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Hi Guys,

I'm working on a Ball 999B 16s PW; serial 1B7401 .  The balance staff is broken as is the hour hand.  I can't find any information on replacement parts for either, with one exception.  I read on a forum that the more common 992B movement has the same staff as the 999B.  If they are the same, I think that Dave's has it, but he could not confirm if this is the case.  Does anyone know if this is true; or otherwise have a lead for obtaining a new balance staff.

Also, Dave has hands that are similar that are for an Elgin 16s.  Without knowing the diameter of the holes on Dave's hands, does anyone know if they fit my watch (or if you have another source for hands that will fit the Ball).  I looked at esslinger and cas ker but didn't find anything.

Thanks guys.

ham hands.png

ball mvt.png

ball elgin hand.JPG

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the easiest way to tell what staff you need is to remove the staff you already have. Then if it's like a 992B staff it should be a friction staff so be careful and don't knock out the blue hub it frictions into.

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Thanks guys.  I wondered what the blue hub signified.  I found  a reference and diagram for removing the friction fit balance staff.  Here's the link to the chicago school of watchmaking chapter that discusses it.  http://www.rdrop.com/~jsexton/watches/csw/les15/index.html#:~:text=It is quickly recognizable by,as in figure 15-8.  I was looking forward to using my lathe to cut off the hub, but it looks like this will be easier.

So my plan is to send a picture to Dave to see if the 992B staff matches up.  Does anyone have a diagram of said staff?  Esslinger shows it in stock but it has no diagram.

Enjoy the weekend.

chicago chapter.png

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Just a reminder this is watch repair there are lots and lots and lots of variations. Your friction staff is a Waltham friction staff in the image up above requires special parts for your staking set. Hamilton used a different arrangement like the image below. Even though there's a groove showed in the staff the 992B does not have. So you can see the hub on the left staff in the middle and how they would look together. The reason for this particular example in the book was that they were some watches that they had upgraded the friction staff and they put the groups of people with no beyond the blued hub what was going on but on the watches like the 992B they didn't do the


5 hours ago, arron said:

So my plan is to send a picture to Dave to see if the 992B staff matches up.  Does anyone have a diagram of said staff?  Esslinger shows it in stock but it has no diagram.

Dimensions would be better because there are some minor variations.

For instance of the friction staff's there are three of them at least for the 16 size 2 of them are the same for size with the pivot difference in the 992B only comes in one size


So visually though staffs will look identical casually at least.

So here's what your hub looks like with the Hamilton staff. As you see is a lot easier to work with them the Waltham all you have to do is support the blued steel part and gently knock out the friction staff from the other side of course


In other words on the staking set it will look like this.


A picture of the staff


A picture of measuring the staff which why would I do such a stupid thing is measured the staff? Because there's only 1992B staff there's no need to measure except there does seem to be some minor variations. I have a suspicion that some aftermarket staffs are not made quite the right dimensions and then they will not friction in the hub there too big or occasionally get one that loose because somebody drove a big staff in when they shouldn't have


Here's a picture testing the staff in the balance hole jewel even though there's only one size it's still nice to check before it's in the balance







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@JohnR725 that's very helpful.  I appreciate the time you took to give those instructions and post the pictures.  below is a picture of my staff, which looks identical to the ones you posted.  The approx measurements I got are: .772 on the left part of the staff; .715 on the right side of the hub; the hub is 1.107; and the overall length (minus the broken pivot) is 5.248; which seem to line up with the measurements you posted.  I didn't think to measure the pivot, which I'll do if there's enough of one left on the staff.  Thanks again.


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