Positions affecting readings

[SiZi]

This is one of two vintage watches I am restoring. This one is a cal 620 Omega.  I just got a weishi 1000 and I’m getting very different readings from different positions. You can see this in the pics below - dial up, crown facing floor, and crown to side. My questions are:

1. what is an acceptable variance between positions? 

2. what is an acceptable amplitude for watches from the 60s and 70s, brands like Omega? 
 

thanks!

[AndyGSi]

Part of the problem could be incorrect positioning in the holder along with the
fact it looks like you're changing it's position between the different orientations.

Crown should be located in the black clip for all orientations.

[caseback]

Judging from the amplitude alone: you have not worked on/restored the movement yet?

I cannot tell you what the general consensus on "acceptable" is, but my gut feeling is that these readings won't be. 

Depending on the movement, I try to get the amplitude at least high in the 200's and get the positional errors below 10s if I can. But I'm sure there are a lot of other opinions here.. 

Edited November 15, 2024 by caseback

[SiZi]

13 hours ago, caseback said:

Judging from the amplitude alone: you have not worked on/restored the movement yet?

I cannot tell you what the general consensus on "acceptable" is, but my gut feeling is that these readings won't be. 

Depending on the movement, I try to get the amplitude at least high in the 200's and get the positional errors below 10s if I can. But I'm sure there are a lot of other opinions here.. 

that sounds reasonable. I’ll need to reclean more meticulously and test and relubricate more precisely. I’ll report back soon. 

14 hours ago, AndyGSi said:

Part of the problem could be incorrect positioning in the holder along with the
fact it looks like you're changing it's position between the different orientations.

Crown should be located in the black clip for all orientations.

Got it. I’ll keep that in mind. Also I’m thinking three positions to check are enough - dial up, crown down and crown side. Does that sound like a reasonable standard or is it too low? 

[mikepilk]

On a 'quality' watch like Omega, most would aim for 270° amplitude or more (the last 620 I serviced I got 295°). For a beginner, I would say aim for 240°+. It's not so easy on small ladies watches like this, as the small size means that any imperfections have a bigger effect. Also watches with smaller balances are generally less accurate. 

A drop in amplitude from horizontal to vertical position of about 40° is expected.

DU and CD positions look great, but the -32s/day looks to be Crown Right : which is not a position the watch is usually in. What does it look like Crown Left (one of the test positions)?

For the 620, Omega don't show an initial amplitude when wound, but list a required amplitude after 24h as  160°  (which is enough to send many who post here in to shock).

It also shows the Delta 0h as 40s. This is the difference between the lowest and highest values in the positions tested, which are 3 for your watch : DU, DD, Crown Left.

 

[Neverenoughwatches]

17 hours ago, SiZi said:

This is one of two vintage watches I am restoring. This one is a cal 620 Omega.  I just got a weishi 1000 and I’m getting very different readings from different positions. You can see this in the pics below - dial up, crown facing floor, and crown to side. My questions are:

1. what is an acceptable variance between positions? 

2. what is an acceptable amplitude for watches from the 60s and 70s, brands like Omega? 
 

thanks!

I understand you not wanting to scratch the side of the case but the piece of cloth you have wedged in might be interfering with resonance that the tg could be relying on.  Not echo....just maybe dampening the sounds that the tg needs to pick up from the escapement  to give an accurate reading. The mic should to be close to the escapement or an item that tranfers the noise produced....such as the crown. Take out the cloth and add some sellotape to the metal clamp.

[SiZi]

1 hour ago, Neverenoughwatches said:

I understand you not wanting to scratch the side of the case but the piece of cloth you have wedged in might be interfering with resonance that the tg could be relying on.  Not echo....just maybe dampening the sounds that the tg needs to pick up from the escapement  to give an accurate reading. The mic should to be close to the escapement or an item that tranfers the noise produced....such as the crown. Take out the cloth and add some sellotape to the metal clamp.

