Patek Philippe Central Rotor Automatic Movement History

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AndCavanaugh's meticulous analysis of Patek Philippe's central rotor automatic movements provides an invaluable historical and technical resource for collectors. This deep dive into the evolution of calibers 310, 315, 324, and 26-330 illuminates the brand's continuous pursuit of horological refinement. Understanding these generational shifts is crucial for appreciating the intricate engineering behind some of Patek Philippe's most iconic timepieces.

In the late 70s Patek was juggling four automatic movements: 240, 28-355 (JLC 920), 27-460, and 350. They wanted a thin, automatic movement with sweep seconds that wasn’t the 350. Eventually this movement family, and the 240, would replace the other three and is still going today. Unlike the 240, this movement family has had extensive changes across four generations. There is some bleedover between generations, and differences within generations, so take none of this as gospel.

310 (and 335)

1980ish

The first generation was caliber 310, a unidirectional (clockwise) automatic movement with indirect sweep seconds and date that was 26 mm in diameter while being only 3.15 mm thick. These movements used an off-the-shelf assortment with a generic balance, Trivolis, Incabloc, flat hairspring, and 4hz beat rate. They did not carry the Geneva seal.

310’s date wheel was flush with the movement, but too broad for the smaller dials of the Nautilus collection. Patek created caliber 335, which uses a narrower date wheel which sits on top of the movement, at the cost of an increased height (3.45 mm). A quickset for the date was added a few years later.

315 (and 330)

1990ish

310’s automatic winding system was unreliable and inefficient. Patek reworked the automatic winding system in its successor caliber, 315, which now winds counterclockwise. Once again there would be a variant with narrower date wheel, the 330. This time Patek graced 315/330 with a gyromax balance, Geneva stud, KIF, and Geneva seal, as well as lowering the beat rate to 21,600 bph.

Unlike its predecessor, 315 would act as a base for complications, including Patek’s retrograde perpetual and annual calendars. The complicated versions would have some features of the next generation. All three generations of complicated movements have the bridge side barrel arbor jeweled. There was also an advanced research version of 315 with silicon escapement and balance spring.

324

2004

For the third generation Patek increased the beat rate to 28,800 with the new 2-spoke-4-weights gyromax balance (these can also be found on later 315s). Eventually on these movements would all get silicon Spiromax hairsprings. The rotor grew 0.1 mm in diameter and 0.08 mm in height, the hand winding system was beefed up, and tooth-profiles for the going and date trains were changed to make power transmission more uniform (per Patek’s press release for the 5135). The dial side bridge is now two separate parts, but I’ve noticed this was already present on complicated 315s. Also they switched back to Incbloc.

Dandong (major movement manufacturer in Liaoning) allegedly makes a 324 “clone” for use in high quality “replica” watches. These copy the basic design of caliber 324, but parts are not interchangeable with genuine ones. I wrote a mini post on Atelier Wen’s use of a sterile version here.

26-330

2019

The winding system was redesigned for a third time. Previously the pinion by the rotor would move laterally, decoupling from the winding train when the rotor turns clockwise, and recouping to wind the barrel when the rotor turns counterclockwise to wind the watch. 26-330 instead uses a pair of pawl wheels (one by the rotor and one by the barrel). This system (and the new rotor shape) was soft launched on the 5520 (cal. 30-660) alarm travel time a few years back. It also uses a new rotor mount which debuted on the cal. 28-520 all the way back in 2006.

Since these movements have indirect seconds they used a friction spring, like you see on chronograph seconds hands. With the fourth generation this was replaced by a special LIGA etched third wheel which grips the sweep seconds pinion. Once again, this has been used for chronograph seconds hands by Rolex and Patek. Also it hacks now. All of these changes are explained well in this video.

