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 first setting, you remove the roller from the balance as shown in the photo above.
In the second setting, the balance wheel spokes are firmly held down by a stake, and then a punch knocks out the staff.
Once you have done this, you will never go back to the lathe, as it’s easy, safe, and the chances of damaging the balance are far lower.
Click on the photo to enlarge it. No damage whatsoever to the balance, and a clean cut edge on the old staff. Worth the £400 for the tool if you replace staffs.
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.
The old Pearl will go into retirement, but I will keep it if I ever have to do something that might damage a stake.
Now I use the centre punch to make sure the hole is centred.
Now I find a flat and a rounded stake that just fit over the staff.
I start off with the flat stake, to make sure the balance sits level on the new 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.
After a bit of riveting, the staff finally starts gripping, and is now firmly riveted to the balance.
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.
The roller is back on.
Last but not least, I put the hairspring back on, and the job is done. The balance goes back to Sweden.
Hi. I am tempting to replace a balance wheel stake on a 1930’s omega packet watch.
How do I find the correct replacement stake? As mine has broken (wheel was loose in the movement) I have no idea how to find the correct replacement stake. I if I can find the correct stake I think I can fix it. Everything else looks in great shape.
Please practice on a cheap watch first. If you have never done this before, it probably won’t end well.
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Hi Christian, that’s a lovely little tool and a great demonstration, thanks!
Would you need to poise after a operation like this?
Yes, I do put the balance over the poising tool afterwards to check.
This is a fantastic post, Christian. Really enjoy learning more of the art and appreciate your time in producing such a resource! I know they take a bit longer, but any time you get the itch to write a tools and techniques post, know that you’ve got an eager and appreciative audience.
I’m curious, when attaching the roller, how do you reposition it in the same location relative to the balance? In other words, do you mark the balance first? BTW, I appreciate your site and work. Quite impressive.
Hi Dan,
The roller always sits with the impulse pin at 90 degrees to the spokes. I take a photo so I know which side it sits on. You can also deduct the position from the mark for the hairspring stud on the other side.
Hi Christian this is my first reply on your blog, but have been reading since you started.I am a amateur watch maker and always learning something new, love the site keep up the good work. This is the best photos i have found of the before and after of the platax tools work, very surprised at the lack of damage to the balance wheel. I think i will now try and source a used one as they are expensive new. PS love the new workshop good luck for the future.
I was looking for a used one for ages… The ones that come up for sale go for a lot of money, or are in terrible shape.
Very interesting, that seems a large investment in tools for what the ignorant (me) might assume was a fairly straightforward job. I’d have just thought the staff was pressed in by hand – is a lot of pressure required? and accuracy obviously paramount?
You can put the staff in by hand, but it then needs to be riveted into position. You can only remove an old staff with a graver on the lathe, or with the Platax tool.
Thanks, very interesting to see how it’s done. I’d love to see more like this, I find it fascinating!
Looks like an arcane art best left to the initiated…