Quest for the missing amplitude

[ezy123]

Greetings all. I've got an old 565 movement that's a bit on the low side. Fully wound it sits at about 230ish on the timegrapher. The plots are fairly linear in all posns, and it keeps good time. It started as a non runner, so I'm pleased it's going. However I'd like to think I can get it running a bit better. 

Thus far....

New mainspring, movement stripped and serviced. Balance hairsping removed and manipulated slightly for concentricity. Jewels pegged. 

Train Bridge observed free spinning with pallet fork removed. Even with a very light turn of the crown. 

Pallet fork and escape wheel all straight and in good order. 

Balance has very little observable end shake. Moves freely on its pivots with the lightest agitation. 

 

If anyone with experience of these movements could give me some pointers of where I might look next, I'd really appreciate it. I am still very much at the learning stage but enjoying the process! 

 

Best 

 

David 

[Klassiker]

What is the amplitude like in the other positions, and what is it after 24 hours?

By the way, you mean Omega 565? How long have you let it run in?

Edited August 24, 2020 by Klassiker

[Nucejoe]

I check pallet jewels for wear under high magnification.

 

 

 

 

[HSL]

To get a better feeling of what is showing up on the time graph one have to have a basic knowledge of the functions of the watch, for example on the display one usually look at the amplitude and the beat error since this is quite easy information to digest.
But when fault finding there might appear noise and disturbances which plots periodically on the display. To narrow in where the error is one can look at in which frequency the phenomena appears.
If one are lucky enough one can read the peaks of the noise and through that see it appears for example every 5:th second or faster, that will give you a hint that the problem is either in the escapement or in the balance area.
If the noise appears slightly slower let’s say about one in a minute or slightly less then the error might be around the fourth (seconds) wheel.
So the longer time it takes for the error to appear the further back in the train the fault is.

This is why they in the manuals can say approximately where you should look for the fault in your watch.
But first you have to know approximately the ratio of your drivetrain, here is an example of one for the ETA 2824-2.

So just from looking at that graph one really can’t say what it might be, but when one knows if it appears periodically one could start pinpoint the trouble area.
Like here one see a sudden movement typical for a dirty mainspring, but since we don’t know how frequent it is one just can guess.

[wudce]

4 hours ago, Nucejoe said:

I check pallet jewels for wear under high magnification.

 

 

 

 

That's what I found to be the problem on a watch I had been working on. I can see the hole is out of round some. After I replace the jewel the amplitude came up from a low of 220 to 278 so I was happy.

[Nucejoe]

16 minutes ago, wudce said:

That's what I found to be the problem on a watch I had been working on. I can see the hole is out of round some. After I replace the jewel the amplitude came up from a low of 220 to 278 so I was happy.

Right , Faulty jewels to the fork arbour causes some energy loss, which you dealt with.

However, lots of energy is lost due to friction that scratched face of pallet stones create. 

[Nucejoe]

2 hours ago, HSL said:

To get a better feeling of what is showing up on the time graph one have to have a basic knowledge of the functions of the watch, for example on the display one usually look at the amplitude and the beat error since this is quite easy information to digest.
But when fault finding there might appear noise and disturbances which plots periodically on the display. To narrow in where the error is one can look at in which frequency the phenomena appears.
If one are lucky enough one can read the peaks of the noise and through that see it appears for example every 5:th second or faster, that will give you a hint that the problem is either in the escapement or in the balance area.
If the noise appears slightly slower let’s say about one in a minute or slightly less then the error might be around the fourth (seconds) wheel.
So the longer time it takes for the error to appear the further back in the train the fault is.

This is why they in the manuals can say approximately where you should look for the fault in your watch.
But first you have to know approximately the ratio of your drivetrain, here is an example of one for the ETA 2824-2.

So just from looking at that graph one really can’t say what it might be, but when one knows if it appears periodically one could start pinpoint the trouble area.
Like here one see a sudden movement typical for a dirty mainspring, but since we don’t know how frequent it is one just can guess.

OP, reports fairly linear plots.

Educational to me if you show where you got the notion of periodic amplitude fluctuation, are you speaking of a general possibility?  or do you see any indication on timegrapher display?  TIA

[HSL]

1 hour ago, Nucejoe said:

OP, reports fairly linear plots.

Educational to me if you show where you got the notion of periodic amplitude fluctuation, are you speaking of a general possibility?  or do you see any indication on timegrapher display?  TIA

Well if you look at the beginning of the graph which is posted you see there is a quite a dip in the beginning, that is not normal.

Since it is a microphone-based system what you see is a graph recorded from the noise coming from the movement which is then filtered through an array of low pass and high pass filters and the result is then run through a signal processing system to find the resulting peaks. The amplitude will be a result of the median of these peaks. 