Yes I started to suspect this and so I’ve removed it. Will do the new tests without any tape there

1 hour ago, mikepilk said:

On a 'quality' watch like Omega, most would aim for 270° amplitude or more (the last 620 I serviced I got 295°). For a beginner, I would say aim for 240°+. It's not so easy on small ladies watches like this, as the small size means that any imperfections have a bigger effect. Also watches with smaller balances are generally less accurate. 

A drop in amplitude from horizontal to vertical position of about 40° is expected.

DU and CD positions look great, but the -32s/day looks to be Crown Right : which is not a position the watch is usually in. What does it look like Crown Left (one of the test positions)?

For the 620, Omega don't show an initial amplitude when wound, but list a required amplitude after 24h as  160°  (which is enough to send many who post here in to shock).

It also shows the Delta 0h as 40s. This is the difference between the lowest and highest values in the positions tested, which are 3 for your watch : DU, DD, Crown Left.

 

This is super helpful! Thanks so much for sharing ! 

[AndyGSi]

1 hour ago, SiZi said:

Yes I started to suspect this and so I’ve removed it. Will do the new tests without any tape there

This is super helpful! Thanks so much for sharing ! 

Why can't you just put the movement the correct way with the crown in the black plastic holder?

Edit

Apologies but on seeing this video it would appear I've been using it wrong all along.

 

Edited November 16, 2024 by AndyGSi

[SiZi]

2 hours ago, AndyGSi said:

Why can't you just put the movement the correct way with the crown in the black plastic holder?

Edit

Apologies but on seeing this video it would appear I've been using it wrong all along.

 

Ooh, I had this video queued for tonight  Thanks for sharing! I was wondering why one end was metal and suspected it might be functional. Glad I know for sure now. Will be mindful about this.

[AndyGSi]

11 minutes ago, SiZi said:

Ooh, I had this video queued for tonight  Thanks for sharing! I was wondering why one end was metal and suspected it might be functional. Glad I know for sure now. Will be mindful about this.

Yes I was told that the slot in the black plastic clip was a space for the crown and if you look at nearly all other YouTube videos that
appears to be the case but I trust what Chronoglide Watchmakers shows although I'd be interested in what other forum members do?

[Neverenoughwatches]

2 minutes ago, AndyGSi said:

Yes I was told that the slot in the black plastic clip was a space for the crown and if you look at nearly all other YouTube videos that
appears to be the case but I trust what Chronoglide Watchmakers shows although I'd be interested in what other forum members do?

As Kalle says Andy....the metal clip is the extension of the mic. I often do put the crown into the recess of the plastic clamp which then places the mic at the escapement end of the movement. Tbh i dont think the difference is that great, though i have had watches that have given various readings when positioned differently in the clamp.

[SiZi]

On 11/16/2024 at 3:23 PM, mikepilk said:

On a 'quality' watch like Omega, most would aim for 270° amplitude or more (the last 620 I serviced I got 295°). For a beginner, I would say aim for 240°+. It's not so easy on small ladies watches like this, as the small size means that any imperfections have a bigger effect. Also watches with smaller balances are generally less accurate. 

A drop in amplitude from horizontal to vertical position of about 40° is expected.

DU and CD positions look great, but the -32s/day looks to be Crown Right : which is not a position the watch is usually in. What does it look like Crown Left (one of the test positions)?

For the 620, Omega don't show an initial amplitude when wound, but list a required amplitude after 24h as  160°  (which is enough to send many who post here in to shock).

It also shows the Delta 0h as 40s. This is the difference between the lowest and highest values in the positions tested, which are 3 for your watch : DU, DD, Crown Left.

 

I have now re-cleaned and re-lubricated. I even tried ideas like cleaning the pinions of the balance and wheels on a fine abrasive eraser. Lubrication was way more precise this time around, as expected due to increasing experience. So I’m glad I did this, however, it hasn’t changed the amplitude. My readings are attached below. If I use Mike’s resource of factory prescriptions as a reference for performance to expect from my cal. 620 then I’m doing pretty good. My readings are taken 15 hours post reassembly running. I am below the delta rate (22 sec vs 40 sec) higher than the expected amplitude in all positions (180-228 vs 160), and below beat beat error of 1. From the factory prescription, it doesn’t seem like this was built to be a high precision caliber. I think this is the best I can expect this 60 year old watch to do. But I’m a beginner, so please let me know if you have a difference in opinion. Thanks as always!

