ABTW: What was the most difficult part of development of the Spring Drive?
YN: It was the energy balance issue: the balance between generation of electricity and its consumption by the Integrated Circuit. The result was that, in the early prototypes, the watch did not run for long enough to be viable. The amount of electrical power generated was not enough and the consumption of electricity by the Integrated Circuit was too great.
ABTW: Our understanding is that the value of the Spring Drive movement is in both accuracy and autonomy. As a watchmaker, comment on these claims and help people new to Spring Drive understand what that means.
YN: Like a mechanical watch, Spring Drive is powered only by mainspring but, unlike all mechanical watches, it delivers accuracy of +/- 1 second a day, plus a power reserve of 72 hours. This is the appeal of Spring Drive. It offers the autonomy of a mechanical watch and the precision of electronics; it is the best of both worlds.
In addition, it has a unique visual signature. The perfect smooth movement of the hands lets the wearer experience the natural and continuous flow of time without any ‘tick’ and this perfectly expresses the Japanese sense of time. Time flows elegantly and silently in Spring Drive. We hope that more and more people will feel the beauty of Spring Drive.
ABTW: How long does it take to assemble a Spring Drive timepiece and how many constituent parts are involved?
YN: On average, a craftsman can assemble 8-10 regular Spring Drive movements (9R6 series) a day. The number of component parts of a 9R6 movement is about 240. As for the Spring Drive Chronograph (9R8 series), 2-3 movements a day can be made and there are around 400 components.
ABTW: Is there anything about the Spring Drive you believe could be improved upon?
YN: As a mechanism, I would say ‘no’. However, as a complete watch, my answer is definitely ‘yes’. Spring Drive is a platform on which we can build many types of watches and there are also many design possibilities to explore. Personally, I hope that we can create more luxury watches with Spring Drive. The Micro Artist Studio is a small team now and it creates special watches that bring high-level Japanese craftsmanship to Spring Drive. I hope our team becomes larger so that we can create more true luxury watches for the world.
ABTW: If a watchmaker aspired to join your elite team of watchmakers at The Micro Artist Studio, what skills would you suggest they focus on?
YN: The Micro Artist Studio is a group of experts in different fields of watchmaking which include engineering design, machining process, hand polishing, quality certification, and assembling. In the Studio, wide and deep knowledge is needed in each of these fields.
To answer as for my field, assembling, a craftsman must be capable of casing and repairing. Aside from these skills needed for assembling, he or she must be able to repair and adjust the tools, to handle machine processing, to understand the drawings and to understand and imagine the mechanism in your head, which also contributes to find and correct any imperfections. All these abilities are important.
Other specific skills are needed as well, like parts polishing, parts size control and adjustment, parts finishing, and adjustment in assembling to tolerances of 1/100mm. These specific skills can be best obtained on the job. As for complication watches like the Spring Drive Sonnerie, one can only master its assembling after real assembling and disassembling. Experience is the key to enhancing skill. Only with experience and with the patience to go through many ‘trial and error’ processes can someone become a true craftsman.
ABTW: Could you tell us a little more about the special skills and talents necessary to work on these movements?
YN: The skill to assemble luxury watches is essential.
To be able to handle the parts properly and assemble them without scratches, specific knowledge and techniques for the quality control such as the amount of torque for screwing or amount of lubricant are necessary. Experience in assembling a wide range of movements is also needed to be certain that each movement is perfect.
The assembling of Spring Drive movements is done mainly by the craftsmen and women who are qualified as the 1st grade of the national certification. We have an internal qualification system for the skills needed for assembling, which corresponds to the national certification. Personally, I think the most important thing is to be serious about what you do and pay attention to every detail.
ABTW: What watch do you wear personally, Mr. Nakazawa?
YN: At present, I wear a Seiko Brightz radio-controlled solar watch that is marketed only in Japan.
This watch is made of titanium so it is very light and robust and the dial is with Arabic numerals which are very easy to read. It is very easy to use and I can wear it without any care.
I used to wear often a Credor Spring Drive watch and Grand Seiko 9F quartz watch. I gave them to my sons who now love to wear them. I hope they pass the watches to my grandchildren.
Again, a special thanks to Mr. Yoshifusa Nakazawa for participating in this aBlogtoWatch interview.