Landeron 48 Beat-Error, Amplitude & Daily rate ......

[Endeavor]

Hello All;

In my Landeron48 restoration walk-through I posted a question; but so far no reply. Perhaps it is too much embedded in the long thread (?). Try again under "Advice";

Having no experiences at all in 50 - 60 years old movements, and no idea what to expect, I was a bit disappointed in seeing, just after the motion-works were back together, the following graphs (Note the lifting angle is slightly off and please ignore the odd off-line dots; these are most likely the Watch-o-Scope picking up interference);

The movement was adjusted on Dial Down;

Dial UP;

Crown Down;

Crown Up;

Questions are;

1) How good or bad is the general picture?

2) Is it worth trying to adjust the beat-error? To do this the hair-spring collet on the balance staff has to be rotated ......which is "slightly" tricky, to say the least considering the collet seems tight on the staff.

3) Considering a brand new main-spring is installed, the amplitude isn't the highest I've ever seen .......?

Is this "good" / "normal" for a 50 - 60 year old movement or is it a scrapper? Any suggestion how to proceed?

Are there some doctors in the room who can provide me with a health report or some uplifting comments? Highly appreciated !

 

Edited February 23, 2017 by Endeavor

[JohnR725]

The lift angle you're showing is 51° by slightly off are you aware that it's around 42°? Link below for the lift angle.

So I assume the timing results are with chronograph functions not being driven?

Dial down is interesting in that usually when you see a variation in timing it indicates a power loss through the gear train or even the mainspring. So in other words you're not getting even power you'll then see variations in timing. But not see any other dramatic variations in all the rest your printouts? I see a little bit of variation but you're always going to have that the older watches. This is where if you are concerned about something like this running a long time plot may turn up the problem.

Usually dial-up and dial down should be the same for timekeeping I'm wondering if your hairspring is rubbing on something and that's why you're picking up the extra dots and you're running fast perhaps?

The interesting part is the pendant positions at a little less than 200° if the watch is fully wound up is definitely going to be a problem. 24 hours from now is the watch even going to be running? As soon as you add in the chronograph part it's going to rob a little power from the gear train and if you don't have enough power to run your watch. I noticed in the walk-through references to Rust perhaps? You want to go back and look at all the pivots and make sure they're shiny and smooth. Rust is interesting In that it actually is a grinding compound. So it's really not something you want on the pivots.

Then yes it would be nice if the Beat was better but I worry about the other stuff first. Plus it be nice if we had four pendant positions but it looks like from the 2 you have a positional error in the balance wheel which I would not worry about until you get the pendant position amplitudes up to something more realistic.

http://hiro.alliancehorlogere.com/en/Under_the_Loupe/Landeron_48.html

[Delgetti]

Hi @Endeavor,

I'm just a beginner, but as far as I know you have to define the lift angle for the timegrapher to get a correct calculated amplitude. I found different tables on the internet which say the lift angle for a Landeron 248 is 42°.

I just purchased a watch with a 248 and will put it on the timegrapher in the evening and reply here which amplitude I found.

[szbalogh]

You have some small amplitude waves in the graphs with a frequency about 1/min suggesting that the minute wheel is not flat or something around there. But this seems a minor issue.

Aplitude DU and DD is ok if it is freshly serviced. It will climb after a few full windings and working days.

My mayor concern is about the bad rate and amplitude change in vertical positions. The reason for this can be worn/dirty pivots/hole jewels and/or distorted hairspring. Too much oil.... 

If the jewels and pivots are ok first check if the hairspring is between the and moving freely between the regulator pins at rest, it is flat and centered?

 

[Endeavor]

The hairspring was in a bit of a mess and indeed it currently isn't fully free at the regulator pins. Sometimes it's good to take a little brake and think about, and ask around what the remedial action(s) should / could be. This weekend I'll try to get the hairspring floating freely between the pins and perhaps that also may change the beat-error for the better (?). Obviously for the next measurements I will adjust the lifting angle to 42 degrees.

Another suggestion made was to demagnetize. I didn't do that since I didn't notice any evidence of magnetism. Combined with the "double-check-for-pivot-rust" suggestion but I can strip the watch again and do both; just to rule those options out.

Yes, a slight wear-ring in the bottom balance staff pivot has be noticed, but the lack of a staking set prevents me from changing the balance staff out. Whether the jewel-holes are worn out, I can't say; they look okay, but they may well be "oversized" (?). The oiling of the cap-jewels went fine, so I don't think it's a matter of too much oil.

Reading the comments so far, the plausible causes of all the problems could be the hair-spring and the balance; and indeed both do have known issues. Next to the rust/demagnetize stripping, I'll concentrate on these two first, within my (tool) limitations, and see if things can be improved.

I hope that I'll get this weekend time and will report the results in my thread: http://www.watchrepairtalk.com/topic/5884-landeron-48-restoration-project-attempt-2/

Thank you for your help so far

 

Edited February 23, 2017 by Endeavor

[JohnR725]

5 hours ago, Endeavor said:

Another suggestion made was to demagnetize. I didn't do that since I didn't notice any evidence of magnetism.

