigued to try it out.

　The most notable example of a movement with minimal changes to its size yet still achieving incredible performance improvements is the Caliber 3861, released by Omega in 2019. It was based on the Caliber 1861, which debuted around 1996. Its origins can be traced back to the Caliber 861, released in 1968. Mechanically, there are not many differences between the 861 and the 1861, so this is essentially a full renewal after a gap of roughly half a century. While it remains in its first year of release and is still only featured in limited editions, Omega expects to completely replace the 1861 in the near future. According to Gregory Kisling, who led the development, the primary goal of the 3861 was to create a Master Chronometer—a manual-wound chronograph that could withstand magnetic fields of 15,000 gauss.

The idler bridge of Cal. 3861 is properly chamfered, and the finish is more refined than that of Cal. 1861. The pivots on both the normal and accumulating gear trains have been replaced with Nivagauss.

The idler wheel and bridge of the Caliber 1861. Unlike the original Caliber 861, this part is not chamfered. Incidentally, the chamfering here is also a distinguishing feature between the early and late models of the Caliber 910 for the Flight Master.

　The biggest change is the addition of a silicon balance spring and a three-stage Co-Axial escapement. However, since it was intended for use in the Moonwatch, a supplier to NASA, the watch's specifications could not be altered. This meant that a Co-Axial escapement (and a modern three-stage version, not a simplified two-stage escapement) had to be installed on a platform designed by Lemania more than 50 years ago. Surprisingly, this was accomplished without any problems. The adoption of a free-sprung mechanism to accommodate the silicon balance spring likely offset the height of the regulator. Furthermore, the 3861 expands the balance wheel diameter to the very edge of the baseplate and nearly doubles its thickness. Furthermore, the barrel arbor has been narrowed to accommodate a more powerful balance spring. Furthermore, the synergistic effects of a new tooth profile for the standard gear train, which improves transmission efficiency, have increased the balance wheel's moment of inertia from 13 mg/cm2 in the 1861 to 24 mg/cm2. This is one of the highest specifications among current chronographs. This is the true power of a modern core movement that has been replaced with cutting-edge inner parts.