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Moose

7S26C Date misaligned

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Hello All.

Just given a stripdown/clean/service on a Seiko SKX007 (7S26C) and after reassembly all is fine and regulated to an acceptable level for the calibre. It has to be mentioned that I am an "ethusiast" watch fettler and by no means experienced.  My background is my "Hello" post in the introductions page.

I have noticed that the date is misaligned after it self-changes date after midnight. Day and date setting by hand works fine, but after midnight, the date seems to "over rotate" leading to a slight misalignment in the date window (see photo).

When I noticed this, I removed the hands and dial again, as well as took apart all of the date wheels and corrector mechanisms and carefully reassembled it all. The date jumper spring is properly engaged/lubricated and the date driving wheel seems to be doing its job correctly, when observed with the dial off. But, as can be seen, the misalignment is still present after it changes by itself.

Can anyone offer any advice as to what may be causing the issue?

 

IMG_1454.jpg

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Was it aligned before the service or is this re-build. I have had this a happen when refurbishing a watch. It was the new date ring (which was after market part) was incorrect. I had to fit another date ring which was used but worked correctly. 

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Is it okay with the dial of. Try to lift it slightly and see if it pops in place. If you change the date with the dial of and loose put the dial on . Is it okay then? Is it the original movement? As some new movements has 3 a clock date disc. 

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55 minutes ago, clockboy said:

Was it aligned before the service or is this re-build. I have had this a happen when refurbishing a watch. It was the new date ring (which was after market part) was incorrect. I had to fit another date ring which was used but worked correctly. 

Yes, it was fine beforehand. The repair was for an erratic manual advancing day/date - sometimes it world work for a few turns of the crown and then stop. It turned out to be a broken tooth on the plastic day-date corrector wheel. But that was the only part replaced.

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18 minutes ago, rogart63 said:

Is it okay with the dial of. Try to lift it slightly and see if it pops in place. If you change the date with the dial of and loose put the dial on . Is it okay then? Is it the original movement? As some new movements has 3 a clock date disc. 

I will have to strip it again when I have time on Friday. I am wearing it at the moment to at least prove the basic timekeeping is accurate after servicing. The good news it is keeping very good time, so at least the strip down and clean/re-lube did the job. But I think you are right, I'll have to strip out the date works again, check and reassemble once more and see if anything can be seen.

I can sort of understand if it were under-rotating the date dial as it might be stiff or some dirt in the works. But I'm not sure I understand over-rotating, as it implies that the Date Driving Wheel is staying engaged on the tooth longer than it should.

All parts are original, with the exception of the replaced manual Day-Date Corrector wheel, which had a damaged tooth.

Will report back on Friday, once I have had it in bits again...

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2 hours ago, Moose said:

I will have to strip it again when I have time on Friday. I am wearing it at the moment to at least prove the basic timekeeping is accurate after servicing. The good news it is keeping very good time, so at least the strip down and clean/re-lube did the job. But I think you are right, I'll have to strip out the date works again, check and reassemble once more and see if anything can be seen.

I can sort of understand if it were under-rotating the date dial as it might be stiff or some dirt in the works. But I'm not sure I understand over-rotating, as it implies that the Date Driving Wheel is staying engaged on the tooth longer than it should.

All parts are original, with the exception of the replaced manual Day-Date Corrector wheel, which had a damaged tooth.

Will report back on Friday, once I have had it in bits again...

Check the black date plastic finger. Both that it sits okay and that it's okay. Seen many that has been bent when that white plastic date driving wheel got broken. 

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26 minutes ago, rogart63 said:

Check the black date plastic finger. Both that it sits okay and that it's okay. Seen many that has been bent when that white plastic date driving wheel got broken. 

That’s a good tip, I’ll look at when i strip it again on Friday. Thanks. I do have a spare in a donor 7S26A  movement to compare it with. I’m guessing that this part is the same on the A and C variants.

:)

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20 hours ago, Moose said:

That’s a good tip, I’ll look at when i strip it again on Friday. Thanks. I do have a spare in a donor 7S26A  movement to compare it with. I’m guessing that this part is the same on the A and C variants.

:)

Should be. Think it's the balance and some other parts that are different. I even took the same  date driving wheel from some Seiko quartz movements. That are the same wheel. Don't remember the number now. But i guess they use the same in lots of movements. Check the tiny intermediate wheel to. 

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On 5/29/2019 at 5:36 PM, Moose said:

The good news it is keeping very good time, so at least the strip down and clean/re-lube did the job.

You also need to check with  timegrapher after servicing a movement.

Quote

I do have a spare in a donor 7S26A  movement to compare it with. I’m guessing that this part is the same on the A and C variants.