 

[AndyGSi]

Is this still the old mainspring?

[JohnR725]

On 11/15/2024 at 8:52 AM, AndyGSi said:

Crown should be located in the black clip for all orientations.

I'm attaching a PDF that you might find interesting and it also shows how a case up watch is to be held in the  machine microphone. Although the word microphone isn't technically correct as the microphone is picking up of vibration preferably not audio from the air. So cased up watches are sometimes hard to pick up because the case absorbs things or you have plastic movement rings or heavy cases or variety of issues so you get the best signal out of the watch the crown goes out. In other words it goes against the metal contact as the sensor is found down below.

 then if you're holding the movement you're supposed to hold it like the image below. Doesn't really matter which way the crown stem goes as you're picking up the vibration from the entire movement. Which is why it's very important that the metal not have tape or other stuff on it. Then it is nice if the stem would go out as it does make a nice reference to keep track of what you're doing. In the case of the watch below there is no stem as this is a key wind setting watch.

 

On 11/15/2024 at 11:22 PM, SiZi said:

Got it. I’ll keep that in mind. Also I’m thinking three positions to check are enough - dial up, crown down and crown side. Does that sound like a reasonable standard or is it too low?

for diagnostic purposes you should look at the watch in six positions. But if you look at the technical specifications of the various watch companies they will specify the actual positions such as this watch is a standard three position Omega watch and the three positions are found in the image below

then in addition to the various positions there are procedural things that you should follow which are mentioned way up above on the specifications although Omega does have some minor variations. To understand procedures I'm attaching an image. 

On 11/16/2024 at 1:53 AM, mikepilk said:

For the 620, Omega don't show an initial amplitude when wound, but list a required amplitude after 24h as  160°  (which is enough to send many who post here in to shock).

yes those crazy people at Omega knowing that the people in this discussion group will probably have a heart attack and die when they see that number. Although it's not just Omega I've seen some of the others Swiss companies will specify bizarrely low amplitudes it 24 hours. Of course the watch still has to keep time

 

 

8643_WI_81 BASIC CHECKS AND SETTINGS OF A MECHANICAL WATCH_EN cousins.pdf

[SiZi]

2 hours ago, AndyGSi said:

Is this still the old mainspring?

No, it’s a new mainspring

17 minutes ago, JohnR725 said:

I'm attaching a PDF that you might find interesting and it also shows how a case up watch is to be held in the  machine microphone. Although the word microphone isn't technically correct as the microphone is picking up of vibration preferably not audio from the air. So cased up watches are sometimes hard to pick up because the case absorbs things or you have plastic movement rings or heavy cases or variety of issues so you get the best signal out of the watch the crown goes out. In other words it goes against the metal contact as the sensor is found down below.

 then if you're holding the movement you're supposed to hold it like the image below. Doesn't really matter which way the crown stem goes as you're picking up the vibration from the entire movement. Which is why it's very important that the metal not have tape or other stuff on it. Then it is nice if the stem would go out as it does make a nice reference to keep track of what you're doing. In the case of the watch below there is no stem as this is a key wind setting watch.

 

for diagnostic purposes you should look at the watch in six positions. But if you look at the technical specifications of the various watch companies they will specify the actual positions such as this watch is a standard three position Omega watch and the three positions are found in the image below

then in addition to the various positions there are procedural things that you should follow which are mentioned way up above on the specifications although Omega does have some minor variations. To understand procedures I'm attaching an image. 

yes those crazy people at Omega knowing that the people in this discussion group will probably have a heart attack and die when they see that number. Although it's not just Omega I've seen some of the others Swiss companies will specify bizarrely low amplitudes it 24 hours. Of course the watch still has to keep time

 

 

8643_WI_81 BASIC CHECKS AND SETTINGS OF A MECHANICAL WATCH_EN cousins.pdf 1.25 MB · 0 downloads

John this is a super useful resource and I appreciate your explanations too. Thank you so much for sharing this! 

