Acceptable amplitude difference between positions

[Bonzer]

What would be the maximum acceptable amplitude difference between horizontal and vertical positions? 

I have a movement that differs by about 50 degrees which probably indicates there may be some issue, but would be interested to know what is normal and not.

Thanks.

[JohnR725]

8 hours ago, Bonzer said:

What would be the maximum acceptable amplitude difference between horizontal and vertical positions? 

I have a movement that differs by about 50 degrees which probably indicates there may be some issue, but would be interested to know what is normal and not.

way too many variables here to even make a guess.

size the watch will make a difference ladies watch pocket watch for instance. Condition of the watch has it ever been serviced what is its current amplitude so in other words adapted really sucks need to serviced then it would be much greater. Quality the watch modern versus vintage. A whole bunch of things can make it a challenge to have an absolute this is good versus bad situation.

than usually if you're looking at technical specs from watch companies they are more concerned about timekeeping in various positions. they're usually not obsessed with amplitude other than at 24 hours and if the watch still keeps time.

I snipped out something from the witschi technical PDF which I attached there is what they think should happen. But they sometimes tend to have a more idealized world of things average modern watches in good condition not vintage watches for instance.

 

 

Witschi Training Course.pdf

[VWatchie]

That chart is very interesting @JohnR725 in the respect that reading many posts on this forum you get the impression that an amplitude below about 270 degrees in the horizontal position (fully wound) should be considered a failure.

I've serviced a few watches now since I started this hobby some five years ago. Very often I have found the amplitude to be somewhat below 270 degrees and I have always thought of that as a failure (which has been very disappointing at times). Still, many of those watches have proved to be excellent timekeepers despite not being able to reach an amplitude above 270 degrees.

So, through practical experience, I have learned not to overestimate the importance of high amplitude. If you think that amplitude is all-important, you probably get tired of repairing and servicing watches pretty quickly.

[gbyleveldt]

Heh, till you work on Seiko 6309's where you're considered a master of the art if you get 230deg amplitude. It really depends on the piece and how it was designed

[JohnR725]

2 hours ago, VWatchie said:

in the respect that reading many posts on this forum you get the impression that an amplitude below about 270 degrees in the horizontal position (fully wound) should be considered a failure.

yes that's one of the amusements with this group an obsession with amplitude.

1 hour ago, gbyleveldt said:

Heh, till you work on Seiko 6309's where you're considered a master of the art if you get 230deg amplitude. It really depends on the piece and how it was designed

obviously nobody from Seiko factories ever on this group they would be so unhappy their watches totally suck for amplitude at least according to group specifications. Notice how normally and never find a Seiko referenced amplitude except the 4006 a manual specifies fully wound up you should have a minimum of what?

typically for the watch companies if they have specifications are concerned if they have too much amplitude like over 300+ degrees otherwise they could care less until 24 hours later. Then it's supposed to have a minimum but the big thing they want is time keeping.

So while Omega specifications are almost everything they have a section on vintage watches not found in the normal specifications and I snipped out that image. Notice the minimum amplitudes I'm not sure I want to say what those minimums are because somebody's go find some tar and feather and track me down for daring to suggest a watch could even run at those amplitudes. On the other hand these are Omega watches which are usually really really nice other watches probably would keep horrible time of those amplitudes but still it tells us that they don't care about amplitude wound up the only care about timekeeping amplitude at 24 hours

then taking a quick look at the rest the Omega timing sheets looks like the highest of the low amplitude is 200° and the low as 160 and then it just depends on the watch it could be as I said 160, 170, 180, 190 and then 200 But there's no specification that says you've done a good job if you watch is doing 271.9° I'm just joking about that particular number but that's not in the specifications.

Realistically it seems to me that if the watch was running before you cleaned that if you ran a timing profile and if afterwords it was doing better amplitude and preferably better timekeeping you did good enough at the end of 24 hours it still running and keeping reasonable time than you did outstanding.

[Bonzer]

Thanks for the replies and advice @JohnR725 and @VWatchie and also for the charts.

 

1 hour ago, JohnR725 said:

Realistically it seems to me that if the watch was running before you cleaned that if you ran a timing profile and if afterwords it was doing better amplitude and preferably better timekeeping you did good enough at the end of 24 hours it still running and keeping reasonable time than you did outstanding.

