Vintage Grand Seiko & Credor: The God of Adjustment

KIH · 2013-03-11T18:48:08Z

Explore vintage Grand Seiko 5722B, 4420, 61GS VFA, and a rare Credor Chronometer. Discover the 'god of adjustment' and his pursuit of extreme accuracy.

KIH

WPS member · Horological Meandering forum

27 replies5129 views0 photos

KIH shares an intimate encounter with a renowned watchmaker, affectionately dubbed the "god of adjustment," showcasing his personal collection of meticulously adjusted Grand Seiko and Credor timepieces. This post highlights the extraordinary precision achievable in vintage mechanical watches and offers a rare glimpse into the dedication required to push horological accuracy to its limits.

He brought some of his nice collection of his (which of course he has done adjusting himself or he will in time).... I would want any of what he has adjusted.....

Please read also the interview of this "god" here:
interviews.watchprosite.com

Sorry for the not-so-good pic quality as the room was so dark!

Grand Seiko the second - 5722B - his daily wear these days.
More accurate than those sold today for sure

NOS 4420 GS - he is about to start servicing and adjusting.

The 61GS VFA which he adjusted - he says that this is the best result he could bring to the vintage GS. Thanks to the very good base design of the movement itself. "More accurate than the normal quartz watch" according to him

The next to VFA is also very little known gem - the ONLY Chronometer of non-GS brand. As I mentioned in my interview with him, this is what he did before he officially started to work on the accuracy of the modern GS mechanical watches in 98. YG/WD version was sold as LE of 500 in 97 and this WG/BD was made for a particular watch retailer with LE of 30 or so..... And there is COSC paper! I am sure he re-adjusted it to the much higher standard - but he admitted he couldn't do it as good as for VFA. VFA seems that good, even today's GS standard.

A bit boring back side - too much bridge covering almost everything. SEIKO does this because they simply can. Their parts precision is that high....

Very unique hair spring structure: a small weight glued to the hair spring to control the position difference. More on this later (hopefully...). Street watchmakers tend to take it away thinking it is just a dust and create a mess for this wonderful rare chronometer movement.... sigh....

Watches of the night....

Wonderful line-up by the adjustemnt proficient. Fun time passes so quick. Hope to meet again when he got a new "toy" to play with.

Thank you, Mr. Ohira! Hope to see you again soon.

Best,
Ken

This message has been edited by KIH on 2013-03-11 18:56:50

Key Points from the Discussion

The level of timing and positional rate delta achieved by Mr. Ohira, particularly the ability to time a mechanical watch with such precision across six positions, is considered an extraordinary feat beyond most watchmakers' skills.
There is significant interest in the principle of weighting a hairspring, with speculation that it functions similarly to an overcoil in controlling poising errors from the hairspring's expansion and contraction.
The duration a finely tuned movement retains its accuracy is a key question, with the understanding that while adjustments can last as long as normal servicing intervals, factors like mainspring life can affect long-term performance.
Mr. Ohira is now a senior trainer for Grand Seiko's global customer service facilities, indicating that the design of VFA movements, though 40+ years old, was made with exceptional precision and durability.
While current Grand Seiko watches can be adjusted to the same high level of accuracy as vintage VFA models, the time required for such meticulous adjustment means it's not feasible for standard production, which adheres to a 6-position standard.
The Credor watch is particularly admired for its gorgeous aesthetics, and there's a mention of another non-GS Seiko chronometer, the 6246-9000, which also achieved chronometer certification.

The Discussion

Ophiuchus

Mar 11, 2013

Would very much like to hear a conversation with Mr. Ohira on the principle of weighting a hairspring. I assume it is to function much like an overcoil in its intended effect- controling poising errors from the hairspring's expansion and contraction in a controlled manner. Also, what kinds of average rate and positional rate delta in timing is Mr. Ohira capable of achieving (seconds per day/positional rate deviation)?

KIH

Mar 11, 2013

.. and will get back to you hopefully soon. As for the accuracy, the VFA is right now less than 1 second per day in any position as well as daily wearing usage. Ken

sidneyc

Mar 11, 2013

God of adjustment truly deserve the name!

Dr No

Mar 11, 2013

. . . of Mr Ohira is how long a tuned movement will retain its timing before drifting off. Understandably, there isn't a hard and fast answer, but one wonders how long adjustments last on average before he has to take screwdrivers in hand again. Sorta like adjusting the bias on output tubes of some power amps . . .

SALMANPK

Mar 12, 2013

I love to see these Vintage beauties and your Credor...I am in Deep Serious Love with it :-) Do you have more pics of the NOS 4420 GS? Thanks for Sharing :-) S

KIH

Mar 12, 2013

I am interested, too. My VFA has been doing great for several months already. He has done more than several for his own and I will ask him next time I meet him. But my guess is that is the matter of the parts life. If the main spring is dead, it would be beyond his control and he just needs to replace it, for example. As for just the adjustment, as long as the parts works as it is supposed to, then the duration of its accuracy should be the same as the normal servicing interval. Just my guess an

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