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Poise issue? Seiko 7625 with Renata 1594 balance


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Really appreciate all of the detailed input. I will investigate further and see what I can find.

Some things that I can confirm though.

Hairspring is flat and not rubbing anything.

Pivot end shake, there is a small amount confirmed by up and down movement of the balance rim and also be watching the pivot through the jewel with binocular microscope.

Pivot side shake, there is nothing perceivable either visibly with the microscope or by side movement. Absolutely nothing, feels solid when balance rim is gently tapped with tweezers. Balance rim or pivot do not move sideways at all when grabbed with tweezers. I am going to install the old balance and check side shake on that as a comparison. That is currently not running true as I inadvertently twisted a balance arm, but for sideshake comparison it will be ok.

Regulator gap is small with spring centred. Different spacing has been investigated from tiny gap to wide. Even with tiny gap the vertical rates are very slow with the same low amplitude be region of -60 degrees from DU/DD amplitudes.

Incidentally, the horizontal rate is good now with the regulator in the middle of its range. Tungsten drill at 0.5 mm was a bit too big, I would recommend 0.3mm or 0.25mm for these small rims.

Thanks again

IMG_20201110_200421517.jpg

IMG_20201110_200414756.jpg

Screenshot_20201110-200647.png

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with your microscope use did you actually look at the pivots themselves? then the really hard when the sea is the hole jewel for the balance. It really nice to look at that make sure it's shiny and smooth.

10 hours ago, steve1811uk said:

Pivot side shake, there is nothing perceivable either visibly with the microscope or by side movement. Absolutely nothing, feels solid when balance rim is gently tapped with tweezers.

I would hope that I'm not reading this correctly? There always has to be a little play in that the part has to deal of rotates and if there is zero clearance then it's not going to rotate. There is always the possibility of that the replacement balance wheel pivots is slightly larger than the original pivot? Maybe for the fun of it put the old balance wheel back in and see what that's like as far as clearances go.

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11 minutes ago, JohnR725 said:

with your microscope use did you actually look at the pivots themselves? then the really hard when the sea is the hole jewel for the balance. It really nice to look at that make sure it's shiny and smooth.

I would hope that I'm not reading this correctly? There always has to be a little play in that the part has to deal of rotates and if there is zero clearance then it's not going to rotate. There is always the possibility of that the replacement balance wheel pivots is slightly larger than the original pivot? Maybe for the fun of it put the old balance wheel back in and see what that's like as far as clearances go.

There must be some clearance but it is the smallest that I have encountered, saying that I have only worked on less than ten old watches up to now. I had a thought that the old pivot would have had more clearance in the jewel due to wear. Looking at the jewels again today they are not spotlessly clean. Maybe the new oil has loosened some gunk over the past few weeks while I have been trying to complete the watch. Not enough to affect the old balance, but plenty to slow down the new one with the much smaller clearances. Anyway, jewels are back in the ultrasonic. I will hopefully fit them tomorrow and also try out the clearance of the old balance. Fingers crossed.

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On 11/9/2020 at 3:37 PM, Nucejoe said:

To check the balance wheel for poise, just put the balance and cock back on mainplate( without the fork and preferably no other parts), then in vertical position heavier side comes to rest at 6 oclock( bottom of the hour), ink- mark the spot.

 

On 11/10/2020 at 6:01 AM, Nucejoe said:

This probably has been a major cause of my failure to poise.

? I really appreciate your honesty Nuce, you're certainly one of a kind! Sorry for being OT!

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IMG_5354.JPG.f89bdfaacb012aaa259ad47d239d38db.JPG

@JohnR725 I've been reading your posts about poising in this thread with great interest. I haven't tried poising any balance as of yet but I have some Vostok wrist watch movements that would likely benefit if they were poised.

I'm not looking for perfection but for improvement and if I get you right, and if you could please confirm, I believe that what you say, in principle, is that static posing (using a poising tool) is more convenient than dynamic posing although not as precise? I guess because the hairspring is taken out of the equation during static poising?