Happily, this particular movement falls within the above specification as it was running pretty awful prior to a service. I've also had to poise the balance to stop some horrendous rate changes and all is a lot better now.

I agree with @gbyleveldtabout the Seiko's. I've never been able to get my 6309's to run much above 230. I've had to learn to be happy with that.

[VWatchie]

9 hours ago, JohnR725 said:

Realistically it seems to me that if the watch was running before you cleaned that if you ran a timing profile and if afterwords it was doing better amplitude and preferably better timekeeping you did good enough at the end of 24 hours it still running and keeping reasonable time than you did outstanding.

 

I just had to quote these words of wisdom as well.

[mikepilk]

My "acceptable amplitude" for older, well used watches, is about 240°

I agree with @gbyleveldt and @Bonzer about Seiko's, where I consider 230° as good !

[jdm]

On 8/19/2022 at 12:05 AM, Bonzer said:

I have a movement that differs by about 50 degrees which probably indicates there may be some issue, but would be interested to know what is normal and not.

Definitely not acceptable. You asked about what is an acceptable difference but got answers about absolute values, instead I'd like to point out that a difference above 10deg should raise suspicions, no matter the maker and type.

[VWatchie]

On 8/19/2022 at 12:05 AM, Bonzer said:

What would be the maximum acceptable amplitude difference between horizontal and vertical positions? 

On 8/20/2022 at 9:56 PM, jdm said:

I'd like to point out that a difference above 10deg should raise suspicions, no matter the maker and type.

I don't think I ever saw a movement having a difference of fewer than 10 degrees. Among the best I've ever seen in any of my watches is an ETA 2824-2 in a Sinn 556 A watch which I haven't even serviced. Pictures of the TM here. Anyway, if you manage to get even "better" results it would be interesting to hear more about it. What kind of suspicions?

[mikepilk]

On 8/20/2022 at 8:56 PM, jdm said:

Definitely not acceptable. You asked about what is an acceptable difference but got answers about absolute values, instead I'd like to point out that a difference above 10deg should raise suspicions, no matter the maker and type.

Me too @VWatchie - I don't think I've ever had a watch with less than 10° difference between vertical and horizontal. I would say that about 20° was more typical of a 'good' watch. I'd say that 10 would be the limit between  DU and DD.  (But I am just a home tinkerer)

Edited August 21, 2022 by mikepilk

[Gramham]

Hello @mikepilk,

I may have some helpful information, though from a purely theoretical perspective.  I just watched a video over at ChronoGlide where the stated difference in friction between pivots in line with the center of the Earth (i.e. Dial Up, Dial Down) and when at right angles to the center of the earth (Pendulum Up, Pendulum Down, Pendulum Left, Pendulum Right) was in the order of 800%.

This makes sense when you consider the amount of surface area of the pivot coming into contact with the amount of bearing surface area that it has been set in (brass or jewel).  In de Carle (1981, pp. 196-197) there appears a discussion of the proper shape of the end of a pivot, as well as a couple methods of polishing the end of a pivot, one manual and one machine-based that relies on the use of something called a Jacot Tool.

Could it be simply that your pivot ends are rough from corrosion, which is affecting effective transmission of impulse energy through the train of gears? 

Have you inspected the pivots and bearings for rough surfacing under a microscope?  Are they sufficiently polished?

I include screen shots of the above-mentioned sections of the book for your convenience:

 

Forgive me if you know all of this stuff already, I am just trying to be helpful. 

g.
----

REFERENCES

de Carle, D (1981) CLOCK AND WATCH REPAIRING (2nd Edition), London: Robert Hale (ISBN:  0-7091-9436-6).
https://www.gettextbooks.com/isbn/9780719803802/
 

Edited August 21, 2022 by Gramham
Removed extra spacing line

[Bonzer]

Thanks for the excellent info.

The pivots look ok under my microscope but they haven't been polished as I don't have the means to do that yet so it may well be that this is where the issue is.

 

Thanks @Gramham

[Gramham]

3 hours ago, Bonzer said:

Thanks for the excellent info.

The pivots look ok under my microscope but they haven't been polished as I don't have the means to do that yet so it may well be that this is where the issue is.

