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diamondslayer

Timing and Lift Angle!!

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I just learned when timing a watch you must know the lift angle! I found the LA for my Tissot Seastar with a 2824-2 movement. It is 50 and I have been timing it at 52 which gave me an average of -10.2 s/d in 5positions fully wound. When I adjusted the LA and retimed it I had a delta of 5 and it now averages +2.2 s/d in five positions fully wound. What a difference knowing the lift angle can make.

I also found know a way to find the LA when you can't find it or there is no more info on it. All you have to do is find 180 amp manually and then you can find the LA. it's not easy, but it works.

5a817e719ff838f200edf7cd3e7f91b2.jpg

Diamondslayer

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37 minutes ago, diamondslayer said:

I just learned when timing a watch you must know the lift angle! I found the LA for my Tissot Seastar with a 2824-2 movement. It is 50 and I have been timing it at 52 which gave me an average of -10.2 s/d in 5positions fully wound. When I adjusted the LA and retimed it I had a delta of 5 and it now averages +2.2 s/d in five positions fully wound. What a difference knowing the lift angle can make.

Timegrapher's lift angle does not affect timing. Timing is obtained by direct comparison to the internal oscillator. Lift angle only affects amplitude, and not by a big amaount either.

See: 

 

Note how the video posted uses an empirical method based on visually bringing the movement to a reference amplitude (180) and then adjusting the angle until read amplitude matches. Rightly, timing is timing is never mentioned and it's not a factor.

 Also, do not regulate a  and disregard whatever value with the movement fully found. Wait at least 10 mins or better an hour.

 

 

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5 minutes ago, diamondslayer said:

I started using this technique and it has helped me improve timing altogether. I'm finding that the LA is very important in timing,

It is not. Check pics below, correct lift angle would be 53, but either 50 or 56 is set, no significant difference.

 

P7303181.JPG

P7303180.JPG

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11 minutes ago, diamondslayer said:

 

You could be reading a knock on amp if your LR IS wrong. And you can find poising problems easier and more accurate.

It's not so. Having set a wrong lift angle does not generate false knocks. Also it has nothing to with balance poising.
All it does  it to allow correct calculation of amplitude. It does not intervene at all in pattern, timing, or beat error.

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Unfortunately when I acquired a timegrapher I was told knowing the correct lift angle was necessary to make accurate adjustments. JDM on a previous thread demonstrated to me that the LA has no practical significance on beat error and therefore timing.

If the LA is set to 52° on the timegrapher, excellent results can be achieved in the aid of timing a watch. Always remembering most movements show a variation, according to the position the watch is in anyway.

Now I tend to watch what those little dotted lines are doing, rather than what the LA is.

Sent from my SM-G920F using Tapatalk

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About false knocks. Depending on the strength of the spurious noise relative to the impulse noise, the machine can detect noises that are not there, or not major. In this case one can lower a little the gain using the down button, which is there for this purpose. The idea is not to to hide issues, but red herrings.

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It's not so. Having set a wrong lift angle does not generate false knocks. Also it has nothing to with balance poising.

All it does  it to allow correct calculation of amplitude. It does not intervene at all in pattern, timing, or beat error.

What if your amp is reading 340 because the LA is wrong? Amp should be no higher then 315-330, but 330 is a lot. Maybe I'm wrong on poising?

Diamondslayer

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Just now, diamondslayer said:

What if your amp is reading 340 because the LA is wrong? Amp should be no higher then 315-330, but 330 is a lot. 

I have seen only one Seiko 6R15 reading at 330°, for few seconds right after full charge, and posted about it as a curiosity. For a Seiko it's a lot, but not so expreme a Swiss movement.

Consider that Seiko lift angle is 53 °, while the machine always defaults at 52 °. That's a very small difference, and so is the derived error in calculating amplitude. I do not have a chart that shows how this error progress, but I can certainly make one based on observation.

 

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I have seen only one Seiko 6R15 reading at 330°, for few seconds right after full charge, and posted about it as a curiosity. For a Seiko it's a lot, but not so expreme a Swiss movement.

