Thinning spring & coiling

[Nucejoe]

 

[LittleWatchShop]

This guy is impressive.

Recently (and I posted about it), I was faced with a 400-day suspension spring that was too thick.  The clock ran fast.  Rather than order another of the correct size, I used sandpaper folded over the spring.  I ran the folded sandpaper up and down repeatedly.  This worked wonderfully well to calibrate the rate of the clock.

But, the work in this video is many pay-grades above my little effort!