hello everyone. my question is if your watch is running slow do you adjust towards the "S" or towards the "F" ? (maybe explain what the thing does). thanks

Hi Joe

If you notice the end of the regulator there should be two pins that point down towards the hairspring & the last coil of the hairspring should rest between the two pins. By moving the regulator one way or the other the movement of the pins causes the active length of the hairspring to either lengthen or shorten thereby causing the balance to vibrate faster or slower.

If the regulator is moved towards the F marking the watch should run faster, the opposite if moved towards the S.

You must keep in mind this only makes a small change in the timing.

At least that is my understanding, perhaps someone else has a better description.

Tom

thanks Tom. that's more than I knew before.