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Old Medana...eratic timekeeper!

RichParker
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RichParker Member

RichParker

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Hi, I have what looks like a really old watch with a cylinder escapement. It's not one of those silver case trench style watches that look like a miniature pocket watch with weird bent wire tabs for a strap, but it's not far off....it still has wire tabs but looks more purpose made.

It didn't run so I took it to bits, cleaned it, oiled it, put it back to bits and made the thing work which I was everso slightly amazed at because it actually runs without stopping!!... which is something I guess!....but it runs noticeably faster in certain orientations than others, so during the day while I'm wearing it, it will gain, then keep time for a period, then gain again etc. It's all over the place!

I'm guessing this is a thing, so I wondered if anyone knows why it happens. I'm a bit fed up because it's a gorgeous looking watch which I would wear all the time, but as it is.....it's basically an ornament!

Thanks

20210318_002059.jpg

KOwatch Watch Enthusiast

KOwatch

Posted
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Do you have any photos of the movement?

What positions is it running fast, and how fast?

How did you clean the hairspring?

Did you demagnetize it?

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RichParker Member

RichParker

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Thank you for replying. I cleaned everything in lighter fuel.....I read a post on cleaning and this was suggested....I very gently agitated the spring with a very soft make up brush that my daughter kindly donated to the cause! It looks in good shape, although the regulator pins are.....well the outer one is missing and the inner one is in constant contact with the spring, not displacing it to any great degree but I think there should be tiny amount of clearance when the balance is in it's middle position....say at rest?? It works in the respect that I can make the watch run generally faster and generally slower by moving it plus or minus.

 

The watch runs fast with the crown generally upward...gaining half an hour overnight, and slow with the crown generally downward....again around half an hour overnight. I guess I arrived at this by making several adjustments to the regulator over a few days of wearing, trying to make it keep at least  rough time.....like a minute or two either way.

And yes I demagnetised it straight off when I got it running, and have done a few times since just to be sure.

I'll take some photo's of the inside when I get home from work and post them.......thanks again for taking an interest.

JohnR725 Distinguished Member

JohnR725

Posted
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7 hours ago, RichParker said:

although the regulator pins are.....well the outer one is missing and the inner one is in constant contact with the spring, not displacing it to any great degree but I think there should be tiny amount of clearance when the balance is in it's middle position....say at rest?? It works in the respect that I can make the watch run generally faster and generally slower by moving it plus or minus.

I enhance the picture of your regulator pin. Are you sure it actually had two pins? In other words was there a hole for the other regulator pin? Because looking at the picture it looks like one pin only? One pin will work fine if the hairspring never leaves the pin.

Then what kind the timekeeping area expecting from this watch?

 

regulator pin interesting.JPG

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WellAdjusted Member

WellAdjusted

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Posted

A good rule of thumb is to fix the obvious faults before troubleshooting. If one of the regulator pins is missing, you have a likely answer. It would explain both the position differences and much of the overall poor rate.

The spring "breathes" against the pins. In one position, it might look like it is pressing against one, but when you rotate it 180 degrees, it might not touch anything. Likewise, and the spring runs down and the amplitude drops, the relation of the spring to the lone pin changes.

I'd start with the pins and then see what you have.

RichParker Member

RichParker

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Ok, thanks for that.

I guess I'd settle for a couple of minutes a day....either way....but as it is it kind of depends on what my activity is whilst I'm wearing it...it might keep reasonable time one day while I'm doing stuff, then gain 10 minutes the next if I'm sat down!!

So I guess fix the regulator somehow and see what that does?? I've got an idea for a bodge

Nucejoe Distinguished Member

Nucejoe

Posted
Posted

Amazing how JohnR captures this regulator pin image, WOW.

A video of the coil's top view( looking streight down) whilst running and in different positions, will be most helpful. 

 

 

 

Nucejoe Distinguished Member

Nucejoe

Posted
Posted
4 minutes ago, RichParker said:

Sorry I don't know how to use this forum properly so I can't seem to  respond to a specific answer

Click on Quote in the post you want to respond to, the entire post will be quoted in your post, you can then delete the parts you don't want.

RichParker Member

RichParker

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1 minute ago, Nucejoe said:

Click on Quote in the post you want to respond to, the entire post will be quoted in your post, you can then delete the parts you don't want.

I see!

Nucejoe Distinguished Member

Nucejoe

Posted
Posted
1 minute ago, RichParker said:

I'll look into that....thanks....although I can't guarantee it will be great quality.

You mean with the regulator in different positions right?

Right so we can observe the hairspring coil and if spring leaves the regulator slot. 

Is there an end curve to shape.

Nucejoe Distinguished Member

Nucejoe

Posted
Posted

That is too far apart,  when the oscilator comes to rest spring should be in the middle of the slot, and not leave it when running.

 

 

JohnR725 Distinguished Member

JohnR725

Posted
Posted
35 minutes ago, RichParker said:

It sort of looks like one pin that is bent underneath and back up again to act as two pins, but they are about a foot apart!

 

2 minutes ago, Nucejoe said:

That is too far apart,  when the oscilator comes to rest spring should be in the middle of the slot, and not leave it when running.

There's a limit of what I can do with photo enhancement if the detail isn't in the photo. But it does look like only one pin. I don't see any other holes for second PN

Then I could've sworn sometime in my life I've seen regulator PN that is bent in the loop and this loop is too far apart but is this the way it came from the factory? You don't want to start changing things if the factory perceived that this is what they needed.

As a reminder this is a cylinder escapement it's always in contact with the escape wheel. It even has a PN on the balance wheel to limit the motion. So if the hairspring continuously pushes against the regulator pin and never leaves even though that's not traditionally what were taught it will work fine. If it lifts off the regulator PN especially at a higher amplitude that will not be fine.

 

regulator pin not pins.JPG

RichParker Member

RichParker

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Ok, I get what you're saying.....the 'outer' pin (if that's what you can call it in this case!)...should be contacting the spring also??

So I need to narrow the gap and also move the pins inward somehow so that the spring is clear of them in the middle of its cycle??

JohnR725 Distinguished Member

JohnR725

Posted
Posted
Just now, RichParker said:

So I need to narrow the gap and also move the pins inward somehow so that the spring is clear of them in the middle of its cycle??

We need to very carefully look at the regulator and look at the peculiar pin arrangement? Does it look like it came from the factory this way even though it defies logic as we know it?

One of the things is always bad to do is changing a watch to fit within the perceptions of what we think it should look like. Even if logically and current theory it should look different.

RichParker Member

RichParker

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Ok, So my last post was incorrect.

I had best leave it then.

The wheel is a bit wonky isn't it! Maybe it's out of balance? This is all way beyond me and my capabilities tbh.

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