Positional error variations, and how would I know if I have the balance pivot endstones in the corrrect place if they are different?

[Geoffrey]

Hi all

I have been wondering what the solution is to correct or minimise the variations in rate in the different testing positions? How much is an acceptable variation between say dial down and dial up, pendant up or down etc? How does one attempt to correct such a variation and what is a great variation, or any variation, a symptom of?

Also, I rebuit an ASST 1950/1961 movement in a cheaply purchased non-runner practice movement. I have reasons to believe it had been fiddled with before I opened it. I definitely replaced the balance pivot jewel and endstone assemblies the same as I found them, but did wonder how, besides the actual physical fit of the assemblies into their receptacles, would I know if they were in the correct receptacles? What would common symptoms be? Would a significant positional error be a symtpom of that?

The movement is running tiptop now, pretty much spot on time after almost 24 hours dial up.....I am pretty stoked!

Looking forward to reading your responses. I am loving learning new things....greetings from South Africa!

[JohnR725]

I like to see a picture of what were talking about at the beginning of the discussion. Not everyone's familiar with every model watch. Would the watch found at the link below be your watch?

Then as were talking about this watch what sort of timing variations are you seeing that may be bothering you?

Also what sort a timing device are you using to measure your watch?

Then one of the unfortunate problems of a lot of the watch companies is they typically do not publish timing specifications. Some companies have but others typically do not.  the reason I bring this up because obviously the quality difference of the watch will determine how concerned we will be on timing specifications. if this was a Rolex we would be probably extremely concerned with a watch like this not as concerned.

Then I'm attaching the parts list for your watch providing it is your watch. You'll notice that the upper and lower balance jewel assemblies are physically a different size. Usually the side you can see on the balance bridge will be bigger. Even though no one will ever see this movement they usually make the side you can see look nicer. So the jewel may be bigger and physical size like parts list for this watch. Other times because of the regulator and the thickness found here the entire jewel assembly will be thicker. Sometimes the settings will be identical size but the end stone will be thicker on the side you can see. So yes you cannot make the assumption that there are identical in size. This is where having a parts list helps or depending upon whose jewel assembly it is you might have a website for the company that makes the assembly and ill give you specifications.

Then for specifications typically are not found in the spec sheets. Some companies will have separate documentation with timing specifications. Others seemingly have nothing at all. ETA unfortunately not for every watch has manufacturing information sheets. I'm attaching a couple of pages out of one of those. It's a watch kind of may be perhaps similar to yours. In any case we can use it for ideas to see what the watch company was thinking.

So in the second PDF will notice that there are four different grades of watches. Then they specify what all the differences are but we only want to look at the timing. So typically on the lowest grade watches there only time in two positions. The better the quality the more positions they verify that the watch is indeed keeping time in those positions. Doesn't mean you can't regulate you're watching get at the keep better time just means the factory didn't worry about it.

Then you'll notice that the timekeeping specification is for an average of the numbers positions they time the watch  in. Which is not the same as the instantaneous rate that you're seeing on the machine.

Then there is the maximum difference between the positions that it's time then. Notice that numbers bigger than the average or could be worse than the average.

Then you will notice at all the specifications above are based on the watches fully wound up and then There is specification is between one and three hours after it's fully wound up. This will vary between the various watch companies and you will note they give specifications for how to set your timing machine like the averaging time and stabilization time in other words when you switch positions in youth to stabilize and the minimum measuring time. Some of these numbers come about because if you have lots of money to him by nifty Swiss machines with automatic microphones it will rotate all by themselves in need this for programming that. But it also means when you switch positions you needed to stabilize and then look at it for the time specified at least .

Then we get isochronism that's the timing difference between the watch fully wound up and 24 hours later.

Then amplitude is always interesting for the watch companies versus this discussion group. Because typically the only thing they worry about is yes they don't want it too much but there only worried about it at 24 hours.

Then just because the factory only looks at the timing into positions doesn't mean you can't time it in more positions. Which is what I usually recommend for anyone repairing a watch anyway. The minimum of dial up or dial down and more than one a crown position would be.'s. Makes it easy to see that you're having a problem versus one position where you miss things.

Then if you look through the questions of the discussion group all of this has been discussed before which is why I'm not going to go into incredible details.

Simplistically if you want your watch to keep time it should be as close to perfect as possible. Then typically dial-up and dial down should be very close to the same. Then when you go to the crown/pendant positions you always lose amplitude because there's more friction resting on the sides of the pivots. Then you always or usually always see some timing difference here and this is where we could go into basically what's whole subject lots and lots and lots of paragraphs.

So this should get you started and I think I asked some questions above and I'm sure you probably have some. You can also go through the discussion group either do a search or just start scrolling down and looking at the questions because these questions of all come up before and are lurking in this group some way. Or ever lucky someone will come along and answer your question in more detail and you won't have to go looking through the message board but you'll miss out as it has been a lot of really interesting discussions.

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&AS_1950

AS_AS 1940,1941,1950,1951.pdf ETA-2824-2-Manufacturing-Info-Fr-Gr-En page 6 and 7.pdf

[Nucejoe]

Adolf Shields  movements powered many barands and was built in different grades.

You get different performance usually along with different positional adjustments out of different grades.

1 hour ago, JohnR725 said:

quality difference of the watch will determine how concerned we will be on timing specifications. if this was a Rolex we would be probably extremely concerned with a watch like this not as concerned.

 

So if the brand of your watch is for instance orator, you are likely to find an unadjusted AS movement under the hood, another brand may sell you a movement of the same caliber but better grade that is adjusted in 3 positions.

A picture would have provided a thousand data John needed to have, so to help or answer the question to the point.

Regs 

Joe

[Nucejoe]

2 minutes ago, Nucejoe said:

Adolf Shields  movements powered many barands and was built in different grades.

You get different performance usually along with different positional adjustments out of different grades.

So if the brand of your watch is for instance orator, you are likely to find an unadjusted AS movement under the hood, another brand may sell you a movement of the same caliber but better grade that is adjusted in 3 positions.

A picture would have provided a thousand data John needed to have, so to help or answer the question to the point.

Regs 

Joe

to the point and in one paragraph.

[canthus]

My take on positional accuracy is like the comments above re quality/brand etc and need for accuracy.  However most of the stuff I work on does not need such accuracy, or it is never going to be achieved, although I still strive for the best I can do. I always ask the owner how they wear the watch and get the best in 3 positions for that use.  Such considerations are left or right hand, desk based, etc.  For example a hair dresser will probably have the hands up a lot, so more accuracy with the pendant up (for left wrist wearer), office/desk wearer will have lower arms on desk a lot , so dial up and  12 0clock down are important. How do they store watch overnight, most people will be dial up.  It is hard to imagine how many people have it dial down for any significant time, try it, it is very uncomfortable!!

[Ronp]

Pivot endstones: thinnesst and smallest normally dial side.