I wonder how accurate this is. I had assumed making a balance spring precise enough to be reasonably reliable was extremely difficult. Being made of a plastic l

I wonder how accurate this is. I had assumed making a balance spring precise enough to be reasonably reliable was extremely difficult. Being made of a plastic like substance that can only be accurate down to a visibly low resolution, I would guess it's not very accurate. Sort of a moot point considering the main spring only lasts 30 minutes.