Hi, I have just aquired a Waltham 16S Model 1908 movement & the balance staff has a bent pivot. I would prefer to replace the staff as opposed to try & straighten the pivot. Would a Waltham expert out there have the part number I need to track down the correct staff?? The movement number is 17418312. The roller jewel has also been broken off. Is this an easy part to obtain? I've read a few posts about how to replece them, but it seems like a job for a more experienced person than me!

Best Regards, from Sydney Australia

Hi Philip,

I'm not an expert but I have the numbers for the balance staff(s) your looking for:

#4860 Balance Staff, Detachable, Straight Shoulder.

#4861 Balance Staff, Detachable, Taper Shoulder.

The one I replaced on my Model 1908 was a taper shoulder. It was also missing the roller jewel which took me a long time to get. They're pretty scarce. There might be someone on this MB who has one available... maybe.

Just in case:

#4957 Roller jewel or Jewel Pin.

#4957A Roller Jewel or Jewel Pin, Sapphire.

#4958 Roller Jewel or Jewel Pin, Short, for Steel Double Roller Escapement.

Good luck to you and if the people on this board can help further - let us know.

Hi Tim

Thanks for your quick response. How do I know if I need the straight or tapered staff? I have removed the hair spring & collet, will I have to remove the balance wheel & then measure the shaft from the top to the seat & see if it's tapered or straight? Or is there an easier way to tell??

Regards, Phil

Either staff is a friction staff. I happen to have a photo of a 4860 (straight shoulder) partially driven out of its hub in the balance wheel. You can see the straight-sided shoulder just where the staff narrows. The roller table will have a large hole that fits over this shoulder. The taper shoulder is much smaller and when seated is flush with the blued hub in the balance wheel. The roller table for the 4861 will have a smaller hole and fit on the smaller diameter part of the staff.

This illustration from Waltham's Watchmakers Handbook shows the 4861 (taper shoulder staff).

Nice explaination Jerry.
Philip, when you find which parts you need, e-mail me. I may be able to help.
Brian C.