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seiko 7015 stops when changing day


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Hello dear watchmakers. 

Last week, I was lucky enough to get my self a beautiful vintage Seiko chronograph watch with 7015 movement.

The overall condition looked great so I did not expect any problem with the watch.

However, over the last few days, I noticed that this watch stops around 1~2am when the day disk moves to the next day. 

At first, I thought there was no residual power in the mainspring but the watch won't start after being shaken for some time.

It runs well and keeps good timing after I move the day disk manually by adjusting hands by crown till the next night around 1 am.

Could you please give me any ideas on this issue?? I really love this watch and want to make this watch perfectly functional. Thank you.

I put some photo of the watch and what timegrapher tells 

KakaoTalk_20180808_093502745.jpg

KakaoTalk_20180808_093504527.jpg

KakaoTalk_20181005_104418381.jpg

Seiko_7015A-1.jpg

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thw date uses energy from the trainwheels. energy that is usually used to push the balance jewel and increase the amplitude. 

if you got too much friction in the date mechanism, there is none left for the balance

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Just my two cents as I don't know your Seiko; as Matabog says above. To investigate you have to get to the date mechanism, removing hands and the dial. If the date mechanism is driven from the hour-wheel, remove the hour wheel and observe the movement during the date-change period. If it keeps running happily, you excluded the wheel train and can zoom in on the date mechanism; trouble shooting by elimination.

Check the amplitude again, as it doesn't seem high. It could also be that a part of the keyless works runs too heavy. Removing the hour-wheel may give you more information.

A combination of the keyless, date-change and low amplitude may cause the watch to stop.

When was the last service?

Edited by Endeavor
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31 minutes ago, Endeavor said:

Just my two cents as I don't know your Seiko; as Matabog says above. To investigate you have to get to the date mechanism, removing hands and the dial. If the date mechanism is driven from the hour-wheel, remove the hour wheel and observe the movement during the date-change period. If it keeps running happily, you excluded the wheel train and can zoom in on the date mechanism; trouble shooting by elimination.

Check the amplitude again, as it doesn't seem high. It could also be that a part of the keyless works runs too heavy. Removing the hour-wheel may give you more information.

A combination of the keyless, date-change and low amplitude may cause the watch to stop.

When was the last service?

 

Hello. I am not sure when it was last serviced and I haven't opened it yet. I will try testing the movement in the way as you wrote. Thank you for considerate advice!

Edited by east3rn
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1 hour ago, matabog said:

thw date uses energy from the trainwheels. energy that is usually used to push the balance jewel and increase the amplitude. 

if you got too much friction in the date mechanism, there is none left for the balance

Hello.  I will open up the watch and see what happens. Thank you for  your considerate advice!

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A lot has to do with friction. Provided the main spring gives it's "normal" power, the power is used to drive the wheel train, to drive the escape mechanism, to drive the hands, the intermediate wheels of the keyless and the date-mechanism. Any one of those can cause the watch to stop. But if over time the overall friction increases (wear / oil) you can get to a point that when power is needed to change the date & day, the combination of the overall friction and the additional power required to change these two may become just too much for the spring-power to overcome. At first glance that seem to be the case, as your watch seems to run "fine" when that additional power is not required.

If the amplitude of your watch is around 215 degrees well before or well after the date- & day-change, that seems to me too low. Either the main-spring has weakened, the wheel-train runs too heavy or a combination of the two. When with an amplitude of 215 degrees the date-mechanism requires the additional power, that may be enough to stop the watch.

So, your watch, mechanically speaking, may be just fine. After a full service, a proper inspection and a new main-spring installed, the amplitude should be much higher and the watch may thereafter run perfectly.

If the watch, after a proper service still has problems, you need to dig deeper. For now, my advice would be, don't go trouble shooting as the watch may be just "fine". All what it needs may be just a proper service.

 

 

Edited by Endeavor
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You say,  once you manually change the date " it runs til next night".

Dose it run for twelve or twenty four hours?

Either case poor power can hardly be considered as the culprit. Rather the day change train. Plus date plate warpage or any faulty contact at anypoint thereabout.

Regards

 

 

 

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On 10/5/2018 at 12:25 AM, Nucejoe said:

Either case poor power can hardly be considered as the culprit. Rather the day change train

One of the problems with the time graph for results is we see that the dial is facing up. The problem with timing results the dial up and dial down position is resting on the end of the pivots which is the least friction. So we like to see one of these.we also need a case wristwatch crown down. I am guessing that amplitude of 214° that crown down the amplitude drops considerably which tells us this watch desperately need servicing.

Then anything beyond this without removing the hands and dial to observe is basically guessing.

On 10/4/2018 at 7:22 PM, east3rn said:

At first, I thought there was no residual power in the mainspring but the watch won't start after being shaken for some time.

I find this is an interesting sentence? When you have to shake the watch a lot to get at the start it sounds like a watch that is totally wound down. If it's a watch that is in desperate need of servicing then this is also what you're describing. So I was thinking an experiment about one hour maybe two hours before it comes to a stop put it back on the timing machine. Both dial-up like you did before and crown down let's see what the amplitude is at the end of 24 hours. That's the give us a clue of what's going on then beyond that they hands and dial have to come off.

 

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I was thinking about this discussion and when I woke up this morning I had some ideas? So link below so we can see all the variations as I was looking for a 7015 tech sheet and all I could find which I'm attaching is a 7016 which should be equivalent more or less. The reason for that is if you've never done a Seiko chronograph you really should have the tech sheet.

Then not mentioned in the old tech sheets is how do you know if your watches fully wound up? So for that I'm going to a newer tech sheet which is the NE15C this is equivalent to the Seiko 6R15. So for the ratchet wheel screw you turn it eight turns. Then for the crown as you can manually wind this watch it's 55 turns. But nowhere does it say how many times you have to shake it to wind it up?

So conveniently I have a Seiko 7002A in front of me. Putting a dot on the ratchet wheel at roughly 50 shakes it rotates one half turn. So that would say roughly 800 shakes should you get you close to being Fully wound up.

The other things we Learn in the NE15C tech sheet is they time in three positions. Which is dial-up, 9 o'clock up which is equivalent to crown down and 6 o'clock up.

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Seiko_7015A

Seiko 7016A.pdf

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