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Overbanking?


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Hi, Just thought I would post this and ask for some help. My Seiko 7006 has been keeping great time and I have been monitoring for a few days. In general the watch is running approx +1 second per day when worn with good amplitude. Last night I went for a brisk walk for an hour or so. During that time the watch gained around 20 seconds. I listened to the watch after shaking for a few seconds and the ticking would race for 1 or 2 seconds before returning to normal. The watch managed to gain another 15 seconds during that testing. I think it is overbanking due to the mainspring not slipping. Just need some pointers to the mainspring lubrication. I have 8217 grease now but need to be careful to add just the correct amount so the slipping is not too much. Could anything else stop the mainspring from slipping at the right time? Thanks in advance. Steve.

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31 minutes ago, steve1811uk said:

I listened to the watch after shaking for a few seconds and the ticking would race for 1 or 2 seconds before returning to normal. The watch managed to gain another 15 seconds during that testing.

That is normal happen if you shake it, mechanical watches are not able to  maintain timekeeping when shaken,  vibrations, exposed to strong magnetic field, an probably other negative external factors. If you need timekeeping in these situation, get a quartz watch.

31 minutes ago, steve1811uk said:

I think it is overbanking due to the mainspring not slipping. 

No. Overbanking happens when the mainspring has been replaced incorrectly with one too strong or banking pins have been messed with - that can't happen with Seiko and other modern watches, as banking pins are cut in the main plate.

You can be reassured that your mainspring is slipping just fine when the watch is fully wound. But even  if  it was not to slip, or slip too early, over banking would not happen anyway. Remember, one can't over-wind an automatic watch, and actually not even a manual one unless forcing further when the crown stops.

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4 minutes ago, jdm said:

That is normal happen if you shake it, mechanical watches are not able to  maintain timekeeping when shaken,  vibrations, exposed to strong magnetic field, an probably other negative external factors. If you need timekeeping in these situation, get a quartz watch.

No. Overbanking happens when the mainspring has been replaced incorrectly with one too strong or banking pins have been messed with - that can't happen with Seiko and other modern watches, as banking pins are cut in the main plate.

You can be reassured that your mainspring is slipping just fine when the watch is fully wound. But even  if  it was not to slip, or slip too early, over banking would not happen anyway. Remember, one can't over-wind an automatic watch, and actually not even a manual one unless forcing further when the crown stops.

I can hear it overbanking for a couple of seconds, like a galloping horse. The watch gained 35 seconds in a couple of hours when it has gained 3 second in 3 days. Something is not right and I think it's the mainspring lubrication that I am going to have another attempt at.

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I think the first place to look is the escapement, usual culprits balance spring dirty or oily causing the coils to stick momenterily and a magnetised movement check for both instances.   Have a look through the loupe the coils should beat cleanly and evenly if they look rough in action then the whole watch will probably need a service and of course new M/s. If the above has been done and the M/s changed, look to the lubrication including the barrel.

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3 minutes ago, watchweasol said:

I think the first place to look is the escapement, usual culprits balance spring dirty or oily causing the coils to stick momenterily and a magnetised movement check for both instances.   Have a look through the loupe the coils should beat cleanly and evenly if they look rough in action then the whole watch will probably need a service and of course new M/s. If the above has been done and the M/s changed, look to the lubrication including the barrel.

Thanks, the watch has been serviced by myself, I just don't think I put enough grease on the barrel wall. Either that or the barrel wall is badly scratched or grooved. I will check it tomorrow and report. Note that the watch has been running great in normal use and has run all today gaining just a second or so since I went to bed last night. It was just the hour long walk that caused the large time gain. My thoughts are that the mainspring got fully wound on the walk and developed too much torque (not slipping properly). Normally my day job consists of sitting at a computer so the spring wouldn't usually get so wound up.

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Do you have a new mainspring in the barrel or you just have the breaking grease to blame. You can't expect good results If you put back in a barrel with scratched up wall, neither.

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It's a common mistake many pros make as well, but it's rebanking. Overbanked is when the safety mechanisms of the escapement are faulty and the fork can cross to the opposing banking at the wrong time, stopping the watch.

If it's rebanking after fully winding it could be too strong of a braking grease. 8217 is considered a soft braking grease, I didn't quite get if you've serviced it and used that, or will service it and use that? If the former, maybe try some Kluber P125? If the latter it could be the grease is hard and useless a and a service will do it.

It's highly unlikely the watch became more efficient through wear, haha.

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8 minutes ago, Nucejoe said:

Do you have a new mainspring in the barrel or you just have the breaking grease to blame. You can't expect good results If you put back in a barrel with scratched up wall, neither.

Mainspring is the one that was fitted, not sure how old it is. I cleaned and refitted by hand using some general grease I had available at the time, probably too thin and watery to be honest. I now have the 8217 and a microscope so will give it another look tomorrow. I just don't want to end up giving it too much slip. It seems that 3 small blobs spread along the barrel wall is the recommended amount.

