Beat Error advise please

[Birdie]

I’m looking for some guidance please.

I have recently adjusted my Eberhard watch which has a Valjoux 7758 calibre.

The watch was running slow at about a 90SPD. When I put it on the time grapher It was clearly showing slow and also the gap between the two beat error lines was about 6mm (on the screen) and the beat error was reading 2.4. So I decided to adjust the stud as well as the regulator. As I moved the stud the lines became closer but the beat error started to rise. I managed to get the two lines almost on top of each other but the beat error reading was showing 5.8ms. I also regulated the watch and achieved minus 1SPD. I left it at that and have worn the watch now for over two days and the accuracy is good at only losing 4 seconds in that time which I’m happy with. The question I have please, is, can anyone explain why the two lines on the time grapher would get closer but the beat error reading would increase.

Hope someone out there can advise me. I have also uploaded photo of the time grapher screen.

[HectorLooi]

I've not seen this before but my mentor did warn me about this. When the beat error is so big until the display "rolls over" the line, it can sometimes display as a single line.

Try adjusting the stud again to get a small beat error reading.

[Birdie]

Thanks for response HectorLooi. I did try adjusting the stud the other way to reduce beat error but the line drifted apart and also I could not get the SPD better than about minus 10

[clockboy]

8 hours ago, Birdie said:

I’m looking for some guidance please.

I have recently adjusted my Eberhard watch which has a Valjoux 7758 calibre.

The watch was running slow at about a 90SPD. When I put it on the time grapher It was clearly showing slow and also the gap between the two beat error lines was about 6mm (on the screen) and the beat error was reading 2.4. So I decided to adjust the stud as well as the regulator. As I moved the stud the lines became closer but the beat error started to rise. I managed to get the two lines almost on top of each other but the beat error reading was showing 5.8ms. I also regulated the watch and achieved minus 1SPD. I left it at that and have worn the watch now for over two days and the accuracy is good at only losing 4 seconds in that time which I’m happy with. The question I have please, is, can anyone explain why the two lines on the time grapher would get closer but the beat error reading would increase.

Hope someone out there can advise me. I have also uploaded photo of the time grapher screen.

I have never seen that before. I would run for a while to see if it settles but I would not be surprised is the timegrapher is the fault.There is an app you can get for your smartphone “watch Tuner” and use it to cross check.

[jdm]

2 hours ago, Birdie said:

I did try adjusting the stud the other way to reduce beat error but the line drifted apart and also I could not get the SPD better than about minus 10

That is because the lines are rolled over as explained before. Correct the BE by looking at the numbers, not the lines. Eventually, even with a perfectly acceptable .5ms error, lines will be very close.

Quote

I would not be surprised is the timegrapher is the fault.

Not at all. The rolling of lines has been discussed before

Quote

There is an app you can get for your smartphone “watch Tuner” and use it to cross check.

I wish it was so easy. Phone or desktop apps can't measure accurately as an instrument using a purposely made, amplified microphone.

[Birdie]

19 minutes ago, jdm said:

That because the lines are rolled over as explained before. Correct  BE looking at the numbers, not the lines. Eventually even with a perfectly acceptable .5ms error they will be very close.

Not at all. The rolling of lines has been discussed before

I wish it was so easy. App and desktop phone can't measure accurately as an instrument with a purposely made, amplified microphone.

Thanks all very much for your advice. I will try to get the reading as close as I can to zero and see if I can regulate to the same accuracy.

[mikepilk]

Is the movement in the case on the timegrapher?  If so, remove it, you get a cleaner signal.

I have had this before. Remove power from the mainspring, and sight along the pallet (if possible) to see where it is sitting in relation to the impulse jewel and banking pins. With 5.7ms beat error the impulse jewel will be a long way (20-30deg?) from the centreline. Adjust it until it looks fairly central, then put it on the timegrapher  

[clockboy]

Perhaps it’s just an error that can happen with the Timegrapher 1000 I have never had this with the Timegrapher 1900. 

[Birdie]

Thanks all very much for your help

[Klassiker]

19 hours ago, clockboy said:

Perhaps it’s just an error that can happen with the Timegrapher 1000

If you mean roll-over, it happens with the 1900 too.

