Caveman's Watch Forum

Update! Pulsar PU2005 and musings on MécaQuartz in general

Ricky Lee

January 05, 2012 08:00PM
Registered: April 2005
Posts: 17,866 (2012-03)

I'm afraid that I did the SII VK63 / Seiko 6T63 a disservice in my review of 12 December 2011. Basically, I dismissed it as an "utterly conventional quartz movement", only with "instant chrono reset". Well, not quite true. Oops!

I confess that I hadn't done much hardly any research, and had some half-baked ideas about what a "MécaQuartz" should be. In my naiveté, I expected that the chrono would be powered by a conventional mainspring. Blushing Sort of a chrono version of the Fossil Twist, I guess.

Anyway, after I'd stuck the ol' foot in me mouth, then I did a spot of research on "MécaQuartz". My favorite definition of the term is from Stephen Sugiyama's web site, and goes in part like this:

Stephen Sugiyama

Mecaquartz chronographs use movements of a hybrid construction. These movements join a quartz-regulated electronic timekeeping engine and a mechanical chronograph module. ...

Quartz watches with an "analog" display use a small stepper motor to drive the watch hands. Mecaquartz movements use a second, separate stepper motor to drive the chronograph module. A gear-train translates the motor drive into movement of the chronograph hands.

The chronograph motor operates at a higher frequency than the one-tick-per-second of the timekeeping motor. This gives the chronograph a smoother sweep and allows the measurement of intervals with greater precision than full seconds. The reset lever operates on a heart-shaped cam so reset is mechanical and instantaneous.

By way of contrast, a conventional quartz chronograph uses separate motors to drive each counter on the dial. ...

Aha! Now it becomes clear. A "MécaQuartz", rather than driving each chrono hand with its own separate stepper motor, drives all of them with a single stepper motor via a mechanical geartrain. No mainspring required! Smile

From there it was a small step to find that the premier MécaQuartz movements are generally considered to be the pioneering Jaeger-LeCoultre calibre 630 series and the Piguet calibre 1270 series. The former is much more common that the latter, and is also seen bearing the IWC brand. I have thus far been unable to find much hard technical documentation on the JLC, but if you run this search you'll find quite a lot of reading material. I do know that it has 222 mechanical parts, 25 jewels, and is a mere 3.7mm in height. I'm not sure of the ligne size, but JLC has used the movement in watches as small as 34mm.

To find a photo of a JLC calibre 631, we need look no further than our fearless leader, Reto Castellazzi. Wink

Photo by Reto

Indeed, Reto owns several MécaQuartz chronos, too...

Which brings us back to the Seiko 6T63 / SII VK63. Smile

While the amount of "hard technical documentation" I've found is limited, I can say a few things with confidence. The movement does qualify as a true MécaQuartz, as the central chrono seconds and chrono minutes totalizer are driven by a single stepper motor via a geartrain. A second stepper motor drives hours, minutes, running seconds, and 24-hour indicator. A single crystal oscillator is used, running at the usual frequency of 32,768 Hz. The chrono uses a single reset hammer, very similar (if not identical) to the ones used on Seiko's high-end mechanical chronographs.

And then there's this..

Stock photo

..nice exploded view, which was extracted from the Seiko Technical Guide.

Referring back the the JLC/IWC 631 for a moment, one thing Reto said intrigued me:

Reto favorite feature while traveling. If you change the time zone, just start the chronograph, then change the time - hacking the time will not stop the chronograph second - and after finish setting the new time zone, simply synchronize the seconds. I am traveling quite a bit and I really love to have the possibility to keep the seconds as I had set them before the trip.

This got me to wondering if the VK63 is capable in this area, too, and I discovered that you can indeed reset the main time while the chrono is running. I shouldn't have been surprised as, had I been paying attention Blushing, Seiko themselves point out on page 6 of the 6T63 User Instruction Manual:


1. When the stopwatch is or has been measuring, if the crown is pulled out to the second click, the stopwatch will continue the current measurement.