[AndyGSi]

16 minutes ago, SiZi said:

No, it’s a new mainspring

So the next question is it the correct mainspring?

[SiZi]

3 hours ago, AndyGSi said:

So the next question is it the correct mainspring?

I found the parts list number (1208) from a parts catalogue online and then searched on Cousins. See the circled one, that’s what I bought. It was my first purchase/restoration - in hindsight I would have bought the much cheaper GR one instead. But, the one I bought should be the right size/measures, no? 

Also I wound the watch up fully to measure its vitals at 0 hr, and below are the readings… I gave it a minute to stabilze before taking the readings. I’ll take another set of readings at 12 hr. Also, I placed the crown against the steel part of the timegrapher, as pictured.

Edited November 18, 2024 by SiZi

[mikepilk]

Wow, that's a lot for a mainspring. I use the GR ones.

Those plots look good, it should keep good time.  The amplitude may improve after a day or so.

If you want an accurate watch, the timegrapher is just the starting point, the true test is to wear the watch for a week, and see how it performs. 

[JohnR725]

8 hours ago, SiZi said:

John this is a super useful resource and I appreciate your explanations too. Thank you so much for sharing this! 

cousins is an interesting site for technical documentation. so for instance newer Omega parts list available on the website for download I'm just attaching the PDF speedup things. usually for anything technical especially vintage is usually  black and white and not always the best resolution depending upon when it was scanned. this one because it's in color and the watermarks was downloaded direct from Swatch group. It really is a shame that Swatch group is so secretive with the documentation

then the link below you can see the rest of the working instructions they does have a tiny sampling of what Swatch group has but they do have some interesting things like the lubrication and the one that I already gave you.

https://www.cousinsuk.com/document/search?SearchString=working

 

 

 

378_Omega 620 New cousins.pdf

[SiZi]

5 hours ago, JohnR725 said:

cousins is an interesting site for technical documentation. so for instance newer Omega parts list available on the website for download I'm just attaching the PDF speedup things. usually for anything technical especially vintage is usually  black and white and not always the best resolution depending upon when it was scanned. this one because it's in color and the watermarks was downloaded direct from Swatch group. It really is a shame that Swatch group is so secretive with the documentation

then the link below you can see the rest of the working instructions they does have a tiny sampling of what Swatch group has but they do have some interesting things like the lubrication and the one that I already gave you.

https://www.cousinsuk.com/document/search?SearchString=working

 

 

 

378_Omega 620 New cousins.pdf 3.4 MB · 3 downloads

Thank you for bringing this to my notice - the lubrication PDF was very insightful! 

[SiZi]

9 hours ago, JohnR725 said:

cousins is an interesting site for technical documentation. so for instance newer Omega parts list available on the website for download I'm just attaching the PDF speedup things. usually for anything technical especially vintage is usually  black and white and not always the best resolution depending upon when it was scanned. this one because it's in color and the watermarks was downloaded direct from Swatch group. It really is a shame that Swatch group is so secretive with the documentation

then the link below you can see the rest of the working instructions they does have a tiny sampling of what Swatch group has but they do have some interesting things like the lubrication and the one that I already gave you.

https://www.cousinsuk.com/document/search?SearchString=working

 

 

 

378_Omega 620 New cousins.pdf 3.4 MB · 3 downloads

Thank you for bringing this to my notice - the lubrication PDF was very insightful! 
 

12 hours later, the readings are as follows… I’ll take another set of readings at 24 hours (and having my wife wear it for 8 hours).

Edited November 19, 2024 by SiZi

[JohnR725]

47 minutes ago, SiZi said:

12 hours later, the readings are as follows… I’ll take another set of readings at 24 hours (and having my wife wear it for 8 hours).

I know I shouldn't say this they will get their Tar and feathers and burn me at the stake. On this group there is a magical amplitude that you must hit or your life will be terminated in a slow painful fashion. But if you look at the Omega specifications for your watch all they care about well really all they care about is timekeeping. Then for a lot of vintage watches the minimum amplitudes are actually very low at 24 hours with the specifications still being timekeeping within specifications.

