Grand Seiko 9SA5 mehanizam

**mihajlons** · 30.3.2022., 7:26

Nisam nasao nigde na forumu temu pa da otvorim ovde. 2020 godine Grand Seiko je lansirao novi mehanizam koji je dobija dovoljno prostora da se o njemu prica iako to zasluzuje. Najnoviji i revolucionarni mehanizam, kako kazu, koristi novi izum “dual-impulse escapement” koji nudi nesto potpuno novo nakon co-axial. Iako je Grand Seiko vec izbacio spring-drive i mislilo se da ce se tu stati, ipak su nastavili da pomeraju granice u izradi mehanickih satova.

Sam mehanizam ima 80 sati rezerve (twin-barrel), 36000vph.

Uveliko se ugradjuje u SLGH modele

https://www.grand-seiko.com/global-e...echanical/9sa5

https://youtu.be/m5KTcMzFpBY

https://youtu.be/BUbJvRFHqoQ

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**Haifisch23** · 30.3.2022., 12:42

Mihajlo,

9SA5 je revolucionaran za Grand Seiko, dok je za industriju daleko od ikakve revolucionarnosti. Zato moramo biti pažljivi kada upotrebljavamo izraz revolucija.
Nezavisni časovničar Reuben Schoots je analizirao ovaj mehanizam i ovo su najbitniji delovi:

The new Dual Impulse Escapement impulses the balance in each direction of oscillation of the balance; directly to the balance in one direction and via the lever in the opposite direction, much like George Daniels’ Co-Axial Escapement. However, the “devil is in the details”! If we take a closer look at how the escape wheel delivers impulse to the balance in Daniels’ Co-Axial Escapement, we see that it is via a pushing action with increasing friction as the impulse proceeds, as does Grand Seiko’s Dual Impulse Escapement.
If we, however, compare the way in which impulse is delivered to the lever, via the escape wheel, we find that the Co-Axial Escapement does this as a pushing action, with minimal friction, thanks to its secondary (Co-Axial) wheel and very clever lever jewel configuration. The same cannot be said for the Dual Impulse Escapement, as it still relies on a sliding action to deliver impulse to the lever, and thus, the escapement will suffer from (albeit to a lesser extent, as this sliding friction has now effectively been halved) the same erratic timekeeping as observed with the Lever Escapement, as the lubrication deteriorates. Point 2 then, Impulse delivered tangentially with minimum friction, has been addressed in this new escapement, but it has not been solved. The escapement is, however, thanks to its increase in efficiency, a major contributor to the massive 80-hour power reserve that Grand Seiko have achieved in this 36,000 vph movement.
Grand Seiko opted for an overcoil-type balance spring and have done away with their traditional regulator; this necessitates the inclusion of recessed timing screws on their all-new and most beautiful four armed balance wheels. The exclusion of the traditional regulator, combined with the overcoil and new balance wheel is a setup that is typically found in high-end precision timekeepers from Switzerland.

A new movement architecture, with double barrels in series, all new and very attractive movement bridges, the first time we see a balance bridge from Grand Seiko, made with the watchmaker in mind, with adjustable height for easy endshake adjustment for the balance pivots. Grand Seiko have also managed to reduce the overall movement thickness by 15 per cent, thanks to a new horizontal wheel train layout.

Ovaj kalibar ima dodirne tačke sa čuvenim Seiko Magic Leverom, kojeg su posudili od Aleberta Pellatona (IWC) odnosno njegovog dvosmernog načina navijanja mehanizma poznatog kao Pellaton sistem. Kod 9SA5 su se oslanjali na Danielsov Co-Axial, kojeg su naravno kao i Magic Lever priredlili na svoj način. Najveća promena je u promeni vlastitog regulatora i prelazak na takozvani Free Sprung, kojeg je najbolje razvio Rolex.
Naravno, ništa loše, 9SA5 je odličan i vrlo lep industrijsko oblikovan mehanizam. Svakako predstavlja veliku promenu za Grand Seiko i neko novo usmerenje ali ga ne možemo smatrati revoulucionarnim u opštem smislu.

**mihajlons** · 30.3.2022., 12:58

Drago mi je da si ponovo aktivan i ukljucio se u diskusiju. Upotrebio sam rec revolucionaran jer ga je GS tako predstavio mada mi je bilo nelogicno s obzirom na nacin na koji im funkcionise ovaj escapement, revolucionarniji mi je spring drive. Vec su strucnjaci objasnili da mehanizam nije toliko pomerio granice koliko to GS predstavlja. Al moras priznati da je pohvalno sto GS ulaze u razvoj i pokusava da uradi nesto novo makar to bilo slicno sa necim prethodnim. Ne rade robotizovano ili klasican copy-paste vec zaista se na napretku radi. Da zanemarimo klasican proizvodni program nh35. I sam izgled mehanizma je ocaravajuci.

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**Haifisch23** · 30.3.2022., 16:02

Nisam nigde kritikovao ovaj mehanizam. Baš suprotno. Ne znam više gde ali sam ga već pominjao na forumu u vrlo pozitivnom svetlu. Meni lično najveće dostignuće GS do sada.

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