A interesting difference between a hobbyist and professionals. Hobbyist are limited by their tools professionals Ideally should have everything but usually don't. So if you're around professional shops professional watchmakers especially those working on upper end watches then they are very obsessed with Demagnetizing. So removing the effect of magnetic is a good thing to do because it shows up in a variety of ways and it's an easy thing to deal with rather than pondering all sorts of other problems that may or may not be there.

 

[Endeavor]

@JohnR725 I made myself a demagnetizer and will perform another W.O.S.-measurement after I demagnetized all the parts. A staking set is missing and unfortunately there are no professional watchmakers shops anywhere close ..... We'll see and comes time, comes a solution

 

Edited February 23, 2017 by Endeavor

[Delgetti]

I just checked my watch with the Landeron 248 and it shows an amplitude of about 280° dial up and dial down and the last service was over 10 years ago. So a high amplitude should be possible even with these old movements.

[digginstony]

A interesting difference between a hobbyist and professionals. Hobbyist are limited by their tools professionals Ideally should have everything but usually don't. So if you're around professional shops professional watchmakers especially those working on upper end watches then they are very obsessed with Demagnetizing. So removing the effect of magnetic is a good thing to do because it shows up in a variety of ways and it's an easy thing to deal with rather than pondering all sorts of other problems that may or may not be there.
 

I'm only a hobbyist so please ignore any ignorance shown but in other threads when magnetism is referred too its always in the context of the watch running fast. I assume this is the hairspring becoming magnetised and the coils sticking together. Are there other parts of the watch that can be effected and what are the sort of symptoms displayed ?

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[JohnR725]

3 hours ago, digginstony said:

I'm only a hobbyist so please ignore any ignorance shown but in other threads when magnetism is referred too its always in the context of the watch running fast. I assume this is the hairspring becoming magnetised and the coils sticking together. Are there other parts of the watch that can be effected and what are the sort of symptoms displayed ?

Many times we tend to make absolutes in watch repair when it's not an absolute. So the effect of a magnetic field will vary modern watches supposedly are not affected. Yet I know of some professional shops where they are obsessively concerned about magnetic fields and Watchmakers are continuously demagnetizing their watches perhaps to the point of lunacy. Although the particular shop in question one of the watchmakers did a demonstration of the effect of putting a magnetic next to one of the so-called watch that can't be magnetized and there is a reason why they do what they do.

So on older watches with steel hairspring if enough magnetic field is applied the hairspring coils conceivably could stick together shortening the hairspring and running abnormally fast.

Images attached section of a timing machine manual explaining what a magnetic field could do to a watch. Then timing machine image the one with the sine wave was before the watch was demagnetized hen the other one is afterwords. This was a small 12 size approximately Howard pocket watch in desperate need of servicing which is why the amplitude is insanely low and the beat looks bad.

[Endeavor]

@JohnR725 Very interesting information ! This timing machine manual you are referring to, is that somewhere to download? Or, and now I'm pushing my luck,  are you perhaps able to scan it and combine it in a PDF?

My Watch-O-Scope is a self-build machine ....... so no manual ......

[Endeavor]

@Delgetti I'm sure old movements can run as good as, or nearly as good as when new; if maintained very well. Yours has had a service 10 years ago. Mine has a unknown history and judging the condition in which I obtained the movement (none-runner), I think it hasn't seen a service for decades and perhaps never had one during its working life? I therefor think that one can't compare the same movements just 1:1. Nonetheless, 280 is a nice figure to aim for. Thank you for letting me know ........ and since yours runs so well, can we do a one-for-one swap?  

Edited February 24, 2017 by Endeavor

[JohnR725]

As I have a timing machine obsession I've accumulated quite a few manuals. So attached is interpretations of the timing machine display. Fortunately whether it's paper electronic etc. interpreting the display is basically the same. There are though some examples where paper tape is nice because you can run along print out like in the PDF number 14. On the other hand with modern timing machines some of them and some of the software you can run a time plot and do the same thing better.

Then you have to be careful when interpreting the waveform does as it can almost become like crystal ball reading subject to interpretation. Conveniently are not finding a manual lurking around here which has all sorts of bizarre display's that all start to look the same but have different descriptions of what the problem may or may not be. So the timing machine will point you in a direction but you still have to use good watchmaking skills To figure out what the problem is.

Timing-Machine-Charts.PDF

[Endeavor]

@JohnR725 Thank you very much !! It's a whole lot more then I had an hour ago

I'm sure in only a few occasions problems are clear cut, so it needs skill, understanding and experience. For me this manual is a very good starter!

Thanks again !

[digginstony]

Many thanks JohnR725 for your time and trouble replying to my question and information provided [emoji4]

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[Watchtime]

@JohnR725Thanks for sharing this, really a big step towards interpretation the readings of a timingmachine.

 

[frenchie]

@JohnR725 Thank you!!! What a trove of information!!!