A faulty escapement would give some small ticks with a period of about 5 seconds, but a fault in the mainspring like when it is stuck to gue in the barrel will generate a random dip when it gets loose, just as you see in the posted graph.

In general, I would think by now the cleaning and lubricating of the pallet jewels and the impulse pin will give you a boost in amplitude and usually one can’t see a uniform oxidation on the impulse faces on a time graph. To gain a 10-15 degrees more one could lubricate the jewels too with for example Moebius 9415.
But a worn escapement, pallet jewel for sure will give some new noise to the pattern.

So my point here is to not jump into conclusions to fast when a random graph is posted but instead take a systematically and methodically approach .

I forgott to paste the Witschi graphs as an example of some common curves.

There will of course be varieties of the graphs but I guess they wanted to give some examples.
Here you see how the train can act erratically over a long time picture 6 on the left one have to keep in mind the waves are elongated over longer times the futher back in the drivetrain it appears, compared to a untrue escape wheel (worn pivot) which will generate a wavy  pattern with higher frequency.But in both examples the ampltude will get lower since you get presented with either the effective value or median value of the amplitude depending of which filtter the manufacturer decides to use.

Well guess tht was all from me today 

 

 

Edited August 24, 2020 by HSL

[JohnR725]

23 hours ago, ezy123 said:

Greetings all. I've got an old 565 movement that's a bit on the low side. Fully wound it sits at about 230ish on the timegrapher. The plots are fairly linear in all posns, and it keeps good time. It started as a non runner, so I'm pleased it's going. However I'd like to think I can get it running a bit better

 

20 hours ago, Klassiker said:

What is the amplitude like in the other positions, and what is it after 24 hours?

By the way, you mean Omega 565? How long have you let it run in?

I don't know if you noticed but we've had some recent people sharing the servicing of their Omega watch.The first link below is the 565 and the amplitude is around 240° just about what you have. The second link seems to missing the timing machine results but you might find the servicing notes helpful. Then Omega considers the 552 and 565 in the same family.

Also I find it interesting that the watch keeps good time but you're unhappy with the amplitude?

Then the second quote more or less what I would ask and I would be curious about the amplitude at 24 hours and of course timing in multiple positions.

When timing a watch it's always important to establish a timing procedure. At least this is what watch companies suggest you should do. So for instance Omega's recommendation is when you wind the watch up you wait somewhere between 30 and 90 minutes. I find personally around 30 minutes is good. Then 24 hours later is considered 23 1/2 hours all the way to 25 hours. Also when changing positions on the timing machine they suggest a stabilization time of 20 seconds. Then 40 seconds per position for how long they measure.

Now that we have a timing procedure it be nice if you would time the watch and get back to us with results. Even though the watch companies specify the number of positions for various watches for diagnostic purposes it's really nice to time in six positions. Dial-up and dial down and using the crown is a reference or whatever you like as a reference four separate positions. Like crown up right left and down six positions. Then writing down the rates in those positions and the amplitude beat is of lesser importance. Then you give us the numbers and it be really nice 24 hours later you do the test again.

I find watch companies interesting versus discussion groups. In the discussion group like this the most important thing of all is amplitude followed by timekeeping. Strangely enough the watch companies are more concerned about timekeeping and typically only worry about minimum amplitude at 24 hours. Then until the original poster comes back with some real numbers it's pointless to jump to conclusions whether the watch has a problem because we don't have enough numbers to compared to what Omega has for timing specifications.

https://www.watchrepairtalk.com/topic/15628-first-project-omega-genève-cal-565/

https://www.watchrepairtalk.com/topic/15848-omega-552-servicing-notes/

 

[jdm]

16 hours ago, wudce said:

That's what I found to be the problem on a watch I had been working on. I can see the hole is out of round some. After I replace the jewel the amplitude came up from a low of 220 to 278 so I was happy.

Well spotted, this is an interesting note. In the long term either the escape wheel or the impulse jewel push the pivot by one side enough to bring the hole jewel out of round. Maybe if the pallet pivot had been oiled that wouldn't have happened, at the initial cost of some amplitude.

[Watchtime]

Hello ezy123,....welcome to the forum, maybe you could post your introduction? As you can see, there is some great info about the amplitude and possible problems.

[rodabod]

Given that this is specifically an Omega 500-series, let me repeat some observations of my own:

- These have very fine pivots and are susceptible to sticky bearings. It must be scrupulously clean - especially the balance jewels. Sometimes they take a day to “run in” which is possibly the result of old lubricant dissolving into new and making the bearing surfaces more slippery. 
 

- The centre wheel can be susceptible to wear which causes increased side-shake and poor meshing of the barrel teeth. 
 

