Omega 1120 Lift Angle Clarification.

[ClusterFoxtrot]

Good afternoon all,

I have a Seamaster 120 that I am rebuilding and have been using the ETA 2892A2 technical document for data, however, I have come across the actual Omega technical document and when I checked the lift angles, there appears to be a difference. Omega have the lift angle as 53º, ETA as 51º.

Many places on the web also state the lift angle as 51º, so I wondered if anyone here could state definitively what the figure should be, as 2º lift angle delta would potentially have a significant impact on the amplitude reading.

Thanks in advance

[LittleWatchShop]

I do not know the answer, but my analysis indicates that the derivative of Amplitude (A) with respect to lift angle (LA) is approximately A/LA. so with a nominal amplitude of 260 degrees at a nominal lift angle of 52 degrees, the derivative is 5.  Therefore, for every degree variance of LA, you would expect an amplitude change of 5 degrees. 

So your range of possible lift angles yield a range of amplitudes of only 10 degrees (260 +/- 5). I would not call that significant.

I measure amplitude using my smart phone in super slow motion video.

[ClusterFoxtrot]

39 minutes ago, LittleWatchShop said:

I measure amplitude using my smart phone in super slow motion video.

That's an interesting use of technology.

[JohnR725]

17 hours ago, ClusterFoxtrot said:

Omega have the lift angle as 53º, ETA as 51º.

always fun when a variety of sources even from the same manufacturer don't seem to agree? The Omega document I have on timing specifications for the 1120a is 51°. Then for the eta I also see it's 51°. just as I was curious I went too much newer version of Omega it's still 51°.

 

[ClusterFoxtrot]

It's entirely possible that there has been a revision to the document, which in fairness, is quite old and there was a typo.

[JohnR725]

On 7/17/2023 at 9:52 AM, ClusterFoxtrot said:

if anyone here could state definitively what the figure should be, as 2º lift angle delta would potentially have a significant impact on the amplitude reading.

I really doubt that 2° make that much of a difference but if it does You should watch this video he explains how to figure out the lift angle for yourself and then you'll know exactly what it is for your watch.

 

On 8/31/2023 at 12:10 PM, ClusterFoxtrot said:

It's entirely possible that there has been a revision to the document, which in fairness, is quite old and there was a typo.

So which document are we talking about that's quite old? I made a reference to the documentation I was looking at I didn't say which one I was looking at. Then for an air of this type how fast with the noticed a problem? Then you'll notice in some of the images I'm giving you things are highlighted if we looked at the back of a document it would be a reference to those of the updates from the previous version so yes the really do update the documentation.

what you need is something called WORKING INSTRUCTION N° 28   25.11.2020. Yes 2020 is really old but if they haven't figured out there problem by now they probably never will.

Now to explain why you're only getting snippets out of the documentation the only way you can get this is you have to have Swatch group access yourself or find something that does have Swatch group access it's not available as far as I know anywhere that you can download. Then Swatch group is paranoid with the documentation let's give an example from when they used to give some documentation out that cousins have

So seeing as how every single document downloaded office watch group as a watermark in the corner complete with the data is downloaded etc. how would they feel if somebody just distributed the world? You know what a pain in the ass it is to get anybody that even has a Swatch group access so know you're never going to see the whole document best your analyses of somebody kindly snips out images Trying to avoid the watermark

So for an 1120 in the image below its programmed number eight. It's chronometer grade watch there is the frequency and the 200 is the amplitude at 24 hours. The plus -10 is when the calendar should change in other words you calendars should change within 10 minutes of midnight. The 44 is therunning time and I could care less about the number two as I'd have to go and look up what it actually means.

Now let's go find the programs I don't really like the newer documents to things are fragmented versus the old stuff which will see below

 

 Now this is weird 2016 I'm not seeing your watch? November 2017 it shows up and looks like it's 51°.

Now if you're not seeing the amplitude you perceive you're seeing with the correct 51° they really should look at how your measuring or amplitude? If you're using anything that resembles phone apps are apps that do not use a standard watch type pickup that lead the problems sometimes with watches are in heavy cases the case will have a dampening effect that can have issues

but no matter what it looks like 51°

 

Edited September 2, 2023 by JohnR725

[JohnR725]

On 7/18/2023 at 3:33 AM, JohnR725 said:

specifications for the 1120a is 51°.

I had almost forgot about this when I went to work on Thursday the laptop I normally use at 1120 tech sheet up and noticed something 53°. How sad that conflicts with the newer documentation.

In real life 51 or 53° is going to really matter that much at all. Especially since nobody cares what the maximum amplitude is all Omega cares about is the amplitude at 24 hours