Strange timegrapher graph

[beastomaniac]

What kind of issue this timegrapher graph attached represents? The line goes fine and suddenly it drops significantly. This sympton occures at least in dial down position, is it possible that the second hand touches the minute hand for example?

[matabog]

Usually, when coils touch each other or there is banking, the rate increases. 

In your case the rate decreases. I think there is a problem with the regulator pins - the hairspring is not centered between them, or even rests on one of the regulator pins - and when the amplitude marginally increases, the equivalent HS length increases, because it will not touch the regulator pin.

 

Also try a demagnetization.

Edited December 8, 2016 by matabog

[jguitron]

Can you do a longer term capture? I'm only starting to dig into the timegraph troubleshooting but my initial thought is that it could be a defect in one of the train wheels? Then I guess it would happen on all positions.... hmmm... maybe debris that affects only on that position? Interesting! I hope you get to the bottom if it. Good luck!

Cheers!

 

[rodabod]

How does the amplitude vary when the rate suddenly changes?

[beastomaniac]

51 minutes ago, rodabod said:

How does the amplitude vary when the rate suddenly changes?

Good point, which I forgot to mention - the amplitude doesn't react into these drops in any way. Amplitude goes dial down around 274-278 degrees when fully wound, even if the beat drops.

[matabog]

I reiterate: check that the HS is moving from one regulator pin to the other in one balance oscilation. and with somekind of symmetry

Edited December 8, 2016 by matabog

[beastomaniac]

I reiterate: check that the HS is moving from one regulator pin to the other in one balance oscilation. and with somekind of symmetry

Sorry, I didn't totally get this. How do I check this?

[matabog]

http://raulhorology.com/2012/12/the-mark-of-a-true-watchmaker-forming-hairsprings-part-4-pinning-to-the-stud-final-adjustments/

[beastomaniac]

http://raulhorology.com/2012/12/the-mark-of-a-true-watchmaker-forming-hairsprings-part-4-pinning-to-the-stud-final-adjustments/

Oh my, I'm not ready to manipulate hairspring yet =)

[matabog]

Then don't touch the HS. But you could confirm by putting a 7x magnifier and checking the HS between the regulator pins.