I posted to the ClockSavant Instagram page a video summarizing some of the final stages of hairspring manipulation. You can see the video and summary here:
I also summarized the text of the post below:
I’ve posted a number of times about the need to regularly correct and manipulate hairsprings bent by past watch repairers, damaging or destroying your watch’s timekeeping and ability to run. I’ve discussed how difficult and time-consuming repairing hairsprings can be. There are many steps to correcting a hairspring and they are repeated over-and-over again in small increments to get the hairspring level and symmetrical in accordance with mathematical relationships that optimize accurate timekeeping in all watch positions. In this composite video with photographs, I show some of the steps taken after the hard work of manipulation is completed. The top left video shows the mainspring mounted to the balance cock without the balance attached. I am inspecting the hairspring for level, symmetry, and fit to the unique attributes of the balance cock. Though not shown, I will also assure that as I move the regulator that the hairspring remains equally between the balance cock regulator pins. If I find any defects I will retrace previous steps and manipulate the hairspring again. This is just one of many inspections performed after manipulation. In the top right picture I show the mounting of the hairspring to the balance to the precise height required for optimal results. In the bottom left I show beat error adjustment using the tool shown to achieve evenly distributed swing of the balance. In the final video I show the final corrected hairspring and balance performing in the watch.