Consider that Seiko lift angle is 53 °, while the machine always defaults at 52 °. That's a very small difference, and so is the derived error in calculating amplitude. I do not have a chart that shows how this error progress, but I can certainly make one based on observation.

 

If your amp is not right due to wrong LA, you can't accurately find the disturbances in poising. You have to read correct amp to find impulse and resistance. Whether it is above 220 or below. You have to have an accurate reading of 180 amp to find faults too! You have to have an amp of 160-180 to get accurate results to dynamic poise. If that is off poising won't be as accurate.

Amplitude needs to be correct to spot these faults. Cleanliness, lubrication, endshakes, centering of the hairspring, pallet jewels set too deep, weak mainspring/mainspring shape, hands rubbing, pivots/shape and condition, bent center tube, train wheel freedom.

If you have a watch that has a LA 44, then 52 is going to be way off! ETA 6497-1 finding faults is going to be too hard.

Diamondslayer

I was wrong on 330 amp being the highest. It is 300 to 315. 330 is way to high.

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5 minutes ago, diamondslayer said:

You have to have an accurate reading of 180 amp to find faults too! You have to have an amp of 160-180 to get accurate results to dynamic poise. If that is off poising won't be as accurate.

Do you have a link to a book or online resource / guide about balance poising? Have you done any work on that which you can show us?

Edited by jdm

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1 hour ago, diamondslayer said:

 

If your amp is right you know if your watch is or is not knocking. You could be reading a knock on amp if your LR IS wrong. And you can find poising problems easier and more accurate. Just to name a few.

 

Diamondslayer

I find terminology and watch repair very interesting. Depending upon location and when whatever it is you're looking at was written we can have different terminology for the same thing. So knocking Is also called Rebanking. I have a link to a nice video which shows what it is.

https://www.youtube.com/watch?v=Rcqrb3_vin8

List of lift angles

http://pczw.uhren-mikl.com/downloads/gamma.pdf

Timing machine information and where lift angle comes from

http://www.witschi.com/assets/files/sheets/Test and measuring technology mechanical watches.pdf

Then I have an image of how timing machines figure out what Amplitude is.

cal amp.JPG

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24 minutes ago, diamondslayer said:

 

 

If your amp is not right due to wrong LA, you can't accurately find the disturbances in poising. You have to read correct amp to find impulse and resistance. Whether it is above 220 or below. You have to have an accurate reading of 180 amp to find faults too! You have to have an amp of 160-180 to get accurate results to dynamic poise. If that is off poising won't be as accurate.

 

Amplitude needs to be correct to spot these faults. Cleanliness, lubrication, endshakes, centering of the hairspring, pallet jewels set too deep, weak mainspring/mainspring shape, hands rubbing, pivots/shape and condition, bent center tube, train wheel freedom.

 

If you have a watch that has a LA 44, then 52 is going to be way off! ETA 6497-1 finding faults is going to be too hard.

 

Diamondslayer

I was wrong on 330 amp being the highest. It is 300 to 315. 330 is way to high.

I think you're going to find you don't have to be that exact on this. I've attached an image to explain about the poising problem. So as you can see from the Image the lower the amplitude the greater the effect of positional errors. Then as you approach 220 positional errors are no longer a problem. Then as you go over 220° positional errors are less of a problem. This is why it be nice if your watch was always running at least 220 or higher it minimizes positional errors.

As far as faultfinding goes and the amplitude has to be correct I would really like to see some examples where having incorrect amplitude prevents you from doing any of these. Most users of timing machines leave them at the default 52°. Then what about the days of the paper tape machine they didn't even have the lift angle only a paper graphical display?

 

 

 

amp timing.JPG

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Which lift angle should one adopt for the ETA 2824 movement?

 

ETA Technical Communication for the first 2824 movements state the LA to be 53 degrees.

 

ETA 1981 Technical Communication for the 2824-1 movement states the LA to be 53 degrees.

