Positional adjustment is a very complex issue, and one that I don't fully understand the theory behind(although I'm able to make many of the adjustments).

Essentially, for reasons which I don't totally understand, the pinning point of the hairspring has a huge influence on the rating in at least one position.

I have been told by watchmakers I trust that essentially the only way to "adjust" a watch to the 6th position is to relax the allowable variation on the other 5 positions.

With that said, there were a handful of American railroad watches which were adjusted to 6 positions. Probably the best(and most heavily advertised) were the better grade Illinois railroad watches like the Bunn Special, Sangamo, and Sangamo Special. Most other American companies went to at least marking for 6 positions in later years-the Hamilton 992B and 950B, for example, were marked adjusted to 6 positions, while their predecessors were only marked for 5 positions. Late Elgin gr. 571 watches were marked "9 adjustments", meaning 6 positions, temperature, and isochronism.

And, all marketing speak aside, my experience is that a watch adjusted to 5 positions which rates well in 5 positions(i.e. 2-3s/day variation from slowest to fastest across 5 positions) will generally not be more than 3-4s/day off even in the 6th position.

 

Thank you for such a detailed and informative response. It is interesting the theory that in order to adjust for the 6th the others must be sacrificed to some level.

In an attempt to feel out the watch's personality and find the best resting position (to maintain as close to +/- 0s/day as possible) I test out various resting positions with my watches as I get them. Both the Hamilton I owned and now the Omega have noticeably larger variations with the crown at 6 o'clock than the other positions which spawned the question.

The Omega I am working with now has gained 3 second in dial up, 1.5 seconds at crown up and 4.5 seconds at crown down (all averages with 2 days per position - still testing the other positions).

While we are (kind of) on the topic... is there any truth to the notion that a watch has a break-in period? That the oils may need some time to work around and settle in or that the spring needs to be worked before it can become reliable? I would think not as COSC testing is done right out of the gate right? My Hamilton seemed to settle into a more steady rate the more I wore it, but then again, this may just be perception and the fact that once the honeymoon phase wore off the only time I really looked at to-the-second accuracy was when I hacked it to reset during date changes.

 

The movements on my Nomos watches are adjusted in 6 positions.

From what I know, this is also the case for some of the Grand Seiko movements.

 

In terms of a watch being adjusted for position it typically includes 3 or 5 position adjustments with 3 position watch being crown at 3, 9 and 12 o'clock and 5 position watches adding dial up and dial down. The 6th position is then the crown at the 6 o'clock position.

Your ordering is not quite right.
This article has a good description of the order of positions, and the reasoning behind it: Timing Results on Five High-Grade Watches - TimeZone

 

Not sure adjusting to 6 positions is all that rare; my Eterna konTiki from 1970 was adjusted to 6 positions and temperatures.




~Sherry.

 

Apparently, there is just the belief that the sixth position is relatively insignificant because, when worn, the watch is rarely exposed to it. I believe some JLCs, all Grand Seikos and most Nomos (I think they started out with 5 position adjustment then moved to 6 later, but I might be mistaken) adjust in "all" six positions.

In addition to the sixth position, Grand Seiko adds a third temperature.

 

In addition to the sixth position, Grand Seiko adds a third temperature.

No it does not, ISO 3159, DIN 8319-1 and Grand Seiko tests at three temperatures 8, 23 and 38 degrees C.

 

When my seamaster was sent for service with my AD service centre it was adjusted for 6 positions. Keeps superbly accurate time now, much better than it ever did when I bought it new.

 

When you get right down to it, adjustment markings are basically meaningless without knowing the manufacturers allowed variations for the positions. When Hamilton went to marking their watches for 6 positions, it was done so at an increase in allowed variation across the 5 positions.

I think it's also worth noting that modern watches(most anything made in the last 50 years) aren't really adjusted to temperature in the classical sense. Rather, modern balance and hairspring materials just mostly eliminate temperature error. Even so, there is still some residual error. If a modern watch is regulated at "hot"(traditionally 100 degrees farenheit) and "cold"(35 degrees farenheit) it will normally show a middle temperature error of 2-3 seconds a day. There are ways to (mostly) eliminate this, and probably the best way is an uncut ovalizing bimetallic balance like used on the Hamilton 21 chronometers, although I've not heard of any modern mass-produced watch using temperature compensation. Thus, I would question the allowed variation on any watch claiming to be adjusted to middle temperature.