 

Thanks @Gramham

Hello @Bonzer

I just watched a refurb video done on a french 8-day where the pivots were polished with a device held in a pin vice. 

Maybe the more expert among us can identify what is being used (e-flex?  Inflex?)

It must be very low cost...when compared to the cost of a Jacot tool!

I can't quite make out what he's saying at 13:15 but maybe you or someone else can...
 

 

g.
----

 

[gbyleveldt]

Eveflex, I use it as well. It’s a pin polisher. I use it to clean the pivots using the softest one. It’s not a Jacot tool (which is on another level of polishing) but I use it to mostly remove Epilame from treated pivots

[VWatchie]

On 8/24/2022 at 4:37 AM, gbyleveldt said:

Eveflex, I use it as well. It’s a pin polisher. I use it to clean the pivots using the softest one. It’s not a Jacot tool (which is on another level of polishing) but I use it to mostly remove Epilame from treated pivots

I just recently tried these polishes (see the link below) and was very happy with the results. However, one must be very careful in the choice of polisher because they have an abrasive effect. The softest one is the way to go.

https://www.watchrepairtalk.com/topic/13969-slow-moving-escape-wheel/#comment-197991

[mikepilk]

I had a look to see If I could find any numbers in service sheets for allowable differences between amplitudes - couldn't find any. 

I have an Omega Workshop Guide on "BASIC CHECKS AND SETTINGS OF A MECHANICAL WATCH" - the Amplitude tolerances are in WI 28 , which I don't have. 

On the website "Adjusting Vintage Watches" https://adjustingvintagewatches.com/dynamic-poising-3-vertical-rates/

Those are the sorts of numbers I'd expect, which suggests that 50 deg difference is OK.

 

[Neverenoughwatches]

On 8/24/2022 at 1:31 AM, Gramham said:

Hello @Bonzer

I just watched a refurb video done on a french 8-day where the pivots were polished with a device held in a pin vice. 

Maybe the more expert among us can identify what is being used (e-flex?  Inflex?)

It must be very low cost...when compared to the cost of a Jacot tool!

I can't quite make out what he's saying at 13:15 but maybe you or someone else can...
 

 

g.
----

 

That barrel is huge. Now thats the sort of mainspring you want to put in by hand

[nickelsilver]

45 minutes ago, mikepilk said:

I had a look to see If I could find any numbers in service sheets for allowable differences between amplitudes - couldn't find any. 

I have an Omega Workshop Guide on "BASIC CHECKS AND SETTINGS OF A MECHANICAL WATCH" - the Amplitude tolerances are in WI 28 , which I don't have. 

On the website "Adjusting Vintage Watches" https://adjustingvintagewatches.com/dynamic-poising-3-vertical-rates/

Those are the sorts of numbers I'd expect, which suggests that 50 deg difference is OK.

 

When I was doing watches for Christophe Claret they wanted min 270 flat, 240 vertical at full wind. It does depend a lot on the caliber, as mentioned above by John.

 

I did an AS 1012 a few years ago that had a 100 degree drop between horizontal and vertical. As a project I tried everything to get it closer: changed pallet fork jewels to olive hole convex; same for balance (it had flat jewels); made new fork arbor with closer fit to jewels (this had helped in other cases, not here); made 2 new staffs- one I progessively reduced the pivot size by a few microns several times to see if the reduced contact area helped, then another to replace it with normal pivots (neither was better than original). Of course the escapement was adjusted to the barest locks- excessive lock shows up more in vertical positions as reduced amplitude. I know that was a popular caliber and tons were produced, but the couple others that have come across the bench performed about the same as the "project" watch. It's a matter of proportions and limits at reduced size: I regularly see 7750 chronos that have around 15 degree drop from hor to vert; just did one that's old enough to be marked "VAL" on the mainplate that still performs to that level (and 8s delta in 6 positions!).

 

One quibble with the quote from Adjusting Vintage Watches- which is a great reference- is that at 220 degrees poise errors are almost completely nullified. So your watch might look amazing in 6 positions, but when the amplitude drops to 200 or climbs to 240 suddenly the timing is off. When I dynamic poise I will let the power down to hit 200 if the watch is maxing at 220.

