Advice please. Accuracy after $1300 service. Valjoux 7751

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Sarbie
Posts: 196
Joined: Tue Oct 03, 2017 6:23 pm
Location: AK

Sun Oct 22, 2017 4:34 pm

Stevo_iwc wrote:I’d be OK with those results but then accuracy is something that interests me but seldom concerns (me unless it is significant enough to indicate a fault). As Don mentioned grade movement is important and if the movement is a standard valjoux then those results are ok. Having said that it could be regulated further if it concerns you.


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Sweet thanks Stevo. I am as largely concerned after the tests. I would be happier if the face down and face up results were inverted because to self regulate I have to leave my watch upside down.

I also would be happier if my watch was slightly fast rather than slow.

I guess my original concern was that I was getting everything I paid all that money for.

Still I may give them a call and discuss it with them. They really did seem reasonable and it may be out of their desired accuracy.

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the gold bracelet thing was my dads necklace he gave me before he died...but i dont like things round ma neck
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Sarbie
Posts: 196
Joined: Tue Oct 03, 2017 6:23 pm
Location: AK

Mon Oct 23, 2017 7:01 am

I managed to find some information in an online manual this morning.

I replaced the specific watch brand when mentioned with (brand), so as not to come up in google searches for the service centre etc.
If you would like to know the model of watch please PM me. Cheers guys.

The precision of a mechanical movement depends on the individualhabits of the wearer and can therefore vary. A qualified (brand) watchmaker can adjust the precision of a watch to within the (brand) tolerances, which are from -1 to +6 seconds per day.Other (brand) mechanical watchesWatches without chronometer certification (COSC) have averageprecision tolerances of between -1 and +11 seconds per day.The precision of a mechanical movement depends on the individualhabits of the wearer and can therefore vary. A qualified (brand) watchmaker can adjust the precision of a watch to within the (brand) tolerances.
the gold bracelet thing was my dads necklace he gave me before he died...but i dont like things round ma neck
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Don
Posts: 881
Joined: Thu Aug 27, 2009 11:22 pm
Location: Auckland

Mon Oct 23, 2017 10:36 am

Sarbie wrote:
Sun Oct 22, 2017 12:26 pm
...

Each measurement was 12 hours so needs to be doubled for a full day result.

Face up test was done 3 times because the first measurement was out of whack compared to the rest, my feeling is that the watch was not wound first and possibly made a difference.


12 Hour test

Crown up.............-6 seconds
Crown down.........-5 seconds
Face up...............-12 seconds (possibly less wound)
Face up...............-6 seconds
Face up...............-7 seconds
Face down............+5 seconds
Face down............+6 seconds (re tested due to the + anomaly)
Wearing................-5 seconds
12 up...................-6 seconds
12 down................-6 seconds

if all results are doubled the arrived accuracy is -14/+12 seconds per day if -12 second anomaly is removed.
...
Great to see that you've completed your test, and apology for the delay in responding--thanks for the PM btw. It's a good learning experience indeed, and gives one a new perspective on accuracy and precision. The next time you read on watch forums "mine runs x sec/per day" or "one week of wear and it's only x seconds off", you'll realize these statements don't mean much without the supporting test figures. Also, the next time that you run timing test like this, around 6 hours per position should be enough, which would mean you should be able to time it in four positions from full-wound state without significant impact from isochronous error. After 24 hours have lapsed, you can fully wind the movement again to take one or two more position.

The important thing to stress here is to ensure, as best as you can, that the main spring is fully-wound. This means at least 40-50 turns of the crown from unwound state, or until you feel a significant increase in tension. You don't need to worry about over-winding on this one, as this won't happen on an automatic self-winding movement, only manual-wind ones. The Valjoux 775x, in particular, needs more of your help in getting sufficient power reserve, due to the fact that the winding rotor only winds in one direction, and therefore less efficient than, say, your Seiko automatics.

Also crucial is to ensure you calculate the rate correctly, e.g. if after 6hr 23m (6.3833 hrs) has passed and the difference is 3 seconds, then the rate is (24 x 3)/6.3833 = 11 sec/day, after rounding off.

