# mantle clock curiosity



## unclejonboy (May 15, 2011)

I finished working on a simple French mantle clock some months ago, limited strip down , cleaning and oiling. It had been stopped for years, was gummed and dusty, and the main problem was the balance wheel spring was a tangled mess, no idea why... After sorting that, I got it working ok, but only for about eight or ten hours. I tried various regulation and fine tuning, but no luck. After just leaving it for weeks I came back for another go, and was pleased to see I got it running fine for days. More fine regulation and I was well pleased, I moved it into the living room and put it on top of the piano. It started to lose about an hour a day, when I'd got it down to an accuracy of less than a couple of minutes a day....I moved it to a different place in the same room and it was fine again. Back on to the piano, and way off again....back to the other place, and fine again.

I stress, for these few days the piano wasn't played.

Could the mass of the cast iron piano frame somehow affect the movement....? Is there a magnetism issue here, perhaps?

Any ideas? regards UJB


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## vinn (Jun 14, 2015)

have you read anything on clock repair? I suggest taking is apart again and you might find something that was missed. on the other hand, I might have a resident demon ?


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## Always"watching" (Sep 21, 2013)

What a fascinating question. I do wonder if the act of tuning a piano, or the hammers constantly hitting the strings, imparts a degree of magnetism to the steel of the strings. I would have thought that in general, the manufacturing technique of casting a piano frame from molten iron would have produced no magnetic field to the resultant random orientation of the iron molecules. If the changes in your clock's timekeeping are not due to magnetic field interference or something that may still need attention in the clock, what about other environmental factors such as temperature variation?

In my experience of vintage mechanical mantel clocks, regulation can sometimes be a nightmare. The worst offenders are clocks of the pendulum variety, where the clock has to be maintained in a perfectly level state. Indeed, are you sure that the surface of the piano is in the same level degree as the surface you have the clock on when it is running more or less accurately?

Whatever the case, I wish you luck with this one.


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## unclejonboy (May 15, 2011)

Thanks AW,

I agree with the issue of problematic regulation, ....environmental factors are a possibility, the workshop where I did the first servicing was where I couldn't get it to run more than a few hours.. I moved into another building to work on it second time around, and there it is quite possible there was an environmental factor at play. We have wild fluctuations in temperature and humidity here in central Portugal, day to night, week to week, season to season.

I also think that leaving it for a couple of months let the lubrication settle and penetrate, which helped the change from erratic running to an acceptable accuracy, and running for days.

As to the piano or sideboard position,, only a couple of metres apart, so unlikely temperature etc. as an issue. On the piano it is on a thick cloth, on the sideboard just plain wood...

The level could be factor. I have a pendulum mantle clock that won't run at all without the right thickness of one sheet of paper under one particular foot, that has defied the skills of all (well,three..) professional repairers/smiths it's been to.

But this is a balance wheel system which oughtn't to be that sensitive.....though I have an old Oyster that gains or loses about twenty seconds a day depending on the position I leave it on at night...,face up or down for example. If I never take it off it's accurate to a few seconds a week.

I'll check the level, and also try it on the piano without cloth underneath I'll keep you all informed. UJB


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## vinn (Jun 14, 2015)

yes, level fore and aft. pendulum clocks are tricky. I got one the other day that had been all re-bushed. does the same odd thing. ill be taking it all apart, just in case the bushings are out of line.


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## Robden (Apr 2, 2016)

Sounds like it's just out of beat.

Pendulum clock easy fix.

Balance wheel a bit trickier. The hair spring may need a slight relocation.

Rob....


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## unclejonboy (May 15, 2011)

robden said:


> Sounds like it's just out of beat......


 I did think this might be the issue as it was trial and error to get the terminal of the hairspring in the right place ....and I still don't know if it is in fact in the optimum place.

Without the test kit, how can I verify the position ?...I have this same problem with a couple of wrist watches too.....


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## Robden (Apr 2, 2016)

unclejonboy said:


> I did think this might be the issue as it was trial and error to get the terminal of the hairspring in the right place ....and I still don't know if it is in fact in the optimum place.
> 
> Without the test kit, how can I verify the position ?...I have this same problem with a couple of wrist watches too.....


 Unless you have a very good ear for such things, you will need a timing equipment.

Rob....


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