Edited August 25, 2022 by nickelsilver

[JohnR725]

21 minutes ago, mikepilk said:

Amplitude tolerances are in WI 28 , which I don't have.

The reason you don't have this is because it's not out in the open. If you notice the modern or relatively modern Omega documents or for that matter a lot of Swatch group documents. Every single corner is watermarked with whoever downloaded the document. It makes you wonder if maybe there paranoid over who is releasing the documentation out in the wild as there must be a reason they do that? So it would stand the reason that anyone that has access to Swatch group documentation is not going to release anything that's going to get back to them. 

But if you notice up above I quoted something from Omega the images that comes out of working instruction 28 so if you of a specific caliber that could be snipped out.

30 minutes ago, mikepilk said:

I had a look to see If I could find any numbers in service sheets for allowable differences between amplitudes - couldn't find any. 

The problem is with the various watch companies that put all the stuff in various places. Some of them have them in separate sheets for just timing specifications others have specific documents and some included in with the normal technical .So for instance eta has their timing information in their manufacturing information sheets. I'm attaching one of them and I snipped out an image.

The reasons there's two separate specifications is it's for the various grades of this watch. So timing specifications are greater and they had one more position for checking the watch In. The notice for amplitude the concerned about it when it's fully wound up and the minimum At 24 hours.

 

ETA 6497-1 Manufacturing Information.pdf

[mikepilk]

1 hour ago, nickelsilver said:

One quibble with the quote from Adjusting Vintage Watches- which is a great reference- is that at 220 degrees poise errors are almost completely nullified. So your watch might look amazing in 6 positions, but when the amplitude drops to 200 or climbs to 240 suddenly the timing is off. When I dynamic poise I will let the power down to hit 200 if the watch is maxing at 220.

He does point this on on Adjusting Vintage Watches and suggests 140-160° for dynamic poising. It's a site worth reading if you want info on dynamic poising.

I serviced a Rolex 2230 (small ladies watch, 20mm dia) for a friend. It was very stable in all positions - DU/DD 300°, but all vertical positions about 250°.

[praezis]

4 hours ago, nickelsilver said:

that at 220 degrees poise errors are almost completely nullified. So your watch might look amazing in 6 positions, but when the amplitude drops to 200 or climbs to 240 suddenly the timing is off.

Surely it wouldn't be wise to poise at 220° (but satisfying ).

Amplitude is not a matter of numbers chasing. Classic numbers are 270° horizontal and 220-240 vertical.
Why?
At 220 (vertical position!) the poise error is about zero, as mentioned by nickelsilver. But even in the vicinity this error will be low.
At 270 (horizontal position!) a poise error would show - but we are horizontal! 

All this can be read from the underlying Bessel function:
 Influence of a heavy spot below center

Frank

Edited August 25, 2022 by praezis

[nickelsilver]

2 hours ago, mikepilk said:

He does point this on on Adjusting Vintage Watches and suggests 140-160° for dynamic poising. It's a site worth reading if you want info on dynamic poising.

I serviced a Rolex 2230 (small ladies watch, 20mm dia) for a friend. It was very stable in all positions - DU/DD 300°, but all vertical positions about 250°.

It's definitely worth reading- been a while since I dug through it and should have assumed he addressed that.

 

It seems dynamic poise is like a lot of things in watchmaking, folks approach it differently to obtain the same results. I'm a fan of doing it at amplitudes above 220 if the watch allows, and I always do 8 vertical positions. A friend, who's really good at timing, does 4 positions, amplitude depending on watch (I think he favors higher amplitude too). The big catch, and I've been caught, haha, is the heavy spot reverses between over 220 and under 220. Over 220 heavy spot is at the bottom in the slow position.

 

I think your amplitudes on that Rolex look great.

[mikepilk]

11 minutes ago, nickelsilver said:

The big catch, and I've been caught, haha, is the heavy spot reverses between over 220 and under 220. Over 220 heavy spot is at the bottom in the slow position.

That's one that can catch you out. On this page  https://adjustingvintagewatches.com/dynamic-poising-3-vertical-rates/ there is a figure that shows how poise errors interact with amplitude to affect rates.

The lower amplitudes show bigger errors than those above 220°