I have a Elgin grade 86 convertible movement with a broken balance staff. I have purchased three 861 staffs and none of them have the dimensions of the original staff. I have enclosed an image. Bottom is 861 old style then 861 new style, then 861 C then top is the original staff. The original roller table only fits the original staff. The diameter of the roller table hole is 0.5mm and the diameter of all of the 861 purchased staffs are 0.6mm. The question is what to do? Find a roller table that fits one of the new staffs or alter the staffs (I would guess by thinning down the shaft so the table fits)?

Thank you,
Larry

I should add that the 861 c staff has the closest profile to the original staff from the movement.

Larry

Hi Larry,
From what I have found is that all the balance staffs for the 861 have the same size ( from .62 to .63 mm), for the roller.
It might be that this is not the original roller.
Besides looking for a new roller, have you considered boring the roller to .60 from the .50 mm that you have now.

Hi Larry,
Most of the early convertibles I have worked on have the smaller roller table holes. I always have to turn down the staff to fit the hole. Easier to get another staff than a table if you were to make the hole too big.

Steve

Here is a list of some common roller tables .
Perhaps you can find one that will suit the situation.

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