Right now I have a Vostok cal. 2409 (seen in the picture) that is running beautifully with 310 degrees in the horizontal positions and around 285 degrees in the vertical positions. Here are the current rates for the various positions:

DU: -3
DD: -8
PU: +25
PL: +17
PD: -27
PR: -4

What kind of results do you believe static poising would do for this movement if done correctly? I'd really appreciate your input!

Edited by VWatchie
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Before someone is running into traps, please study that picture. It shows the influence of a heavy spot below at different amplitude. 
As you can see, influence is zero at about 220 degrees, and it changes from fast to slow under and over 220 deg.!

poise1.jpg.348ca066ab1c9777bbb20f6339c57e14.jpg

Quote

I just checked and that heavy spot indicated in the video is below the balance pivot when the watch is midway between PD and PL (The two positions with the equally slowest rate, -65). I think that's expected and it's starting to make sense.

Not at all ?.

Frank

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59 minutes ago, praezis said:

Before someone is running into traps, please study that picture. It shows the influence of a heavy spot below at different amplitude. 
As you can see, influence is zero at about 220 degrees, and it changes from fast to slow under and over 220 deg.!

poise1.jpg.348ca066ab1c9777bbb20f6339c57e14.jpg

Not at all ?.

Frank

Thank you, I think I have found the issue and it's nothing to do with poise.

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precision timekeeping involves more than poising. The watch has to be running correctly in the first place as poising is not going to fix problems of the watch having a problem.

statically poising is the balance wheel itself without the hairspring. It's always good to start here if you think you have a problem. then as pointed out previously you can have the balance wheel in the watch and notice positional error but they show up much better if you have an actual poising tool.

dynamic poising is not a substitution for proper static poising. I tend to think of it more for people obsessed with  precision timekeeping. Because if you statically poise even relatively close for most things it's going to be good enough. Dynamic poising takes into account the hairspring and its collet.

I'm attaching a different image showing the same thing the effect of poise with amplitude. At low amplitudes not just positional errors but everything gets magnified. so we see the effect of as amplitude increases until you get around 220° something interesting happens positional errors are canceled out. Going over 220° the effect of a positional error is considerably less. from looking at either of our charts you can see why dynamically poising should be done at a low amplitude because of make it much easier to see if you are problems. Then when they are reasonably could at high amplitudes will just totally disappear.

Then the cautionary warning for newbies. It's easy to jump on what looks like it might be your problem but it may not be there is a lot of things that can affect timekeeping. As at a lecture on precision timekeeping and towards the end he was asking questions and people are looking at the image and say well it's out of poise it's this that just a little bit and what was the solution they change the balance staff. Balance pivots have to be absolutely perfect.

Then there are the hidden things that you can't see us have the right timing machine. Like the above example the Vostok that apparently has now been decided it was not a poising issue but we still don't know what that issue is? What's interesting was some watches is if you run a timing cycle of six positions at ailing to get through you wait a little bit and run it again it's really nice if you a timing machine with automatic microphone that does this for you see if they change? The gear train is not perfect you can have power fluctuations because of gear train issues that you're probably never going to fix. This power fluctuations will show up as timekeeping issues. A lot of ways they're not a problem the watch will average out all of this but instantaneously on your timing machine you can see issues because a powertrain fluctuations. Lots of things can affect timekeeping  And running of the watch.

poise of balance wheel versus amplitude.JPG

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I did some more cleaning of the balance jewels, made sure that the hairspring was pretty much perfectly flat and centred. I then confirmed that nothing was rubbing anywhere. Guess what, no improvement. I then turned my attention to the old balance. I did a comparison of the pivot diameter on the old and new, old one measured 0.04mm, new one 0.06mm (measured with Vernier caliper). Also I measured amplitude of the new balance, initially 270 ish, then 10 minutes after full wind, DU/DD 240 degrees (adjusted to 0 SPD), vertical 190 degrees (-90 SPD). Then I continually slowly turned the mainspring while in vertical so that amplitude increased to 240 degrees, the rate however still showed around -50 SPD. I am suspecting that the pivots on the new balance are too wide, too much friction, maybe Renata got that wrong. Any thoughts on that? Photo attached showing the Pivots.

