Removing a balance staff. Should this video come with a disclaimer?

[VWatchie]

I'm pretty sure it was @nickelsilver expressing some disdain for all the adulation some watch repair channels get on YouTube. I think I've found such a rather egregious example, and for some reason, I'm starting to agree more and more.

So, why get expensive special tools to knock out a balance staff when you can just do it with your staking set?

 

 

[nickelsilver]

Well, it looks like it worked fine in the video! But it won't work that well every time. That's a Glucydur balance, which is almost as hard as hardened and tempered steel, so there was more resistance to deformation than a cheaper watch with a nickel or unhardened steel balance. It looks like the balance is quite true, and he didn't show any truing, so we would imagine that it staked on true. But he does show a poise error, and it looked like the balance was a rather loose fit on the replacement staff: this is an issue.

 

Knocking out a staff, whether unsupported like he's done, or with a Platax or one of the accessory clamps for staking tools, will enlarge the hole in the balance. Might be just a little bit (few microns), or a lot (few hundredths), but it will enlarge it. When riveting the new staff, in theory the rivet should deform equally and the staff will self-center in the hole, but in reality that's not usually the case. When I make a staff, which I do for 99.99% of staff replacements I do, I make the balance a snug fit, almost a press fit (it does require some pressure to seat, but isn't technically a "press fit"), on the new staff. So if I have a poise issue, it was there already... maybe because the staff was knocked out in the past, and a new staff was riveted in eccentrically, and the balance repoised to compensate? Who knows.

[VWatchie]

1 hour ago, nickelsilver said:

Knocking out a staff, whether unsupported like he's done, or with a Platax or one of the accessory clamps for staking tools, will enlarge the hole in the balance.

That's how I perceive it as well. However, perhaps worth mentioning is that when using a Platax tool (or similar) at least the stake will never enter into the balance staff hole. Personally, I would never punch out a balance staff as shown in the video no matter what alloy the balance was made of. The risk of permanently destroying the balance is imminent.

1 hour ago, nickelsilver said:

That's a Glucydur balance, which is almost as hard as hardened and tempered steel,

That's interesting. I didn't know that. Just wonderful to learn something new every day. Thanks!

I remember we were having a discussion about how these watch repair videos have flooded YouTube over the past few years and how people in general are in awe of them. I now see how these videos could mislead people to believe that they can fix their watches themselves and destroy them in the process. It makes me wonder if the people making these videos realise that. If I were to make such a video, like the one in the example, I would definitely have written or included a clear and large disclaimer for it, to make sure I have no responsibility for destroying family heirlooms. Hell, I even worry about that when I make my service walkthroughs here on WRT, and that is why I always include the sentence "this is not a tutorial".

[oldhippy]

I haven't watched the video. I can tell you in many cases you can not simply knock out a balance staff, some are riveted, so you will need the proper tool to remove it or if you have a watchmakers lathe you can remove the rivet with a graver. 

[VWatchie]

42 minutes ago, oldhippy said:

haven't watched the video.

If you press the play button it will start exactly where the balance staff is knocked out, so you won't waste any time trying to find the section where it is shown. Of course, only if you care to!

 

I just asked the "watchmaker" at ChatGPT the following question:

"What is the safest way to knock out the balance staff from the balance wheel in a mechanical watch movement?"

And I was provided with the following reply:

"Secure the movement: Before beginning any work on the movement, it is important to secure it in a movement holder or some other type of stable fixture to prevent it from moving around or being damaged.

Remove the balance cock: Using a screwdriver, remove the screw that holds the balance cock in place. Gently lift the balance cock off the movement, taking care not to damage the hairspring.

Position the balance wheel: Place the balance wheel on a flat, stable surface, with the staff pointing upwards.

Apply pressure to the staff: Using a specialized tool, such as a balance staff removing tool, carefully apply pressure to the staff. The tool should be positioned so that it applies pressure to the staff near the rim of the wheel, rather than near the hairspring. Apply gentle pressure until the staff begins to move.

Tap the tool: Once the staff has started to move, gently tap the tool with a small hammer to knock the staff out of the wheel. Take care not to strike the wheel or the hairspring, as this could damage them.

Inspect the staff: After the staff has been removed, inspect it carefully for any signs of damage or wear. If the staff is damaged, it may need to be replaced.

Reassemble the movement: Once the staff has been removed and inspected, reassemble the movement carefully, taking care to ensure that all components are properly aligned and adjusted."

The answer reminds me of a teenager who thinks he already knows everything. I can't say I'm particularly impressed. Still, some good advice in there. I will give it that.