- As an automatic, the barrel wall can wear, or the mainspring bridle can provide less friction than need be. Check the number of turns before slippage occurs. 

[ezy123]

3 hours ago, Watchtime said:

Hello ezy123,....welcome to the forum, maybe you could post your introduction? As you can see, there is some great info about the amplitude and possible problems.

Hi there. I've already said hello a while ago I think? 

[JohnR725]

39 minutes ago, ezy123 said:

Hi there. I've already said hello a while ago I think? 

It appears your correct you did do an intro. It also appears that you like to work on Omega watches only which is fine but availability of spare parts especially when you're starting off in watch repair will make this a very expensive hobby. It be better if you start practicing with something disposable.

https://www.watchrepairtalk.com/topic/15273-hello-from-london/?tab=comments#comment-136038

 

 

 

[ezy123]

1 hour ago, JohnR725 said:

It appears your correct you did do an intro. It also appears that you like to work on Omega watches only which is fine but availability of spare parts especially when you're starting off in watch repair will make this a very expensive hobby. It be better if you start practicing with something disposable.

https://www.watchrepairtalk.com/topic/15273-hello-from-london/?tab=comments#comment-136038

 

 

 

Thanks John 

I agree with you it has been expensive. I've since diverged off to a seiko 7005a which went well and is now back together running nicely. 

 

I return to this omega every now and again to see if I can get to the root cause 

 

[ezy123]

3 hours ago, rodabod said:

Given that this is specifically an Omega 500-series, let me repeat some observations of my own:

- These have very fine pivots and are susceptible to sticky bearings. It must be scrupulously clean - especially the balance jewels. Sometimes they take a day to “run in” which is possibly the result of old lubricant dissolving into new and making the bearing surfaces more slippery. 
 

- The centre wheel can be susceptible to wear which causes increased side-shake and poor meshing of the barrel teeth. 
 

- As an automatic, the barrel wall can wear, or the mainspring bridle can provide less friction than need be. Check the number of turns before slippage occurs. 

Stripped the moment down and again and followed your very useful advice. 

Upon rebuilding the gear train, I've found that the centre wheel has a lot of side shake/slop, which is causing the gear run out of true with barrel and 3rd wheel! 

I'm sure this would create a fair bit of drag in the train. So I'm gonna buy a new centre wheel and new upper/lower jewels. 

Fingers crossed this will be the answer. 

Thanks to all those who have offered advice thus far 

[rodabod]

Hi, I think you’ll find that the jewels are absolutely fine. The way to tell is that they will be oval-shaped if they are worn as the side-thrust causes friction only on a single side of the bearing. 
 

I was surprised to see that the centre wheels on these wear so much, but there are a lot of variables at work here: the depth of the bearing edge (shallower on thin watches = increased pressure) and continuous high level of torque if the watch has been worn by someone fairly active. The wear at the shoulder of the arbor is easily measurable with vernier calipers, so let me know if you want to know how a working one measures. 

[rodabod]

On 8/25/2020 at 3:21 PM, rodabod said:

- The centre wheel can be susceptible to wear which causes increased side-shake and poor meshing of the barrel teeth. 
 

To give a better illustration of what excessive centre wheel side-shake looks like, here’s a Cal 501 (the earlier auto before what I should really refer to as the 550+series). 
 

 

[ezy123]

On 9/12/2020 at 3:53 PM, rodabod said:

To give a better illustration of what excessive centre wheel side-shake looks like, here’s a Cal 501 (the earlier auto before what I should really refer to as the 550+series). 
 

 

IMG_9257.MOV FullSizeRender.mov

Thanks for the video. That's similar to the sideshake I'm getting. 

I fitted a new centre wheel, and while the sideshake has reduced somewhat, it's still fairly significant. 

 

So I've managed to get my hands on a favorit jewelling tool off ebay. Gonna have a go at changing the upper and lower jewels, and then I will report back. 

 

Thanks for the continued help and input. 

 

David 

[rodabod]

Hi David,

I’ve just fitted a new centre wheel on that movement above. At first I only gained around 20 degrees amplitude, but this climbed to 40 more degrees after several hours of run-in. I noticed that the NOS wheel had a satin finish and was not polished. I reckon this will have effectively polished itself while running. 
 

It’s worth using a micrometer to compare the original bearing surface diameter to the new wheel. Both bearing surfaces were around 5/1000mm narrower on my old wheel, but this does not take into account narrow grooves on the surface as the micrometer jaws are wide. This tiny difference in diameter causes a lot of side shake. 
 

 

[rodabod]

One other tip: if you suspect excessive side shake then you can actually push the centre wheel pivot sideways (in the opposite direction to the barrel thrust) while the watch is running to see of the amplitude increases or not.