Watch adjusting is a very complex topic, and there are many seemingly insignificant factors which can dramatically affect the adjustment of a watch. For a hands-on take on adjusting, both DeCarle and Freid deal with the subject very well. I also have a few other, probably more obscure references on adjusting in my library which I will post here when I get a chance to pull them out. Daniels handles it better on a theoretical basis in Watchmaking.

 

Yes, when they say adjusted for two temperatures (or three for Seiko) they mean tested for those temperatures to still be within the specified range. As far as I understand, bi-metallic balances were obsoleted by superior materials.

 

In terms of a watch being adjusted for position it typically includes 3 or 5 position adjustments with 3 position watch being crown at 3, 9 and 12 o'clock and 5 position watches adding dial up and dial down. The 6th position is then the crown at the 6 o'clock position.

The 6th position is actually crown right, or 12H in the Swiss terminology. Crown down, or 9H is most certainly included in the 5 COSC measurements.

Cheers, Al

 

Yes, and the reason that crown right is the one specified to be excluded is apparently because a watch on your arm is hardly ever crown right, although depending on how the watch rests at night, it can get close to it (i.e, resting against the bracelet or leather strap).

Apparently, there were (are?) even makers that adjusted to half-positions.

 

At any rate, thermal adjustments must take into account more than the expansion of metals (for instance) since the air inside the case is affected by temperature, therefore there are elements of thermal adjustment that cannot be taken into account merely by using a bimetallic balance. While this seems silly at first, apparently the Patek Gyromax is specifically designed to minimize air resistance and thus minimize the effect of changes in air viscosity on the balance. While many manufacturers have shifted their adjustment screws to the inside of the balance wheel from the outside (Rolex, Omega, etc.) in order to minimize the space the balance takes in the case and therefore enable them to use a larger balance wheel, it probably has the side benefit of reducing the drag (and therefore reducing the effect of that particular variable). The Cartier ID 2 apparently approaches this problem by creating a new vacuum inside the case.

 

Actually, thermal expansion historically has been a relatively minor component of temperature error. The biggest problem always has been(and as I understand it still is at least to some extent) the elastic variability of the hairspring, with it becoming more stiff at lower temperatures and less stiff at higher temperatures. The old style split bimetallic balance(steel/brass) contract to a smaller diameter at high temperatures than they do at low temperatures to offset this-if thermal expansion were the only concern, the balance would be designed to remain the same diameter throughout the temperature range. The earliest "modern" hairspring alloy was called "Elinvar" which is short for Elastically Invariable.

Read the chapter in Watchmaking on balance design, where Daniel's addresses the subject much more thoroughly than I'm able to. Basically, at least to my understanding(and memory, as I haven't read it in a few months), temperature error is impossible to completely eliminate through the use of a monometallic balance wheel. Daniel's own design was to use a stainless steel wheel with bimetallic attachments to compensate for the residual temperature error, although he spoke highly of the Hamilton bimetallic ovalizing design as I mentioned above. I should clarify, too, that this design is "not your father's bimetallic balance." It uses Invar spokes with a stainless steel rim(or maybe the other way around-I don't recall exactly).

 

That's all true, but as far as I can tell, no one has ever suggested that it was the balance wheel, not the hairpsring, that caused the inaccuracy associated with thermal variables. The bi-metallic balance compensated for issues in the hairpsring and improvements in hairspring materials obsoleted the bi-metallic balance, at least, from what I've read on the subject.

When I said expansion, I specifically said it was one among many variables in order to illustrate that there are some variables that are apparently not reduced by modern materials.

Edit: The second sentence is confusing. I mean to say that improvements in materials aside, there are thermal variables that still must be taken into account, like the changing resistance of air in the case.

 

Wait, maybe there's some confusion. I wasn't clear on what you were disagreeing on me with. Are you disagreeing with my claim that bimetallic balances are obsoleted by new materials?

That might well be true, beats me, I'm just toting the standard dogma on the subject. Apparently all manufacturers feel that they can do a good enough job without them, but it's possible that they're all mistaken.