Now, I hesitate to mention it, but it is also possible to reset the chrono without first stopping it. If you depress the bottom pusher with the chrono running, it snaps back to zero and stops. Disclaimer: I have no idea if this is safe, and am not recommending it as S.O.P.! If you do this and destroy your 6T63 / VK63 I will not be held responsible! And, really, there's no reason to do it. If you can't take the time to stop the chrono before you reset it, you should buy flyback chrono, or perhaps a Rattrapante. Smile

So. All in all I'm still happy as can be with the Pulsar and the VK63! Besides the "instant reset", the MécaQuartz design also offers potential benefits in battery life and.. well, dang it! It's just cool! Rolling on the floor laughing my a.. off

Edit; 2012-01-09 addendum: A couple of folks have opined via eMail that another benefit of a MécaQuartz is lower production cost, via elimination of at least one, and potentially two stepper motors. In short, I'm unconvinced. My gut feeling (and, as a manufacturing professional, my educated guess) is that the cost saved by deleting the extra stepper motors is more than offset by the addition of the chrono geartrain. That being said, the 6T63 / VK63 obviously is a cost-effective movement. The fact that it can be had in a full SS Pulsar version for a street price of less than US $100 proves that. And, yes, 'tis worthy of note that this is the polar opposite of the manufacturing and marketing paradigm that the Swiss MécaQuartz movements in question adhere to.

Pulsar World Rally chronograph

Thanks for readin', y'all.



Messages In This Thread

Update! Pulsar PU2005 and musings on MécaQuartz in general Jpeg Attachments URL PDF Attachments

Ricky Lee 530 January 05, 2012 08:00PM

Thanks! I learned something smile (n/t)

Ed Brandwein 27 January 06, 2012 06:36AM

That was very interesting , Ricky! Never seen those before! Wis-dom!Cheers!Thumbs up! (n/t)

IF 26 January 06, 2012 01:54AM

Cool! This makes me wonder about something. Are all the Seiko>>>

quartz chronos that beat faster than once per second of the mecaquartz variety?
DJM 30 January 06, 2012 12:48AM

Re: ..quartz chronos that beat faster than once per second of the mecaquartz variety?

No, definitely not.

The 7T32 and 7T62 use four separate and discrete stepper motors. As does the 7T92.

Not sure about the rest.. I'd have to research it. Smile However, to the best of my knowledge, the 6T63 / VK63 is the first Seiko-Epson movement that could properly be termed a MécaQuartz.
Ricky Lee 40 January 06, 2012 06:40AM

Thank you! smile (n/t)

DJM 18 January 06, 2012 09:01AM

I am confused Very interesting! smile Also, just to play it safe, I think you should get a Rattrapante! laughing (n/t)

Nuvolari 28 January 05, 2012 11:02PM

I think so, too! Thumbs up!

I'll add it to The List before I turn in tonight.

I promise. Innocent

Rolling on the floor laughing my a.. off
Ricky Lee 22 January 06, 2012 06:47PM

Thanks for the clarification SmileThumbs up! (n/t)

Need_Omega 30 January 05, 2012 08:52PM

Least I could do...

Blushing Wink
Ricky Lee 28 January 05, 2012 09:30PM

Strap swaparoo at Tom Swift's Watch Shoppe

January 13, 2012 02:11PM

As I've mentioned about a half-dozen times in the Rollcall Threads, I changed this one from the OEM leather to a black G10 NATO solely for to facilitate dual-wristing.

Yeah, I finally took photos!

Pulsar World Rally chronograph
Click HERE for larger photo or HERE for supersized photo

I wear nylon only on the right wrist, you see...

Pulsar World Rally chronograph
Click HERE for larger photo or HERE for supersized photo

Still lovin' this Méca-Quartz beauty! WIS Honeymoon

Pulsar World Rally chronograph
Click HERE for larger photo or HERE for Watch or Accessory Review

It wears Grrrrrrrrrrrrrrrrrrrrrrrr8! on the NATO! Cool Thumbs up!



"A watch should be worth looking at even when you already know the time" - vintage Omega ad

Messages In This Thread

Strap swaparoo at Tom Swift's Watch Shoppe Jpeg Attachments URL

Ricky Lee 111 January 13, 2012 02:11PM

Pretty P. Wink (n/t)

James T. Kirk© 23 January 14, 2012 01:43PM

I think this one looks better on the Nato. Does it have a20hr. chrono? (n/t)

Timemiser 27 January 14, 2012 08:25AM

No, the 6T63 / VK63 is a one-hour chrono.

* Subdial at 3 = 24-hour indicator slaved to main time

* Subdial at 6 = running seconds (1 Hz)

* Subdial at 9 = minutes totalizer, 60 minutes capacity
Ricky Lee 46 January 14, 2012 10:56AM

Ok. Thanks I should have known that. That is the same movt. as mine. Jpeg Attachments

Photo by Timemiser
Timemiser 29 January 14, 2012 04:51PM

I wasn't gonna rub it in...

..nor post a "Doh!" or nothin' like that...

Innocent Rolling on the floor laughing my a.. off
Ricky Lee 31 January 14, 2012 06:03PM

Cool!Cheers! (n/t)

IF 16 January 14, 2012 02:52AM

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