The balance is from a 18S Home watch Co. movement.
Does anyone have advice on how to disassemble the balance? I have to replace the staff.
When looking at the top, the hairspring is below the balance wheel and I’m not sure how to start taking it apart. Are any special tools necessary?
I will appreciate any help.
Thanks,
Dan

Hi Dan, from what i know, and i am no expert on this.The roller table needs to be removed and yes a special tool for this job is used to do this.Some roller removal tools are more complex than others and the price of them varies also.The hairspring also needs to be removed to work on the staff and a special tool for that one.Sometimes the collet can be held by tweezers and twisted and it can come off.One thing to remember also is the roller table and hairspring have to have their positions marked so you can reasemble them in their original positions.
I hope this helps and hopefully if i have not explained this well, someone will correct or help more.

I don't think that I would use tweezers to remove the hairspring and collet - too much chance of it slipping and bending the spring. I use a tool that is like a very small screwdriver. It fits in the split of the collet and with a slight twist and upward lift it will break the collet free of the staff and lift it off. Anyway, that is what the books say, but it never works for me (the lifting part). It does allow me to turn the collet, though, loosening it enough to give me just enough room to get underneath it with the same tool to pry it up and off the shoulder.

For removing the roller table there are a variety of specialized tools. Most staking sets have the proper stumps and stakes to do it also. I suggest you check the procedures in "The Watch Repairer`s Manual" by Henry B. Fried.
For removing hairsprings I use a small tool I made for this purpose (ala Fried). It is used like a small "crow-bar" to pry the collet up and off. Place the balance wheel with hairspring up into the smallest size hole the other end (roller end) of staff will fit in to allow bal. shoulders to rest level on the flat anvil. It is best to have removed the roller table first. Use extreme care positioning the tool so prongs are securely under collet, so pressure will be on the collet and not the hairspring, before prying up. I`ve used this method for quite some time now and haven`t mangled one yet!
Make sure the tool and prongs are smoothly finished with no burrs to catch on the spring.
The dimensions in the pic are Fried`s but are not overly critical and can be varied a little.


Good luck!

Dan,
After looking at your pic a little closer I notice that this model looks to be "undersprung". I am not familiar with this type but would imagine the advice given by Jerry and I regarding hairspring removal, would still apply but the roller table must be removed first.
In my above post I forgot to mention that the tool should rest on top of one of the shoulder arms which is down flat on the anvil.
Also noticed in an old post by Steve Maddox that the staff for the model 57 might be hard to locate;

Home Watch Co.

Thanks Kenny and Jerry, like i said someone could help more than me.I would like to make the hairspring removal tool.The tweezers can slip and damage the hairspring, has not happened yet, knock on wood.
Henry Fried,s book is a good investment for anyone working on their watches.

All -

I use a pretty standard roller table removal tool on everything except these undersprung balances. For these, I use a very simple, effective, and safe proceedure:

• hold the roller table tightly in a collet on your lathe
  
• rotate the lathe by hand while pulling the balance gently away from the collet
  
• remove the hairspring using your favorite hairspring removal tool/method
  

When done carefully, you won't break the roller jewel, bung up the staff pivot, deform the balance, or bend the hairspring.

Of course, this method pre-supposes you have a lathe to work with. I'm afraid I can't recommend a safe method without either a lathe (it may exist, but I sure don't know it) or a special (and probably very expensive) roller table removal tool.

PROBLEM SOLVED!

First let me thank everyone who contributed to this post. I never expected such a large and complete response.
The problem was removing the roller table. Since it had to be done first with the hairspring still in place, none of my roller table removal tools would work.

I used the method recommended by Harvey Mintz in his post.
I put the roller table in a lathe collet and carefully removed the balance wheel. It worked great.

I also learned from your responses that the staffs for these watches are not commercially available. I’ll make the staff even though it takes me a very long time to do. I am happy again.

Again, thanks everybody,

Dan