 

ETA Technical Communication for 2824-2 movements state the LA to be 50 degrees. But I see on the web and various 'how to' instruction videos, a lift angle of 53 degrees is keyed into timgraphers. Therefore, have most people been using the wrong lift angle setting of 53 degrees with their timegraphers, when it should be 50 degrees for ETA 2824-2 movements?

 

I just serviced an original 2824 and assumed the LA to be that referenced in ETA Technical Communication for 2824-2. One can see this in my other post here:

 

 

So I'll now re-time the movement with a list angle of 53 degrees, which it should be for the older ETA 2824 version. Come to think about it, I did do that to start with and the amplitude was far better.

Hmmm! very interesting.

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8 hours ago, systeman said:

So I'll now re-time the movement with a list angle of 53 degrees, which it should be for the older ETA 2824 version. Come to think about it, I did do that to start with and the amplitude was far better.

I don't know what the correct value is, but you never re-time a mov.t based on the lift angle, which has no influence whatsoever on rate and beat error.

Only amplitude  is influenced, by about 1.5 deg of instrument reading for each one of lift angle, but since amplitude can vary easily by 5 - 10 deg depending on power charge and position, that is also negligible.

Now, this discussion has been had already, complete with formulas and experimental confirmation, as soon I can find the original thread I'll merge this one into it.

 

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Apologies if this question should have been started in a new thread, but I think it is related to the essence of the current one....

I have been working on an ETA2404 nicely branded as Accurist. The watch came to me very dirt and running fast, mostly due to a dusty and untrue oscillator hs . After rectifying the hs back to a true shape I checked the approximate accuracy of beat setup by inserting the oscillator assembly/cock in the main plate only, and affirmed that the roller jewel was close to mid banks when at rest. I then cleaned, rebuilt and lubricated the movt. I decided to place a small black pen mark on the rim of the oscillator in order to check the angle of arc with slow motion video and compare my findings to the recommendations here of 315 to 340 degrees. I was astonished to find the oscillator was rotating approx 400 degrees in total (ie swing of +\- 200). How can this be possible please? I’ve been pulling my hair out trying to fathom this. Would re-banking not occur and prevent such an angle? Watch is now keeping good time and sounds healthy to my amateur ear (no galloping or strange knocks). Any help or explanation will be much appreciated please.

I look forward to hearing from you.


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On 7/31/2016 at 1:32 AM, JohnR725 said:

amp timing.JPG

@John
your picture shows even more: If you try to poise at >220 deg, you will make the error worse, as the effect of poise error is inverted there.

@diamondslayer
There is no danger at all using 52 lift angle with poising: if the real L.A. is e.g. 42 (pocket watch, chronograph etc),  you will poise at a lower amplitude than expected. This just amplifies the visible rate differences in vertcal posirions!

Frank

Edited by praezis

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Apologies if this question should have been started in a new thread, but I think it is related to the essence of the current one....

I have been working on an ETA2404 nicely branded as Accurist. The watch came to me very dirt and running fast, mostly due to a dusty and untrue oscillator hs . After rectifying the hs back to a true shape I checked the approximate accuracy of beat setup by inserting the oscillator assembly/cock in the main plate only, and affirmed that the roller jewel was close to mid banks when at rest. I then cleaned, rebuilt and lubricated the movt. I decided to place a small black pen mark on the rim of the oscillator in order to check the angle of arc with slow motion video and compare my findings to the recommendations here of 315 to 340 degrees. I was astonished to find the oscillator was rotating approx 400 degrees in total (ie swing of +\- 200). How can this be possible please? I’ve been pulling my hair out trying to fathom this. Would re-banking not occur and prevent such an angle? Watch is now keeping good time and sounds healthy to my amateur ear (no galloping or strange knocks). Any help or explanation will be much appreciated please.

I look forward to hearing from you.


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All sorted in my understanding. I drew this out on paper, and after paying particular attention to videos and articles I found on the topic, I now see where I was going wrong in my thought process. Kind regards.


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