Minus the screws (or at least, taking that variable out for the moment) is it possible that a split balance makes the aero-variables more significant than a continuous wheel? Intuitively it seems to me that it would (insofar as greater air resistance makes the variable resistance due to changes in temperature more significant), but I'm definitely no expert on aerodynamics.

Well, at any rate, I'm sorry if I frustrated you with my misunderstanding. I think I have isolated what you disagree with me on and what I very well might be wrong on.

 

Wait, maybe there's some confusion. I wasn't clear on what you were disagreeing on me with. Are you disagreeing with my claim that bimetallic balances are obsoleted by new materials?

As I said, read Watchmaking and you'll see that I'm not the one disagreeing with your claim.

And, as I've said once or twice in this thread, the steel/brass split bimetallic balance as you've pictured is obsolete and would be counterproductive with any sort of modern hairspring. There are other designs of bimetallic balance which do more completely compensate for middle temperature errors. There's no requirement that they have screwed rims, either(which are a practical necessity with the steel/brass split balances). The Daniel's design has a smooth rim.

 

I interrupt this technical discussion to add:

The 6th position should totally be 'On my wrist.'

Thank you for reading.

Now back to the show.

 

I do not think any more adjustments, design improvements or material development will improve the accurancy much beyond the JLC 1000 hour, PP or Glashutte Observatory levels.

 

You'd be right insofar as improvements today, but improvements in the 1960s can easily outperform them. Seiko used to sell a production watch with the "VFA" designation in the 1960s:

These watches far exceed COSC and even Grand Seiko's own standard today.

Today, you can still buy Seikos that far exceed COSC, rated for +4/-2, tested over 17 days (as opposed to 15), 6 positions (instead of 5) and for 3 temperatures (as opposed to 2).

The primary limitation to mechanical watch accuracy today is consumer expectations. By the 1960s, Seiko and GP were already making production watches that were much more accurate than chronometers today, even Grand Seikos. So 40-50 years have passed since then and I imagine we can make things to much tighter tolerances and with better materials. The standard for a chonometer today ought to be so good it's expressed in months, not days.

 

You'd be right insofar as improvements today, but improvements in the 1960s can easily outperform them. Seiko used to sell a production watch with the "VFA" designation in the 1960s:

These watches far exceed COSC and even Grand Seiko's own standard today.

Today, you can still buy Seikos that far exceed COSC, rated for +4/-2, tested over 17 days (as opposed to 15), 6 positions (instead of 5) and for 3 temperatures (as opposed to 2).

The primary limitation to mechanical watch accuracy today is consumer expectations. By the 1960s, Seiko and GP were already making production watches that were much more accurate than chronometers today, even Grand Seikos. So 40-50 years have passed since then and I imagine we can make things to much tighter tolerances and with better materials. The standard for a chonometer today ought to be so good it's expressed in months, not days.

Absolutely. But frankly speaking, a second here or there a day is not so important.
I would rather they started improving the power reserve, maybe lubricant free movements, and such.
A PR of around 40 hours has been around for many decades.

My JLC with the 8 day movement is truly ideal. I wind it once a week. Wind and forget.

 

I tested my Nomos Tangente, which is adjusted in 6 positions, after buying it new as follows:- readings were taken twice per day at 9 o'clock against an atomic timed clock. Face up, face down, winder up, winder down, & when worn 24/7, all for five consecutive days.
In all positions the overnight readings were closer to atomic time than the day readings. To try and correct this the watch was half wound when each reading was taken but the overnight readings were still better, although this did improve the accuracy of the watch, e.g. fully wound 9am, worn 24/7 9am to 9pm -4s 9pm to 9am +0.4s =-3.6s/d. Half wound at every reading gave the following , 9am to 9pm -4s 9pm to 9am +1s =-3s/d. I am pleased with the results although I would prefer a watch going fast rather than slow.
Can anyone explain the reason for these results. I have removed the fully wound versus half wound variable from the readings and keeping it warm in the night made no difference. Also, how is an automatic set as precisely as a manual wind since it is my understanding that the self winding mechanism is removed when it is adjusted i.e. it is fully wound most of the time when worn but unwinding while being adjusted.Lastly it is also my understanding that German and Japanese watches are timed in their case and Swiss ones before casing does this matter?