Screenshot_20201114-192036.png

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I found you a list of cross references for balance completes for your watch. Then found one on eBay.

If you had access to watchmaker's lathe you could reduce the pivots size down. A lot of times on replacement balance staffs especially after market that they were deliberately made over size. but on a balance complete seems I should have been the right size in the first place.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=T_[E_FS

https://www.ebay.com/itm/114511274297

 

 

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1 hour ago, JohnR725 said:

I found you a list of cross references for balance completes for your watch. Then found one on eBay.

If you had access to watchmaker's lathe you could reduce the pivots size down. A lot of times on replacement balance staffs especially after market that they were deliberately made over size. but on a balance complete seems I should have been the right size in the first place.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=T_[E_FS

https://www.ebay.com/itm/114511274297

 

 

Thanks John,

I have made enquiries with a local repairer for the pivot job. That might work out lower cost than £40+. In your experience would an oversized pivot cause the issues that I have been seeing? Unfortunately I don't have a lot of experience to draw upon as I've only been persuing this hobby for around 6 months. Steve.

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Good work spotting the difference in the pivot diameters. I would not have expected that. I do wonder if that would also affect the DU/DD positions though. 
 

As crude as it may sound, you could probably reduce those pivot widths slightly using a small pin vice, some hard wood and some Autosol or similar. Just as you would do to manually polish a wheel pivot by hand without using a lathe. 

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On 11/13/2020 at 2:09 PM, VWatchie said:

 

? I really appreciate your honesty Nuce, you're certainly one of a kind! Sorry for being OT!

Everybody is ignorant, only on different subjects.

                                                                                  Will Rogers.

 

You shouldn't waste your time on judging me or count my failures, ignorances and stupidities. DO something about your own.

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10 hours ago, Nucejoe said:

In vertical position, oscilator up & down  also oscilator left or right, might indicate depthing in escapement.

Or,  Have you checked side shakes in the escapement? 

Have you got the old mainspring in the barrel? 

 

Yes, didn't change the mainspring, just cleaned and lubricated. Escapement seems ok as far as sideshake and lock is concerned.

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13 hours ago, rodabod said:

Good work spotting the difference in the pivot diameters. I would not have expected that. I do wonder if that would also affect the DU/DD positions though. 
 

As crude as it may sound, you could probably reduce those pivot widths slightly using a small pin vice, some hard wood and some Autosol or similar. Just as you would do to manually polish a wheel pivot by hand without using a lathe. 

I did a bit of pivot reduction with some 2000 grit paper held between tweezer tips. Definite improvement seen although I believe I need to go further. 10 minutes after full wind, DU/DD 267 degrees (0 SPD), vertical typically 215 degrees, -55 SPD. Rate recovery when switching back to horizontal is also much quicker.

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18 hours ago, steve1811uk said:

Also I measured amplitude of the new balance, initially 270 ish, then 10 minutes after full wind, DU/DD 240 degrees 

 

Am I understanding this correct? with a full wind, within 10min you see 30degrees drop. 

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5 minutes ago, Nucejoe said:

Am I understanding this correct? with a full wind, within 10min you see 30degrees drop. 

Yes, but to be honest it would drop 30 degrees within a minute or so. Pivots have been found to be too wide when compared with the old balance. Situation is improving after reducing the pivot diameter a touch. More room for improvement though. Old balance worked pretty much perfect by the way with good amplitude and match between horizontal and vertical. That just had a flat pivot causing a 15 seconds difference between dial up and down.

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Combined effect of weak mainspring and bit of jewels issue is a possibility.     

