In this focus #4 We delve into the inner workings and mechanisms that power the Orion series. With a second hand moving at a rate of 4 beats per second and a lunar disk advancing 6.1 degrees every 1,440 minutes, the SW288 embodies Swiss watchmaking expertise.
- ORIGIN OF CALIBER SW288
An improvement by Sellita of the ETA 2800
Founded in 1950 in La Chaux-de-Fonds, Sellita has established itself as a key player in the Swiss watch industry, renowned for the reliability and accessibility of its movements. For several decades, the manufacturer mainly assembled calibers for ETA, before this collaboration ended when in 2003 Swatch Group decided to restrict the distribution of its movements to third parties.
Once seen as a subcontractor, this situation has pushed Sellita to develop its own calibers, often inspired by ETA models, while integrating improvements. Its ability to offer reliable alternatives to ETA movements, while also innovating, has redefined the balance of power in the sector.
The scarcity of ETA calibers offered Sellita a unique opportunity . The growing demand for alternative movements allowed Sellita to assert itself as an essential solution by producing derivative movements and innovating with specific watchmaking complications.
Despite its initial outsider status, Sellita has gained recognition for the quality and competitiveness of its calibers, particularly among new brands and independent watchmakers. The SW288-1 caliber, with its central moon phase complication, is a typical example of this success.
The SW200 family symbolises Sellita's new positioning : building on a proven ETA technical base, making modifications such as the addition of additional jewels to improve the longevity and robustness of the movements.
The SW288-1 in particular perfectly illustrates this rise in power and testifies to Sellita's growing role in a market undergoing rapid transformation. It is particularly distinguished by its moon phase complication with a large central aperture. A rare feature that has no direct equivalent at ETA .
- CALIBER FINISHES
Decoration of factories
Sellita offers four levels of finishing for its calibers, classified from D1 to D4. Each level reflects a growing commitment to aesthetics and technical perfection, allowing watchmakers to choose the configuration best suited to their models.
D1: Without decoration The D1 level represents the standard version of the movement. Here, priority is given to functionality, with a lightly decorated finish. Traces of machining and handling may still be visible, and its use is recommended only for closed case backs.
D2: Simple Decor From the D2 level, decorative elements begin to be added. This level includes polished components and a spiral paper finish (decorative finish with a concentric spiral pattern). The D2 aims to balance aesthetics and functionality, suitable for models looking for a slight visual extra.
D3: Careful decoration The D3 level introduces more pronounced finishes, such as engravings, optional Côtes de Genève or pearl patterns on the plate and bridges. The decorations become more apparent, and key components can benefit from treatments such as rhodium plating, providing metallic hues while increasing resistance to corrosion.
D4: Luxurious decor
The D4 level, chosen for the Orion series , represents the pinnacle of the manufactures’ expertise. This degree includes a circular-grained plate decorated with a circular pattern that reinforces the movement’s structure and overall aesthetics. Components such as the crown wheel, ratchet and barrel are enhanced by a snail finish , a technique that creates concentric spiral patterns.
The movement screws , treated at high temperatures, acquire a characteristic bluish hue , a symbol of traditional know-how. In addition, sophisticated surface treatments, such as rhodium plating, gilding and ruthenium anthracite , are applied to offer a palette of metallic and colored hues while protecting the components from corrosion and wear. This attention to detail ensures not only a refined aesthetic but also increased durability of the movement .
- DECORATION OF BRIDGES
Inspired by the solar panels of the Orion spacecraft
For the series’ bridges, we worked closely with Sellita to develop a bespoke finish that was faithful to the spirit of this collection. The motifs on the three bridges – barrel, gear train and escapement – are inspired by the Orion’s solar panels and are integrated. The aim was to integrate design elements from the ship, while maintaining aesthetic consistency with the rest of the calibre.
The bridges are made of anthracite ruthenium, a material selected for its robustness and dark hue. The bevels are also treated in anthracite, creating a subtle contrast with the rest of the caliber. This treatment not only reinforces the solidity of the bridges, but also provides a marked visual effect. The pattern is then engraved to add depth and a refined aesthetic dimension. Finally, an unengraved band surrounds each bridge to preserve the integrity of the engraving and ensure a smooth transition with the anthracite finish.
- CALIBER ADJUSTMENT
Developed at +/- 7 sec / day
Caliber adjustment consists of adjusting the precision of its mechanical movement by modifying various parameters, such as the spring tension, the amplitude of the balance wheel and the regularity of the escapement. This process is done in several stages, generally in different positions to simulate real conditions of use. Sellita calibers offer different types of adjustments that are classified into four categories: Standard, Elaboré, Top and Chronometer.
The STANDARD adjustment is made in two positions, with an accuracy of +/- 12 seconds per day. The ELABORE adjustment is made in three positions, allowing for better accuracy with a margin of +/- 7 seconds per day. The caliber features high-quality components, such as an escape wheel and anchors that are polished and treated with an epilamé coating.
The TOP setting is performed on five positions, with a stricter precision of +/- 4 seconds per day. Finally, the CHRONOMETER setting is a certified version of the Top setting. In fact, it must pass the tests of the COSC (Swiss Official Chronometer Testing Institute), which checks the precision of the movement to -4/+6 seconds per day.
For the Orion series, we have chosen the elaborate adjustment , offering an excellent level of precision and reliability. This choice also guarantees good resistance over time thanks to quality components, such as the Incabloc system.
The switch to the Top setting would have resulted in a price increase of around CHF 110, which we wanted to avoid in order to keep the price affordable. However, in response to your requests, we are currently discussing with our assembler, PH Saner, to make this setting available as an option.
We hope that this article has helped you better understand our design choices as well as all the subtleties of the SW288 caliber, soon to be brought to life on your wrists.
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