po back from service with a slow rotor ?

[FredZ]

About a month ago I got my PO Skyfall 8507 back from service . Its doing well but i have noticed that it may not be getting fully wound after a day or two on the wrist. I must admit that Im not a Olympic gymnast .On the other hand I have not had that issue with any of my other 8 series calibers in a number of watches.So I have a theory that it may be the rotor is lazy or stiff or something. Any credibility in thinking it needs a break in period.

 

[Canuck]

The rotor should appear more enthusiastic the closer to run down the watch is. The reverse being true when the watch is fully wound.
Try testing the rotor action after the watch has been idle for about 36 hours. Then wind it manually about 50 turns on the winding crown (you won’t hurt the watch), then test the rotor action again. Get back to us with your findings.

 

[FredZ]

I appreciate your suggestions. I will be trying the process you suggest. I will share the results. May I ask how the rotor measures the status of the winding?

 

[Canuck]

F FredZ

I appreciate your suggestions. I will be trying the process you suggest. I will share the results. May I ask how the rotor measures the status of the winding?[/QUOTE

With the mainspring run down (or nearly) it is close to a “relaxed” state. As winding commences and the spring begins the process of becoming wound, it gradually increases its resistance to the winding process. The more it is taken away from its relaxed state, the harder it tries to get back to that relaxed state. The rotor is having to work harder, the closer to the fully wound state that the mainspring approaches. The effect on the freedom of the rotor to rotate freely is evident as the mainspring becomes for fully wound. When the mainspring finally arrives at its fully wound state and the bridle begins to slip inside the mainspring barrel (completely normal. That is the way automatics operate), the rotor is working its hardest, and its freedom to rotate freely is most impaired.

The further any metal is distorted from its relaxed state, the harder it fights to try to return to the relaxed state.

 

[FredZ]

Thank you so very much for your explanation. I understand now . Much appreciated. I will report the results of the test.

 

[FredZ]

Ok well I tried to follow your advice and basically haven’t come to a conclusion with any certainty. As per your instructions I wound the watch 55 turns . The speed of the rotor didn’t seem to change one way or the other. I put it on the timegrapher and have sent along the results. If nothing changes I’m going to just wear it and enjoy it. Again thank you for your insights

 

[Canuck]

I have repeated my instructions, here:

The rotor should appear more enthusiastic the closer to run down the watch is. The reverse being true when the watch is fully wound.
Try testing the rotor action after the watch has been idle for about 36 hours. Then wind it manually about 50 turns on the winding crown (you won’t hurt the watch), then test the rotor action again. Get back to us with your findings.

Please note, I said test the rotor action after the watch has been idle for about 36 hours! You should observe the action of the rotor at this point, with the mainspring nearly run down! You’ll likely find the easier rotation of the rotor at this point. THEN wind it manually about 50 turns on the crown. THEN, observe the (probable) slower rotation of the rotor.

You’ll likely see a difference in the freedom of motion of the rotor between fully run down, and fully wound up.

Step 1/ Run 36 hours.
Step 2/ Observe rotor function.
Step 3/ Wind 50 turns manually.
Step 4/ Observe rotor function.

For the results to be meaningful, you must observe the above sequence.

 

[FredZ]

I followed your instructions . The results were that after 36 hours of layup the rotor moved in a relaxed way. It seemed to move faster than I previously observed. I then wound exactly 50 turns and observed the rotor action decrease significantly. The rotor was observed at the same rate which gave rise to this question. In summary your explanation is right on point. Thank you so much.

 

[Canuck]

F FredZ

I followed your instructions . The results were that after 36 hours of layup the rotor moved in a relaxed way. It seemed to move faster than I previously observed. I then wound exactly 50 turns and observed the rotor action decrease significantly. The rotor was observed at the same rate which gave rise to this question. In summary your explanation is right on point. Thank you so much.

Glad to help. Enjoy your watch.