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12 minutes ago, nickelsilver said:

It's a common mistake many pros make as well, but it's rebanking. Overbanked is when the safety mechanisms of the escapement are faulty and the fork can cross to the opposing banking at the wrong time, stopping the watch.

If it's rebanking after fully winding it could be too strong of a braking grease. 8217 is considered a soft braking grease, I didn't quite get if you've serviced it and used that, or will service it and use that? If the former, maybe try some Kluber P125? If the latter it could be the grease is hard and useless a and a service will do it.

It's highly unlikely the watch became more efficient through wear, haha.

Thanks for the terminology correction. Going to have another go tomorrow with 8217 that I now have in hand. I think the grease I used originally was just not suitable, too thin, too easily displaced and not providing any cushioning and hence no slip.

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1 hour ago, nickelsilver said:

It's a common mistake many pros make as well, but it's rebanking. Overbanked is when the safety mechanisms of the escapement are faulty and the fork can cross to the opposing banking at the wrong time, stopping the watch.

Excellent clarification, thank you.

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If it's rebanking after fully winding it could be too strong of a braking grease

Not for this class of Seiko. Really they are made for the barrel never to be open, but very typically people, mostly total beginners, think to know better and do any kind of manipulation an lubricati9n to the MS, invariably with hand winding. Then the the power delivery may not be perfect, or maybe isn't bad at all, we really don't know, however the mainspring is promptly blamed for being too strong after a good shake when the watch normally keeps excellent time? I see little logic in all that.

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8217 is considered a soft braking grease, I didn't quite get if you've serviced it and used that, or will service it and use that? If the former, maybe try some Kluber P125? 

Upgrade to P125 price £65 + VAT,  for a vintage Seiko 7009 valued possibly less than that, work done by amateur (my same category) not using an instrument that show amplitude and pattern. Hmm...

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2 minutes ago, jdm said:

Excellent clarification, thank you.

Not for this class of Seiko. Really they are made for the barrel never to be open, but very typically people, mostly total beginners, think to know better and do any kind of manipulation an lubricati9n to the MS, invariably with hand winding. Then the the power delivery may not be perfect, or maybe isn't bad at all,we don't know really if that, but the mainspring is promptly blamed for being too strong after a good shake when ithe watch normally keeps excellent time? I see little logic in all that.

Upgrade to P125 price £65 + VAT,  for amvintage Seiko 7009 value possibly less than that, work done by amateur (my same category) not using an instrument that show amplitude and pattern. Hmm...

Not very helpful, even the professionals were amateurs when they started. I am using logic and my ears to come to the conclusion that the watch is rebanking due to poor mainspring lubrication. Just after some advice on the correct amount of grease to use. I do have a 1900 Timegrapher at my disposal that shows amplitude over 320 degrees when the rebanking noise has just stopped. Also how logical is it for Seiko to say that the mainspring cannot be opened and serviced? Not very.

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36 minutes ago, steve1811uk said:

Not very helpful, even the professionals were amateurs when they started.

The point I was trying to make is not being diminutive to amateurs, into which  category I have included myself. It is that that  an expensive, specialized lubricant is not needed or adequate for a Seiko of this class, or in the hands of an amateur repairer. Which of course is my opinion only and anyone is welcome to differ with.

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I am using logic and my ears to come to the conclusion that the watch is rebanking due to poor mainspring lubrication.

I used my experience to tell even if it it is momentarily rebanking,that it is normal after being shaken, and that mainspring lubrication has nothing to do with your perceived problem. If I am wrong, that has happened to me before, and I will have no problem with that happening again. 

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Also how logical is it for Seiko to say that the mainspring cannot be opened and serviced? Not very.

Being a leading watch manufacturer surely doesn't grant that Seiko is always right, however in the famous "sealed" barrel case I believe they are, for reasons discussed into so many other similar discussions here, here's one before the others, discourage damage by hand manipulation and improvised lubrication by the inexperienced, and just to be clear that does not suggest or infer that you have done one or the other.

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Steve, if the mainspring slippage has a particular feel or sound when it happens then you can count the number of turns before slippage to give a rough indicator of how well that action is performing. 
 

I’m not that familiar with Seikos as I tend to avoid them, but I’d expect around 7-8 full turns from unwound before it starts to slip. That may sound a bit vague, but it may help as it’s a quick test to make. 
 

320 degrees sounds surprisingly strong for a Seiko. I’d maybe try giving it a few winds while it is on the timegrapher and see how it responds. 

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9 minutes ago, rodabod said:

Steve, if the mainspring slippage has a particular feel or sound when it happens then you can count the number of turns before slippage to give a rough indicator of how well that action is performing. 
 

I’m not that familiar with Seikos as I tend to avoid them, but I’d expect around 7-8 full turns from unwound before it starts to slip. That may sound a bit vague, but it may help as it’s a quick test to make. 
 

320 degrees sounds surprisingly strong for a Seiko. I’d maybe try giving it a few winds while it is on the timegrapher and see how it responds. 

