Elgin Grade 287

Here we can see the pivots on the balance staff, broken.

The pivots are very small needles of hardened steel, and are easily broken if the watch gets a sharp jolt. Often the jewels that form the bearings of the balance also get cracked if something happens. But on this watch they are fine.

The old staff is removed in the lathe. The back hub is first cut down to almost nothing.

The replacement staff is riveted to the balance wheel.

This shows checking the balance, and the new staff, for free motion in the movement, prior to putting the hairspring back in place. In this case I had to slightly adjust the arms of the balance down, and then make sure it was true to round and flat again.

Then the roller table and hairspring are then installed and the balance assembly is complete.