  Before removing more pivot material , I check both jewels under high magnifiction, you might end up moving too much before you know it plus it is nearly impossible to equally reduce both pivots, not with sand paper anyway.

 

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2 hours ago, steve1811uk said:

I did a bit of pivot reduction with some 2000 grit paper held between tweezer tips. Definite improvement seen although I believe I need to go further. 10 minutes after full wind, DU/DD 267 degrees (0 SPD), vertical typically 215 degrees, -55 SPD. Rate recovery when switching back to horizontal is also much quicker.

That's impressive stuff. You'll ideally also want to polish after sanding, so if you don't have a polish suitable for steel then Brasso whould work well. Make sure the pivots are spotless before refitting or you may turn your jewels abrasive.

Did you ever run your balance DU/DD wit the amplitiude at ~215 degrees to obseve the rate? It's not something which helps your investigation here specifically, but a good test to perform to help your general understanding of how oscillators perform and in particular this example which has issues.

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4 hours ago, steve1811uk said:

That just had a flat pivot causing a 15 seconds difference between dial up and down.

in your reference the flat you mean on the end? Balance pivots are an interesting design on the side you want to reduce friction but on the end it's needed. Okay it's sort of needed. To understand this go to the link below scroll down to the section titled Joseph School of Watch Making. Then while you're there probably download all of them but for this discussion you want to download "Unit 4 - Burnishing Balance Pivots".

then carefully read the text in the beginning it tells you a lot about the pivots. Look very carefully at the drawings you'll notice that the balance hole jewel is shaped differently then most train jewels. The reason I use the word most is on high grade watches all of the jewels will look like this. The balance jewels are slightly rounded to reduce the side friction. Then as you still have too much friction to equalize at the end of the pivots needs to be slightly flat.

10 tests you should do is when the balance wheels in the watch without the pallet fork and hairspring. Given a puff of air with your blower and watch its spin it should spin effortlessly. Then while its spinning rotate the movement around slowly. Because once the balance wheel spinning effortlessly it should spin in all directions of the movement and rotating around without coming to a stop. This is where your microscopes are fine but the reality of what the balance wheel does in the watches what you want to have illegally microscope your clearances seemed fine but a real life there too tight your balance wheels not going to spin.

Joseph School of Watch Making

https://mybulova.com/vintage-bulova-catalogs

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On 11/15/2020 at 7:46 PM, JohnR725 said:

in your reference the flat you mean on the end? Balance pivots are an interesting design on the side you want to reduce friction but on the end it's needed. Okay it's sort of needed. To understand this go to the link below scroll down to the section titled Joseph School of Watch Making. Then while you're there probably download all of them but for this discussion you want to download "Unit 4 - Burnishing Balance Pivots".

then carefully read the text in the beginning it tells you a lot about the pivots. Look very carefully at the drawings you'll notice that the balance hole jewel is shaped differently then most train jewels. The reason I use the word most is on high grade watches all of the jewels will look like this. The balance jewels are slightly rounded to reduce the side friction. Then as you still have too much friction to equalize at the end of the pivots needs to be slightly flat.

10 tests you should do is when the balance wheels in the watch without the pallet fork and hairspring. Given a puff of air with your blower and watch its spin it should spin effortlessly. Then while its spinning rotate the movement around slowly. Because once the balance wheel spinning effortlessly it should spin in all directions of the movement and rotating around without coming to a stop. This is where your microscopes are fine but the reality of what the balance wheel does in the watches what you want to have illegally microscope your clearances seemed fine but a real life there too tight your balance wheels not going to spin.

Joseph School of Watch Making

https://mybulova.com/vintage-bulova-catalogs

Hi John, Thank you for the link which is very interesting. Unfortunately I managed to break off the pivot. To be honest with you I thought that was likely to happen, trying to work without the proper tools for the job was always going to be fraught with danger. For now I will keep an eye out for a Seiko balance complete at a reasonable price (£20 - 25 or thereabouts) or hopefully find someone who can reduce the pivot diameter on the two remaining Renata balances that I have here (both have pivots that are too wide). This hobby can be so rewarding but in some ways very frustrating. Steve.