Thank you for your input. I hope to be able to have a look at this again at weekend and will report back as soon as I have an update. It should be easy to see what's happening if I wind the mainspring with a screwdriver while watching the timegrapher. I do strongy expect that there is not enough slippage due to lack of the correct grease or a rough barrel wall.

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38 minutes ago, rodabod said:

I’m not that familiar with Seikos as I tend to avoid them

Be reassured, they don't bite.

38 minutes ago, rodabod said:

320 degrees sounds surprisingly strong for a Seiko. 

Not really, check below

However, 320 deg. on an old movement.t is impossible for any sustained time. What can happen when swinging 160 deg sometime the Chinese machine can't read that properly, and doubles it up.

22 minutes ago, steve1811uk said:

I do strongy expect that there is not enough slippage due to lack of the correct grease or a rough barrel wall.

It it was so easy to get maximum winding from an automatic barrel, no braking greases would be needed or sold.

Anyway, and I am repeating this here for other readers, the design of any automatic watch, Seiko or other brand, is so that no rebanking will happen, even if the mainspring is wound up to maximumum theoretically possible for its geometry.

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Anyway, and I am repeating this here for other readers, the design of any automatic watch, Seiko or other brand, is so that no rebanking will happen, even if the mainspring is wound up to maximumum theoretically possible for its geometry.


But if the spring isn't slipping properly you get the effect of holding the crown at full wind + which will make a watch which would normally have healthy but safe amplitude rebank.

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Yes, the torque shoots through the roof when you hit the very last turn of the mainspring and this can certainly happen, including on an automatic. 

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16 hours ago, rodabod said:

Yes, the torque shoots through the roof when you hit the very last turn of the mainspring and this can certainly happen, including on an automatic. 

That is the condition under which the picture in my my topic above was taken. On a Seiko that last maybe 15 seconds and then amplitude stabilizes. Watch is not actually rebanking, rate does not change much and timekeeping is not affected. The normal practice is to check amplitude 30 mins after full wind, and the 24 hrs later. Finally, worth to remind here that to get more than 280 deg on a Seiko one needs a pristinely serviced movement, with a 100% perfect hairspring, balance and escapement, plus a near new mainspring - that is a barrel complete that has never been taken apart.

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If the barrel wall is lubed with a non-breaking grease, wouldn't it slip more than it should? 

If now you are planning to use a braking grease, and in a greater quantity, it will slip less, don't you think?

I don't know if rebanking speeds a watch up, does it?

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1 minute ago, aac58 said:

If a mainspring is lubed with a non-breaking grease, wouldn't it slip more than it should? 

If now you are planning to use a braking grease, and in a greatee quantity, it will slip less, don't you think?

I don't know if rebanking speeds a watch up, does it?

I think not, if the grease is too thin or not enough then it will not provide any braking or slip. The spring will just displace the grease and brake hard against the barrel wall. That's how I see it anyway. I'm not an expert but that's what my engineering mind is telling me would happen. Rebanking definitely speeds up the rate. I'm hoping to find some time at weekend to post a short video showing the issue.

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It easy to tell, on a Seiko and I believe on most other automatic, how much braking the mainspring has. Wind it at the barrel, keeping the driver with two fingertips. After about 8 turns (I can be more exact if wanted), you may feel a very faint click, as the mainspring begins to slip, but no perceivable change in the force is eeded to continue turning. Sometime there is no tactile feedback at all, and the transition is totally smooth.

Of the many hundreds that I have handled, none has ever failed to slip the mainspring as designed, or rebank.

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Well I did a test today, dial down on the Timegrapher, fully wound then I clicked the barrel tooth by tooth. The amplitude built up and then the rate shot through the roof. I think this is rebanking and why my watch gained so much time on my brisk walk. I will open the barrel and clean and lube the mainspring again, this time with the proper stuff (8217).

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Yes, certainly looks like what you describe. I’d be interested to hear how you get on with it. It may be worth inspecting the condition of the barrel wall too.  

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20 hours ago, rodabod said:

Yes, certainly looks like what you describe. I’d be interested to hear how you get on with it. It may be worth inspecting the condition of the barrel wall too.  

Barrel wall was not worn. Cleaned, lubricated and reassembled by hand, 'tut tut'. After putting it back together I was still able to induce the rebanking with the screwdriver on the barrel. The only odd thing I did notice was that the outer turn did not follow the circular shape of the barrel wall perfectly. That came away from the wall a bit over about 120 degrees. It looked to be caused by the shape of the bridal that I don't think was curved enough to follow the barrel wall, too straight. That might be causing the spring to dig in a bit and not slip, that's all I can think of. I will see how the watch runs in use.

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That is a strange one. Do you get the same results with just a few winds. I have experienced over banking before which was because the mainspring was far too strong.

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5 minutes ago, clockboy said:

That is a strange one. Do you get the same results with just a few winds. I have experienced over banking before which was because the mainspring was far too strong.

No, it only happens when the spring is fully wound and then gets overwound either on a brisk walk or artificially from a screwdriver winding the barrel.

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