Elgin Grade 542

Here's an Elgin grade 542, a 10 size, 17 jewel, movement, made about 1947. 

Next it needs the balance staff, and one balance jewel replaced.

The replacement staff I found for this watch needs a bit of work.  I will polish the pivots, and put a fresh shine on the body.  There is just a touch of rust on this part, but it is easily removed.  It's common to have to clean up, finish, polish, or even refine the size of replacement parts, even original factory parts.

The old staff is cut away, and the new staff is riveted to the balance wheel.

I like to seat the roller table so that the jewel is 90 degrees to the arms of the wheel. I see them seated all over, just any old way. It doesn't make any functional difference, but I think it's neater and it makes it easier to judge the position of the hairspring, to set the beat.

The hairspring has to be installed rotated with it's stud in the right place. The hairspring collet is friction fit to the staff, and so it can be turned (with the right tool). The stud, at the outside of the spring's coils, is held fixed by the balance cock when assembled. The stud has to be positioned such that the spring's at-rest position places the roller jewel dead center in the also dead centered fork.

Having set the roller table so that the jewel is 90 degrees to the arms of the balance, the balance wheel arms should be perpendicular to a line through the balance jewels, the pallet fork jewels and the escape wheel jewels.

If this is not right, then the balance wheel, when running, will turn more to one side than the other. A watch like this is said to be "out of beat". It will keep time poorly, and may even stop.