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in addition to looking for balance complete if you look at that list I gave you of other watches you can look for other Seiko watches that have the same balance complete. Although it's always disturbing when you find a complete watch just to steal one part from it. Seems like it be nice to find a broken watch the steal the part from.

then if you had a lathe not always 100% needed but nice to have if you are changing a balance staff. Then you can just change the balance staff in this watch. Of course you need a few more tools but this is watch repair you always need a few more tools don't worry you're never going to reach the end of when you need tools.

other options just because

this is an interesting video he's not using the classical bow to power the tool which is probably helpful. it's an interesting tool and it would help you with your problem but it takes a lot of practice to do it right. ey're broken

https://youtu.be/uktGMlwthlY

as usual in watch repair people are resourceful other tools like this one. Yes you can reduce the size the pivots with this and polish them. Not quite as nice as the above tool at least for burnishing but still works.

https://youtu.be/FRR9JSfUtCM

a variation of the above tool with a more practical way to drive it.

https://youtu.be/1uvc6yXBaqk

 

 

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I'm not sure this post of mine belongs in this thread, but as poising was very much discussed in relation to solving the problem (although now ruled out) I hope it's OK!? Otherwise, please feel free to delete this post and I'll publish it in a thread of its own.

I’m trying to get to grips with my understanding of poising before I actually start practicing it, and I would really appreciate your comments on my thoughts which I’ll try to present here. I guess it’s not so much about trying to get answers to basic questions as it is trying to get confirmation or disproof (both equally valuable) of my assumptions and conclusions.

So, as I understand it, and please correct me if I’m wrong, positional errors cannot be attributed to an unpoised balance wheel as long as the amplitude is at 220° at which point any positional errors originating from a heavy spot on the balance is cancelled out. To be sure, we can still have positional errors, we can still have a heavy spot, but we can be sure that at an amplitude of 220° the source of positional errors is something other than a heavy spot, if any, on the balance wheel.

Assuming the above paragraph is correct, I’m puzzled by the video “The Vostok Amphibia Scuba Dude Russian military Watch - Review, teardown and Improvements. Amphibian” by @Mark. 3 minutes and 13 seconds into the video Mark puts the movement on a timing machine. The movement is tested in four positions.
DU: +20@314°,
DD: +40@304°,
PD: -7@314°, and
PL:+35@262°).
At this point Mark correctly concludes that there is a 47 seconds difference between the fastest and the slowest measured rate and goes on to say “We will see if we can improve that”. He doesn’t mention anything about poising the balance at this point in the video, and I guess that makes sense since the movement hasn’t been serviced and deemed faultless, and then tested at around 180° to amplify the effect of a possibly unpoised balance.

26 minutes and 55 seconds into the video Mark says: “Now I need to deal with the huge amount of positional error, and to do this I will be using the Greiner method of dynamic poising.” So, at this point he has obviously already determined that the cause of the positional errors is an unpoised balance, but he doesn’t explain how he came to that conclusion. Not knowing better, I would have assumed that he came to that conclusion from the initial testing of the watch showing a 47 seconds difference!? It would seem to me that he would only run the balance at about 170° to 180° as a method to amplify the positional errors. Not as a means to determine if the balance is unpoised which appears to have been done during the initial testing at more or less full wind?

Looking at the image published by @praezis and the image published by @JohnR725 we can see that the effects of an unpoised balance wheel manifest both above and below 220°. So, perhaps we can indeed draw the conclusion that a balance wheel is unpoised even when tested above 220° as long as all other sources for errors have been ruled out and that the positional errors are large enough to show above 220°?

Again, I’m sort of unsure and I’d be very interested to read your thoughts about this! Thanks!
 

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