I have finally got up the courage and tools needed to try and replace my first balance staff. The watch is a Illinois 16s 21j Time King serial # 5027275. But I am running into difficulty understanding exactly what staff fits this movement.
First I looked in Shugarts and determined that the movement is a model 9 lever set. I then looked at the 1923 parts catalog that is in the technical library. But there are 2 staffs listed for the 9th model 6893 and 6894. How do you determine which one it is?

Jim-
The difference is in the diameter of the staff where it passes through the balance. The 6893 staff is straight to the conical part of the pivot, and the 6894 staff is stepped. On p76 of the parts catalog, you can see the difference on the left side of the staff drawings. You may have to remove the staff to compare to the drawings.

Regards,
Bob

Hello Jim,

Make sure that with your lathe work you have a sharp carbide graver to cut away the riveted portion of the existing staff (on the upper end beneath the hairspring collet) before staking it out; if you force it out without doing this, you will spread the hole and distort the balance. I'm thinking you already know this but if you don't, just remember that the old staff should come out easily if the rivet is properly cut away...and this will allow the new staff to fit in accurately, providing all mating surfaces are clean.

Good luck.

William

Thanks for the advice Bob and William

I took the old staff out, and that solved the question of which staff.
I dont have a lathe yet (cant afford one at the price they go for)but the staff didnt look riveted in. It came out quite easily with a staking set and the staff removal tool with a light tap. I hope I didnt mess things up now. But the balance looks good and not bent or distorted in any way.

I also now have a question about diffrent part numbers. I have seen numbers on the balance staffs that start in 47xxx is there a reference for these numbers?

Jim, We have a short post on how to use the K&D Staff removal kit to safely remove riveted staffs by means of shearing the "rivet". Used on factory riveted staffs produces a "mini-washer" which is in fact the sheared rivet "ring" This kit was created by K&D to simplify staff removal without damage to the Balance staff arm. Check it out at

https://ihc185.infopop.cc/eve/f...26047761/m/798100603

Also there is a good looking K&D Balance staff removal set within instructions on eBay right now at;
http://www.ebay.com/itm/Pocket...&hash=item519ad342c8

Thank you Dave,
I used your excellent instructions on how to remove the staff when I did it last night. They helped a lot. I have a K&D balance staff remover and another roller table removal set that I dont know the manufacturer of that I used. I dont think anything is damaged, but I will see when I get the staff.

Well, I got the staff in a few days ago, but finally got the time to install it today.
I followed Fried's Watch Repairers Manual. Its now ticking away like a champ, the balance is spinning very nice. All in all it wasn't that hard. Finding the right replacement jewel for the bottom (the old one was broken) was the hardest thing.
This opens up a whole new option for me. I no longer will fear buying a watch with a broken balance if I can get the staff and the price is right.

Good work Jim, I am very glad you were successful.

Thanks Dave, I know I am a novice at repairing watches. Every broken one I fix brings a smile to my face when they work like they should. Ill post some pic's once I get it back in the case.