Nifty idea for helping adjust hairsprings

[ic0n]

OK, you probably all know this wrinkle, but it was new to me. I've been trying to adjust the last coil on a Breguet overcoil so that all the various bits lined up. I was doing this on the upturned balance cock (with the spring removed from the balance of course). I saw a video where the watchmaker took an impression of the bottom of the balance cock on a thin sheet of rodico, which captured the location of the curb pins, the stud mount position and the jewel hole. This is carefully removed from the cock, and the holes transferred to a piece of paper with a pin poked through the rodico. I repeated this 3 times to get a sense of 'repeatability'. I then drew the curb pin circle from the centre with a pair of compasses. You can then drop the hairspring on the diagram and see where everything needs to be, and tweak accordingly. Much easier!