I normally don’t do this (e.g. just replacing a balance staff without fitting it into the movement), but Thom asked nicely, so I took on the job. If he would have lived in the UK, I would have invited him to do it himself in my workshop, but Sweden is a bit far …
I used to turn the old balance staff out on the lathe, but I never liked the process, as it’s so easy to get the graver into the balance…
So finally, I invested a lot of money into a Bergeon Platax tool, which allows you to chase out the old staff without using the lathe. Great stuff!
In the second setting, the balance wheel spokes are firmly held down by a stake, and then a punch knocks out the staff.
Now it’s over to the staking set, and this is my brand-new Star. First use! To start off, I find the right hole for the balance staff.
Now I use the rounded stake to rivet the balance staff onto the balance. Slowly does it. I use light hammer strokes, and lots of checking. In between, I use the flat stake again to make sure everything is level.
And now you can see why I bought the Star staking set with the additional bottom bit. This allows you to use stakes as anvils, so I can rest the rivet of the balance staff on a stake, whilst pushing on the roller.
Last but not least, I put the hairspring back on, and the job is done. The balance goes back to Sweden.