po back from service with a slow rotor ?

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.

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.