 

That's very interesting. It is my understanding that Nomos movements are adjusted from 0 to +8, and if that's true, ever running slow would be out of warranty. Let me lay out your testing:

Fully wound day time: -4
Fully wound night time: +0.4
Half wound day time: -4
Half wound night time: +1

The most plausible explanation for night time difference to day time difference, excepting isochronism (i.e., less wound as it runs down at night as opposed to being constantly wound up in the day), which we are compensating for with your half wound experiment, is position. I know you say any position, but generally speaking in a properly running watch, dial up will run more positive, crown up will run more negative, although this will vary watch by watch. I'd run the experiments again at night, trying to find the most positive position, again, probably dial up, to compensate.

A 4 to 5 second positional deviation is certainly acceptable, however, and not a symptom of something wrong with the watch.

Well, let me ask for clarification: so you actually already tested in dial up and crown up positions and it made no difference? That would be very surprising on this watch--I would expect a visible difference in rate for that.

"Also, how is an automatic set as precisely as a manual wind since it is my understanding that the self winding mechanism is removed when it is adjusted i.e. it is fully wound most of the time when worn but unwinding while being adjusted."

Watches like this Nomos, Swiss chronometers and Grand Seikos are all tested and adjusted for isochronism (i.e., for changes in amplitude due to the non-constant supply of energy from the mainspring) whether manual or automatic. The testing itself doesn't change, at least I see now reason for it to change, although I have read that at least some manufacturers regulate their manual watches in order to compensate for the massive sine wave of power delivery that a manual watch sees every 24 hours. Your slight increase in rate as the watch unwinds is totally normal (i.e., an increase in 0.5 seconds overall). Automatic watches, while worn, will exhibit better performance than their the same watch in manual form, all things being equal, because they stay near the primary part of the powerband.

"Lastly it is also my understanding that German and Japanese watches are timed in their case and Swiss ones before casing does this matter?"

Japanese movements are tested before they are in the case, at least, Grand Seiko movements are, and since those are by far the most tightly adjusted movements in Asia, I suspect that would apply to all of them. German chronometers are tested in the case, but Nomos movements are not German chronometers, and honestly I'm not sure whether they're tested cased. The vast majority of Swiss watches are not tested cased, but I think JLC and Patek's internal testing is done cased.

Most collectors feel that testing cased movements is more demanding than the movement alone.

 

Thanks for your help and explanations.
Dial up fully wound at 9am is one of the worst positions am-pm -4s pm-am -3s =-7s/d Winder down am-pm -6s pm-am -1s =7s/d Winder up am-pm -4s pm-am -1s =-5s/d
I did not want to bore everyone with too much data but the reason that I did these was that although I have quite a lot of literature from Nomos in both German & English nowhere did I find any figures for accuracy mentioned.
Lastly, do watches need "run in"? I repeated the observations for the most accurate position (dial down) after four weeks and they had improved from -2 s/d to + 0.5 s/d ,fully wound as before.

 

I believe I read the 0-+8 seconds/day in the manual that came with the two Nomos I bought last year, but I admit, I just scoured Nomos' page and couldn't find ANY information on their adjustment. I don't have the watches anymore, so check your manual for me and see if you can find it. I did find this listing on Rakuten that suggested 0-8 seconds range, but it's so heavily in Engrish that...I'm not sure I want to rely on it:

Rakuten: Bauhaus design made in regular article NOMOS Nomo scrub ivory clockface rolling by hand Germany- Shopping Japanese products from Japan

I still have their big catalog in my second garage so if I might go out there and get it, not sure if it'd be in there or not.

When I get home tonight I'll see if I can't figure out what's going on. It's unusual for watches to speed up as they wear in.

 

I think that besides the Japanese and the American firms in the early 20th century , none else used the 6 adjustements

 

I think only Seiko of the Japanese, but I'm sure all current Nomos models are adjusted in 6 positions. I believe, but could definitely be mistaken, that their older movements were "only" adjusted to 5 positions. I believe that some JLCs are six position adjusted too.

I do remember reading that old Hamiltons were sometimes adjusted to 6 positions, but I'm not very knowledgeable about vintage watches.