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Meantime Screws


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I am working on a beautiful 21 Jewel Gold Splashed Elgin movement and it is running way to fast, past the adjustment leaver. So the question is, do I just unscrew the meantime screws on the balance (2 Screws, equal turns) or do I also do the Quarter Screws?e740261656b2b99a1d9fc7536157f6bf.plist9329a5300ea0e53bf5b7634d519f5f37.jpg048bbf91cb7fe87e120e0ac4f3d6d373.jpg

The balance is in beat after I adjusted the collet (approx .5 ms).

 

 

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The ones on the arms are know as 'Mean Time Arm screws' and the ones in the middle are 'Meantime Rim Screws'.

I've never had to do this but when you think about it you must adjust all 4 equally or the balance will go out of poise.

Henry Fried's book says half a turn can give or take out to a minute a day.

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I've just noticed in the photos it looks like the mean time screws are all screwed in flush with the rim of the balance, usually they are unscrewed slightly from factory to regulate the watch, the fact they are all screwed in makes me think someone has fiddled with it.

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I only see 2 meantime screws at the arms, no other "adjustable" screws. If you have 4 you very much can move them in pairs, no need to touch all 4. Start with quarter turns, and see what the result is. If you get more than maybe 3 turns out from the rim you should try adding timing washers (in pairs, opposing screws of course).

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I've just noticed in the photos it looks like the mean time screws are all screwed in flush with the rim of the balance, usually they are unscrewed slightly from factory to regulate the watch, the fact they are all screwed in makes me think someone has fiddled with it.

I agree. The watch was running way too fast. I have turned all 4 screws and perhaps only needed to turn the Meantime Screws. I have around 2 turns on the meantime and 1 turn on the rim screws. The rim screws feel a bit loose and I may screw them back in and just work with the Meantime screws.


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I only see 2 meantime screws at the arms, no other "adjustable" screws. If you have 4 you very much can move them in pairs, no need to touch all 4. Start with quarter turns, and see what the result is. If you get more than maybe 3 turns out from the rim you should try adding timing washers (in pairs, opposing screws of course).

Very good advice. I do have timing washers and may add a set to the meantime screws to set the regulator arm in the middle.


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Just now, jdrichard said:


I agree. The watch was running way too fast. I have turned all 4 screws and perhaps only needed to turn the Meantime Screws. I have around 2 turns on the meantime and 1 turn on the rim screws. The rim screws feel a bit loose and I may screw them back in and just work with the Meantime screws.


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I don't see any adjustable screws apart from the 2 at the arms, so it's normal they'd feel loose if you did others. Meantime screws will always have longer threads than the rest.

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I don't see any adjustable screws apart from the 2 at the arms, so it's normal they'd feel loose if you did others. Meantime screws will always have longer threads than the rest.

I think i "screwed" up. I screwed back the quarter screws as well and I don't think they are quarter screws. Plan B is to screw them back in and turn out the meantime screws one or two more turns...add washers if I have more than 3 turns as recommended and see where I get. BTW, I'm doing this with the balance in place but hold it carefully with tweezers. Any issue there?

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BTW, I'm doing this with the balance in place but hold it carefully with tweezers. Any issue there?

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Well you're risking the pivots if you end up putting too much pressure, but it is done that way by many.

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Well you're risking the pivots if you end up putting too much pressure, but it is done that way by many.


I am being very careful. The watch has a 550 deg swing, amazing amplitude (270). So after 2 days the watch stopped. The non-quarter screw that I accidentally turned, thinking it was a timing screw as well, turned out on it’s own and ended up touching the balance cock. So I tightened the screw and it’s brother and turned the Meantime Screws another 2 turns. Watch is still at +60 seconds a day. When I get home I will add timing washers to the meantime screws at the arms of the balance and get the darn thing timed.


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I am being very careful. The watch has a 550 deg swing, amazing amplitude (270). So after 2 days the watch stopped. The non-quarter screw that I accidentally turned, thinking it was a timing screw as well, turned out on it’s own and ended up touching the balance cock. So I tightened the screw and it’s brother and turned the Meantime Screws another 2 turns. Watch is still at +60 seconds a day. When I get home I will add timing washers to the meantime screws at the arms of the balance and get the darn thing timed.


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No, washers only go on the normal screws, and get tightened down.
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Quarter screw and meantime screw means the same thing, I think the Brits say "quarter" more where Yanks say meantime. Some watches have 4, at 90 degree spacing (thus "quarter screw"), some just 2. When there are just 2 they are typically at the arms like in your watch. They are just for getting the balance close to a general (mean) time, with the regulator in the middle of its course. It's very much discouraged to use them for correcting poise error, although you can if it's just a small adjustment.

 

So you have two meantime or quarter screws, the rest are just balance screws. The meantime screws will always have a longer thread, and show some resistance to turning even when not screwed down- they will in fact generally not be screwed right down to the rim. The regular balance screws will always be a free fit on the thread, and always need to be screwed down tight. Timing washers are used on these screws if needed.

 

Balance screw holders are very nice to have, really essential for small balance screws, when dealing with adding washers. They are essentially little pinvices with sized tips, Bergeon sells them.

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Quarter screw and meantime screw means the same thing, I think the Brits say "quarter" more where Yanks say meantime. Some watches have 4, at 90 degree spacing (thus "quarter screw"), some just 2. When there are just 2 they are typically at the arms like in your watch. They are just for getting the balance close to a general (mean) time, with the regulator in the middle of its course. It's very much discouraged to use them for correcting poise error, although you can if it's just a small adjustment.
 
So you have two meantime or quarter screws, the rest are just balance screws. The meantime screws will always have a longer thread, and show some resistance to turning even when not screwed down- they will in fact generally not be screwed right down to the rim. The regular balance screws will always be a free fit on the thread, and always need to be screwed down tight. Timing washers are used on these screws if needed.
 
Balance screw holders are very nice to have, really essential for small balance screws, when dealing with adding washers. They are essentially little pinvices with sized tips, Bergeon sells them.

So the timing washers would be placed on the two opposing screws that are 90 deg from the balance arms. Is this correct? By the way, thanks for the advice. And is there a book that explains the placement of timing screws . I do have the tools needed to work with the balance screws:)


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You can put the timing washers on any two opposing screws, except meantime screws. Almost any watchmaking text should cover it, I'm sure Gazeley Decarle Fried and others go into it.

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17 minutes ago, jdrichard said:


So the timing washers would be placed on the two opposing screws that are 90 deg from the balance arms. Is this correct? By the way, thanks for the advice. And is there a book that explains the placement of timing screws . I do have the tools needed to work with the balance screws:)


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      do you a screw driver that will hold that little "cheese head" screw?     vin

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      do you a screw driver that will hold that little "cheese head" screw?     vin

I have all the tools...trust me:)


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id like to know what kind of small size screw driver is available.  im shure you have more watch tools than i     vin

Perhaps. Just got this toola43f9a1b477b9c85a66104e976f053ad.jpg


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There are much more elaborate sets of timing washers, for a given size of watch there are usually 3-6 different washers possible. You can see the carton boxes are marked on the lid, the wooden Bergeon set inside, the Bergeon gives the watch size and hole size in the washer. Of course there can be balances with different inertia in a given ligne size so the "seconds per day" is an approximation.

 

I'm sure with your set you'll find some that get your watch on track.

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