Looking at the figures that you've obtained, the current average daily rate is approximately -8 sec/day, and on-wrist -10 sec/day, meaning that by wearing this watch, you make it lose an additional -2 sec/day. The latter is your personal error. The result of your test would look okay for a used yet-to-be-serviced watch, but IMO, outside of spec for one that has just been serviced. Especially of concern is the positional error on the Dial-Down position, for which you have tested twice.

Sarbie wrote:
Sun Oct 22, 2017 12:26 pm
..."The precision of a mechanical movement depends on the individualhabits of the wearer and can therefore vary. A qualified (brand) watchmaker can adjust the precision of a watch to within the (brand) tolerances, which are from -1 to +6 seconds per day.Other (brand) mechanical watchesWatches without chronometer certification (COSC) have averageprecision tolerances of between -1 and +11 seconds per day.The precision of a mechanical movement depends on the individualhabits of the wearer and can therefore vary. A qualified (brand) watchmaker can adjust the precision of a watch to within the (brand) tolerances."
This is more like a disclaimer-type inclusion by the manufacturer, so can't go on this much. :)

Sarbie wrote:
Sun Oct 22, 2017 12:26 pm
...
I guess my original concern was that I was getting everything I paid all that money for.
...
The short (and painfully brutal, sorry) answer to this is "no". :| ...but that's one of the reasons that we have a forum like this, and it's part of the learning process. So, please do embrace and appreciate it as it happens to many of us :) ...I remember when I first started in watches, I too paid hundreds of dollars for a battery change and pressure-test on a high-end brand (despite its ETA-based quartz movement), through a so-called "authorized service center".

All just because I thought, at the time, that the watch was 1) more complicated to work on than it actually was, 2) authorized SC somehow knew more than regular experienced watchmaker, and 3) authorized SC could order special parts that other watchmakers couldn't. All of these, of course, proved to be a bunch of BS that I got sold in addition to the price tag on that watch, and after learning more about watches, thanks in large parts to the honest watchmakers that I've had the pleasure of knowing over the last couple of decades, none are true. I did, however, pay for my earlier misconceptions, just as a lot of us here have.

For me to say that $1,300 for an overhaul of a ETA/Valjoux 7751 is anywhere near reasonable would be an insult to the many skilled, experience, and honest watchmakers in New Zealand. It would be saying that other respected watchmakers who charge far less are somehow less able/qualified than the authorized SC, for which the opposite is often true. But this, too, is part of learning process.

Sarbie wrote:
Sun Oct 22, 2017 12:26 pm
...
Still I may give them a call and discuss it with them. They really did seem reasonable and it may be out of their desired accuracy.
...
In my view, you can certainly get this matter rectified to your satisfaction, and perhaps better now than later when it can look like the fault is of your own doing. If feasible, go to the service center in person, be firm (play a bit of "bad cop"?), and speak to the watchmaker, not just the receptionist or whoever attends the counter. Let the watchmaker know that you have ran tests (CU -12, CD -10, CL -12, CR -12, DU -12, DD +10), and point to him/her the positional error.

If you can, demand that they show you right there and then the watch on their vibrograph. It is a 30 seconds job to open the back and mount it on a vibrograph. It is not complicated nor time-consuming. You'll see the reading as the watchmaker shifts between different positions. The result may differ from yours, and you may have made some errors in your tests (we actually hope that is the case), but that is the only way to know. As you the watch is being timed in different positions, you don't actually need to know a lot about watches--just observing the expression on the watchmaker's face should tell you more about what would be the next course of action.

Let us know how it goes. :)
Don
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Sarbie
Posts: 196
Joined: Tue Oct 03, 2017 6:23 pm
Location: AK

Mon Oct 23, 2017 11:02 am

Thanks Don.

I will follow this up this week and post any outcomes.

thanks TKNZ too.
the gold bracelet thing was my dads necklace he gave me before he died...but i dont like things round ma neck
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