I have a cool old Seiko 7S26 based watch which has served me faithfully for several years and I'm sure has several more left in it. I really like automatic watches since there is no battery and the second hand sweeps across the dial, just seems cooler than the ticky tock of a quartz movement (but quartz on the other hand is pretty bullet proof). But enough about that, my watch has been stopping intermittently, and sometimes if I listened close after "winding" the spring (which can only be done by rocking the watch back and forth to turn the pendulum), there was a sound like a spring unwinding. Initially I thought the "magic lever" was worn down - described in more detail here - that link is full of info on the 7S26 movement. But when I opened it up to check the ratchet mechanism it seemed OK. So I sealed it back up and it seemed to be working magically again - for a less than a day, then it stopped again. The next time it stopped however, I could hear the pendulum scrapping on the inside of the case back. I figured that it must be the pendulum itself had worked loose so I took it apart once more, and yep, the screw which secures the pendulum had worked loose (not completely), so I just tightened it down - and so far so good. I took a pic and put an arrow pointing at the screw which was loose, I just tightened it down snug and it seems good now. Hopefully it will be a pretty quick fix for a watch that was intermittently stopping. I will probably need to check on what type of oil to use in the ball bearings for the pendulum in case it was too much friction which caused it to work loose. I get the feeling this movement is going to need an overhaul soon, but I have never done that before and it is probably cheaper to replace it than service it.
Welcome to my Stoopid corner of teh Internet. It's mostly gonna be 3D printing stuff, but I also post some recipes, projects, and the occasional rant here as well. More Stoopid stuff is updated regularly.