Then the reality is the most important of all is what does the watch do when somebody is wearing the watch. I remember a while back where somebody had a lady's new old stock watch that he wanted to give to his aunt. There was a several page discussion of its problems and the problems He had with timing it. All of which I'm going to skip over because in the end he gave the watch to his aunt and she was happy as can be. So that really is the most important thing that the owner is happy with the timekeeping.

[SiZi]

1 hour ago, JohnR725 said:

I know I shouldn't say this they will get their Tar and feathers and burn me at the stake. On this group there is a magical amplitude that you must hit or your life will be terminated in a slow painful fashion. But if you look at the Omega specifications for your watch all they care about well really all they care about is timekeeping. Then for a lot of vintage watches the minimum amplitudes are actually very low at 24 hours with the specifications still being timekeeping within specifications.

Then the reality is the most important of all is what does the watch do when somebody is wearing the watch. I remember a while back where somebody had a lady's new old stock watch that he wanted to give to his aunt. There was a several page discussion of its problems and the problems He had with timing it. All of which I'm going to skip over because in the end he gave the watch to his aunt and she was happy as can be. So that really is the most important thing that the owner is happy with the timekeeping.

Hi John, I appreciate your perspective and I can understand that sometimes there is a tendency to get a bit too technical / clinical about things, in any hobby. I’ve experienced this with vintage guitar and vintage pen restoration, which I have more experience with. I’m new to watch restoration so I’m building my own ideas slowly. But, what you shared resonates with me. For example, this watch was a gift to my wife who will wear it for a few hours a few days a month. The readings I have thus far are well adequate for such functionality. My expectations might be different if I were restoring a workhorse timepiece or even a high precision Rolex etc. Also, I feel like factory specs / prescriptions like what you shared for the 620 might at the very least be suitable as a floor measure and anything above that might be considered better than expected? After all, every movement has limitations - they weren’t all made equal, and so this should be taken into consideration. But I am still a novice so I am sure that slowly with time I will build a more nuanced point of view with experience. I do appreciate all the perspectives and insights being shared by more experienced members on this forum, like yourself. You are an active and very generous group of members! I am glad I found this place

[JohnR725]

17 minutes ago, SiZi said:

My expectations might be different if I were restoring a workhorse timepiece or even a high precision Rolex etc. Also, I feel like factory specs / prescriptions like what you shared for the 620 might at the very least be suitable as a floor measure and anything above that might be considered better than expected?

Timekeeping specifications are always interesting and now that people have nifty timing machines that are affordable amplitude is now number one at least on the discussion groups.

Then timing things PDF is attached with how to do all the nifty calculations if you really want to get obsessed with nifty calculations. It's so much nicer feel the timing machine that does this for you but typically there very expensive especially if the microphone rotates around to all the various positions.

Here is an image out of a vintage timing machine manual for timing specifications. Notice no amplitude as cheap timing machines that measured amplitude did not exist. That's also why you cannot find listings of lift angles for vintage watches unless somebody today measured that which is easy to do because they didn't have a nifty timing machine that could do amplitude

Then while some of the Swiss companies do have timing specifications for their watch most of them are Swatch group which means you'd not going to see the entire sheet at the best you might see a snippet. In the case of Omega I think almost all the watches have been time except they do have a generic category. So this would basically be timing for a nice all of the watchThen of minor amusement depending upon which version  in other words they kept updating this the Stabilization and measurement time seems to very. With no problem with their longer if you go too short on these you can end up with timing issues. Like moving the microphone really fast and not allowing it time to stabilize that will be an issue and usually if you run the timing in a position longer things will stabilize and be better plus of course you can change the averaging time in the machine to longer time interval to smooth things out.

 

 

 

X-D-DVH-Di-Im-N_EN witchy calculation of numbers timing.pdf

[Klassiker]

4 hours ago, JohnR725 said:

they will get their Tar and feathers and burn me at the stake.

If I could find the Bergeon part numbers I'd be on my way over there now!