The day/date advance wheel changes from A to B and C.
One can check my parts table for differences

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

Edited by jdm

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On 5/29/2019 at 10:59 AM, Moose said:

The date jumper spring is properly engaged/lubricated

No lubrication goes on that spring, and in general on any friction point with plastic.

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25 minutes ago, jdm said:

You also need to check with  timegrapher after servicing a movement.

The day/date advance wheel changes from A to B and C.
One can check my parts table for differences

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

OK re the timegrapher. My normal routine is to check the basic working rate with the timegrapher immediately after the repair (just to prove I did not nause it up during the service). Then wear it for a least a day or two, just to make sure the lubricants are all better distributed across the pivots etc. then a final check for beat error (adjusting as may be required), then rate checking across five positions on the timegrapher, trying to get an average of less than 10 secs per day, averaged across all five positions. Also ensuring that the amplitude is also acceptable. 

There you go, maybe a bit of a pedant , but them I’m a hobbyist and also retired, so it’s not like I don’t have the time to waste on trying to keep my work to a high standard.

Good point about the day/date advance wheel though, I will check and compare to ensure I don’t introduce a new problem. Thanks for the interest and your tips.

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40 minutes ago, jdm said:

No lubrication goes on that spring, and in general on any friction point with plastic.

Interesting. I just followed the Seiko instruction sheet for the 7s26c, which shows lubricant added to the edge of the spring that contacts the date wheel teeth. 

Is this not correct?

 

7C447382-5A31-4FFB-AAF7-E89F517A5F82.jpeg

Edited by Moose
Image added.

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3 minutes ago, Moose said:

Interesting. I just followed the Seiko instruction sheet for the 7s26c, which shows grease added to the edge of the spring that contacts the date wheel teeth.

Well, they indicate "Moebius A" that is 9010, not grease to go there. Which makes little sense for a point of slow and (relatively) high friction, and even if it would, why there but not on the day jumper also? However I don't much believe that is the reason of the date being off, which I think is something more trivial.

On the subject of document suggested lubrication.. worth to mention their indication of lubricating the pallet pivots, which is kind of an abomination as it will have the only effect of reducing the already often problematic amplitude of of these Seiko mov.ts.
 

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39 minutes ago, jdm said:

Well, they indicate "Moebius A" that is 9010, not grease to go there. Which makes little sense for a point of slow and (relatively) high friction, and even if it would, why there but not on the day jumper also? However I don't much believe that is the reason of the date being off, which I think is something more trivial.

On the subject of document suggested lubrication.. worth to mention their indication of lubricating the pallet pivots, which is kind of an abomination as it will have the only effect of reducing the already often problematic amplitude of of these Seiko mov.ts.
 

All points noted. I did actually use 9010 and not a grease, slip of the keyboard on my part. As to what to oil and what not, I’m not really in a position to second guess the manufacturer’s official instructions and can have no idea what their intention may have been, when recommending lubricating these points even though my BHI courses also did not include the lubrication of pallet pivots as a general principle.

All the evidence I have, is that this watch was over 10 years old and I was the first person to service it, since it left the factory, presumably lubricated as per the instructions and it was a good timekeeper before the date change corrector broke. So I’ll just follow what they did.

i must admit though, it is a bit confusing that some of the “rules” or “conventions” seem to be challenged here, even with my limited experience. Like lubricating pallet pivots, and some contact parts with plastics, and even putting  lubricant on the teeth of the magic wind wheel, which I sort of know does not sound right - lubricating teeth on a wheel - but I sort of rationalize that by knowing that the actual operation of this part, includes a significant amount of the pawl teeth slipping over the wheel teeth and the resultant friction, which the grease would alleviate.

For sure, there is a lot to keep learning and I hope I can be excused for simply following the manufacturers instructions, in the absence of ages of alternative experience.

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7 minutes ago, Moose said:

since it left the factory, presumably lubricated as per the instructions and it was a good timekeeper before the date change corrector broke. 

I'm doubtful it ever was. Search the internet on the subject "new Seiko lubrication", or do as myself, inspect a brand new mov't. In most case there isn't any where it should be easy to have, e.g. stem, magic lever wheel, etc. In some cases there are traces (or more) of oil left around. However the balance cap jewels always appears to be correctly oiled, most likely by a machine.

7 minutes ago, Moose said:

For sure, there is a lot to keep learning and I hope I can be excused for simply following the manufacturers instructions, in the absence of ages of alternative experience.

Lubrication is a lot about having opinions. Not just because something is printed it has to be right. So we have the technical guides to get an idea, the forum to discuss, and then we use experience and time to tell if it was right.

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