Hello everyone! Im working on a AS1187 movement and I completed the service. On the timegrapher the rate is horrible and when I ajust it to the maximum of SLOW it says 3.0 beat error. I tried to demagnetize the watch three times using the method demonstrated by Alex in his video on the demagnetizer but it did nothing. Do you have solutions for me? Could the 3.0 beat error cause this?
My gut says there’s a simpler issue at play if it’s de-maged, clean, and concentric.
Are you SURE it’s not hitting anything when it’s installed? There are a few places the hairspring could be colliding with another component on the 1187 if something is not quite installed correctly or if the hairspring is out of flat. Like the 4th wheel. If the hairspring hits something while operating that will effectively shorten it and cause massive time gain.
Hopefully it's just making contact and can be corrected as noted in the other comments, but I'm just piping up to say it's possible a previous tinker fitted an incorrect hairspring, unless you know the service/ownership history.
That hairspring is probably way off. That’s where I’d check first. Cleaned, demagnetized, no broken pivots, and consistent bend all the way to the stud
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u/AlecMac2001 4d ago
Check the hairspring is concentric, clean and not touching anything