[JohnR725]

as mentioned above we've discussed this before. Then last time I asked the same question I'm going to ask again because it looks like I never got answer last? Would anyone with the Chinese 1900 deliberately adjust the beat error as far as you can and see at what point the graphical display is no longer indicating that. With the much larger graphical display it should be obviously a much bigger number and it may actually not roll over at all there may be enough pixels.

it's why you always have to pay attention to the graphical display has to agree with the numbers and then the watch has to agree with the timing machine. You could also let the power off and physically put the watch in beat or get it reasonably close then see what it is on the machine.

 

 

[Klassiker]

OK, will do. Answer for you shortly.

[clockboy]

5 hours ago, Klassiker said:

If you mean roll-over, it happens with the 1900 too.

I have been lucky then. I have owned the 1900 for approx 8 years and regulated , lots of watches, very badly worn movements that were a mile out of beat, pocket, pin lever and high end watches and never encountered the cross over. Perhaps the software was different in the original units.

[jdm]

17 minutes ago, clockboy said:

Perhaps the software was different in the original units.

As John noted, it's the display that makes the difference. More pixels means more space, so lines don't roll over on the 1900 as it happens on the 1000, or not that easily at leaat. 

For a more complete comparison between models check our pinned topic:

 

[Klassiker]

OK, here are the results, and I stand corrected @clockboy, the Weishi 1900 will not roll over, or certainly not at less than the limit reading of 9.9ms. Here are some pics.

 

 

This is the starting point, with very low BE and lines on top of one-another. (Poljot 3133 chronograph)

 

Stud moved clockwise. Clear separation of the traces, blue on top. The separation is around 6mm.

 

Approaching the limit reading here, with BE=9.6ms. The separation of the traces is around 17mm.

 

This is the same adjustment as in the previous picture, but the yellow trace has "rolled over", but the blue one not yet. The traces are separated by 25mm. (25+17=42, which is the vertical height of the display field).

 

Here I have set the beat-error way over 9.9ms (estimate >11.5ms by scaling), but the displayed value is on its upper limit, and the traces are about 21mm apart (50% of the display field). If this is your starting point, you just have to guess which way to move the stud. The balance is so far out of beat that I suspect it is intermittently rebanking.

 

I will wait for the mainspring to wind down, then try to push the stud so far over that we can see real roll-over i.e. the traces converging, although the BE is increasing.

[jdm]

1 hour ago, Klassiker said:

If this is your starting point, you just have to guess which way to move the stud. 

I'm pretty sure one can tell by the color of the upper line. But I never cared to take a note of which one. 

[Birdie]

Thank you everyone for your input. It is very informative. I haven’t actually tried yet to adjust the beat error closer to the zero reading because the watch is running so accurate at the moment. It has now been five days and the watch has only lost 14 seconds to date. Can I ask another question then please.

If the watch is running so accurately (in my opinion) what is the benefit in trying to get the beat error back to zero on the time grapher. Will it damage anything if left as it is?

Thanks again all for your responses

[JohnR725]

1 hour ago, Birdie said:

If the watch is running so accurately (in my opinion) what is the benefit in trying to get the beat error back to zero on the time grapher. Will it damage anything if left as it is?

leaving the beat error  where it is will not hurt anything, but the watch will run better  to understand the beat error adjustments I have a link to a video..

https://youtu.be/B5aRlPhF9j0

 

[Klassiker]

On 7/24/2021 at 3:40 PM, Klassiker said:

I will wait for the mainspring to wind down, then try to push the stud so far over that we can see real roll-over i.e. the traces converging, although the BE is increasing.

I tried it, but there was no way to get real roll-over, with the traces converging as the balance is pushed further and further out of beat. With separation above 50% of the display field the traces started to lose linearity, then the balance stopped swinging all together. I never got the separation anywhere near 100% of the display field. The 1900 is roll-over proof!

[anilv]

Just nudge the stud one way and see it the beat error reduces.. if it increases then try the other way. You 'should' see increase/decrease in BE on alternate sides.

rgds

Anilv