About the Patek Philippe Ref. 5135

The Patek Philippe Reference 5135 represents a masterful interpretation of the annual calendar complication, introduced as part of Patek Philippe s contemporary collection following the brand s pioneering work in accessible perpetual calendar alternatives. This reference showcases Patek Philippe s commitment to horological excellence while maintaining the practical sophistication that defines their modern complicated timepieces. The 5135 carries forward the prestigious legacy of Patek Philippe s calendar watches, offering collectors a refined example of Swiss haute horlogerie that balances technical complexity with everyday wearability.

At the heart of the Reference 5135 beats the automatic Caliber 324 S QA LU, a sophisticated movement that displays the annual calendar function with exceptional precision and reliability. This self-winding caliber incorporates Patek Philippe s advanced gear train technology and maintains the brand s stringent finishing standards throughout its construction. The movement elegantly orchestrates the display of day, date, month, and moon phases, requiring adjustment only once per year at the end of February. The 38.2mm rose gold case provides optimal proportions for this complex movement while ensuring the various calendar indications remain clearly legible on the pristine white dial.

The design philosophy of the 5135 emphasizes classical elegance through its clean white dial presentation, which serves as the perfect canvas for the multiple calendar apertures and subsidiary dials. The fixed bezel and sapphire crystal construction reflect Patek Philippe s commitment to durability and optical clarity, while the overall aesthetic maintains the timeless sophistication expected from Geneva s most prestigious manufacture. For collectors, the Reference 5135 occupies a significant position as an accessible entry point into Patek Philippe s complicated watch segment, offering the prestige of annual calendar functionality in a format that exemplifies the brand s design philosophy and technical mastery.

Specifications

Caliber: Cal.324 S QA LU

Case: Rose gold

Diameter: 38.2mm

Dial: white

Water Resist.: 30m

Crystal: Sapphire

Key Points from the Discussion

The base Caliber 310 was specifically utilized in several Calatrava models featuring narrow bezels, with the primary differences between the 310 and 335 being the hour wheel, minute bridge, date wheel, and the presence of two riser plates on the dial side of the 335.
While Dandong's SL-4530 movement has nearly all parts interchangeable with genuine Rolex 4130 components, their 324 'clones' offer limited interchangeability, possibly only for the date wheel and rotor, despite following the same basic design.
The very visible LIGA-etched third wheel on the Patek Philippe Caliber 26-330 is likely an effective anti-counterfeiting measure, whether intentionally designed as such or not.
The discussion highlights the importance of understanding the supply chain within the watch industry, particularly regarding movement manufacturers like Dandong, which also supplies brands such as Atelier Wen.
The detailed breakdown of Patek Philippe's movement evolution is praised for its thoroughness, offering a 'merciless' level of detail for a manufacturer considered a pillar of watchmaking.

The Discussion

gary_g

Dec 27, 2024

I’m amazed how thin the movements were 40 years ago. Thank you for sharing.

piccolochimico (aka dsgalaxy1)

Dec 27, 2024

Your analysis is as detailed as merciless for a movement and a manufacturer that represent the pillar of watchmaking. Well done, waiting for your next topic

patrick_y

Dec 28, 2024

I'm fairly familiar with the 315, 324, and 330 movements. But didn't know much about the 310! Thank you for this! And give us more details about the Chinese clones of the 324!!! And feel free to mention that Dadan supplies Atelier Wen! I don't mind. We're not trying to disparage anyone. We're just trying to add some clarity to this opaque industry and how this industry is supplied!

AndCavanaugh

Dec 28, 2024

The base 310 was used in a few Calatravas with narrow bezels. The only difference afaik between the 310 and 335 are the hour wheel, minute bridge, date wheel, and the 335 has two riser plates on the dial side. On Dandong’s infamous SL-4530, nearly all parts (including balance complete) are interchangeable with real Rolex 4130 parts. That isn’t the case for their 324 clones, maybe the date wheel and rotor are interchangeable but that’s probably it. It does follow the same basic design as the 324

GLau

Dec 28, 2024

Well done ! Did you spend much time on the research ?

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