Balance wheel axle wobble normal?

[Pradeep Sarin]

Watch: Waltham wrist watch from about 1950's.

Used to work fine.  Opened it up to clean the crystal from the inside and the dial. Now the problems are:

 

1: Runs face up, but not face down (the hands are off, so its not the hands sticking.

2: One jewel fell out - can't figure out where its from!

3: Examined the balance wheel motion under a microscope (when its running facing up. A slight wobble is noticed. 
     Video is posted at: Link to video of waltham wrist watch balance wheel wobble (watch face side)

     Zoomed in video at: Zoomed in view of balance wheel axle wobble

4: Is this wobble normal? Is there a jewel supposed to go in there, holding the pivot in place? 

 5:  For comparison, here's a view of the balance wheel axle from the back side of the watch, where there is a jewel in place:

    balance wheel axle from back side of the watch

      

And here's a  zoomed picture of the the jewel that fell out: it's 1mm diameter, and has a 3 pronged sleeve around it:

dropped jewel

 

Questions:

1:  is the balance wheel axle wobble normal?

2: Where does the jewel go back in?

 

I am a first time poster to this forum, so please be gentle. Have a liking for old mechanical watches (and old things in general). I do have access to fairly sophisticated workshop facility in my lab, so I can make whatever tools are required to press-fit jewels etc.

[Ado213]

Hi

Yes you  have a balance wheel jewel and cap jewel missing from the mainplate side of the watch. The balance wheel jewel is a press fit into a brass "chaton"  and the cap jewel sits on top of the chaton you should also have a shock spring which holds the balance  jewel, Chaton and cap jewel in the Block

[ceejay]

The jewel that had came out is called an end stone. 

Be very careful, there are at least 2 separate pieces (possible 3) that looks to be held together by old oil. 1.Cap jewel 2. setting jewel 3. captive spring.

 

You need to very, very carefully stop the balance rotation (it can be done whilst moving but is trickier) a small piece of rodico or similar can be used)

 

Now, on the plate where that jewel has came out is the circular 'setting' that has a tiny notch. you have to carefully drop the jewel into place and then feed the 3 legs of that 3 prong captive spring into that cutout notch, rotating as you go until all 3 legs are in place (there is a tiny groove in the plate)

 

My advice is to do this under some clear cling film and form a tiny circular piece of wood with a flat bottom to help you keep pressure on the spring and rotate at the same time.

 

Very tricky...Good luck!

 

EDIT: In your first video, you can see the cutout notch at the 12 o'clock position.

Edited March 24, 2020 by ceejay

[Pradeep Sarin]

Thanks for the detailed tips! This the perfect thing to occupy my time while we're locked down at home... Will try re-seating the jewels very very carefully. 

[Pradeep Sarin]

Update - after struggling with this off and on, in the middle of coping with life in a lockdown.... havnt made any progress.

The balance wheel jewel I have (I'm sure it fell out of the watch movement during disassembly) has 3 prongs on its chaton. (Pic below). 

It doesn't match the balance wheel jewel and chaton 3+4  in Ado123's top down diagram above.

 

AND I'm missing the shock resistant retaining spring + capstone jewel. Any ideas on how this assembly goes back to together?

 

Chris Carey at Watertown Watch Repair Co serviced the watch for me soon after my wife gifted it to me for my 35th.. 

We lived in Cambridge back then.

Now in hot, humid India - it's only needed a strap replacement in the last 12 years or so.

And now this catastrophe just at a time and a place where I can't get any parts..

 

[Ado213]

that is the cap jewel with attched shock spring is the watch a Seiko

[Pradeep Sarin]

No it's a Waltham Wrist Watch (photos attached below). The other side of the balance wheel shaft on the back is also set in a similar 3-prong jewel. 

[Ado213]

so you have the balance cap and shock spring attached, but no balance wheel jewel?. This will be difficult to find as it has to fit both in diameter and depth

[ceejay]

1 hour ago, Ado213 said:

so you have the balance cap and shock spring attached, but no balance wheel jewel?. This will be difficult to find as it has to fit both in diameter and depth

 

Spot on, the balance jewel is missing. 

 

For your information, the movement you have is a FHF 76. Unfortunately, it appears to be an unusual variant as it has this tri-shock protection. Most, according to google and Ranfft ( http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&FHF_76 ) have the common Incabloc shock protection. 

 

Unless someone else has a solution? You could take a chance on this... https://speedtimerkollektion.com/shop/product_info.php?cPath=32_222_100&products_id=19233 

It has the Incabloc protection. There is a 'chance' that the balance jewel will fit and you can then install your tri-shock end stone.

There is the possibility it will not fit and you may be able to use the entire mainplate, although it looks pretty shabby.

 

Anyway, you now know what your movement is & what is missing. 

 

 

 

[Pradeep Sarin]

Thanks all, for all the info.  

 

Now I vaguely recall  Chris @ Watertown watch said that some of the FHF76 movements put in Waltham watches during and just after the war had tri-shock protection due to shortage of Incabloc parts.

So now I know I have a particularly hard to fix watch with hard to find parts. Will have to wait till the antique shops around here in Bombay open up - then I will have to go hunt for a matching jewel. 
If it's approximately the right size I have all the diamond nano-machining tools in my lab to polish it to shape. 

Any tips on how to find the exact dimensions required?

[Pradeep Sarin]

Looks like this parts watches auction has a 1677 movement with tri-shock spring protection on the cap jewel :

 

https://www.ebay.com/itm/WALTHAM-Vintage-Used-Winding-Watch-movement-For-parts-Replacement-Varieties/174081741810?hash=item28881493f2:g:n3wAAOSwU~Ves1OV#shpCntId

 

What are the chances of the 1677 balance jewel being a close match to the FHF76 ?

[ceejay]

"close" won't be good enough. It has to be exact. That movement is a AS 1677. 

Chances of a match...no idea! Remote i'd say.

 

The jewel is set in a brass setting so polishing it to size is not possible.

 

Communicate with this guy... http://www.obsoletewatchandclockparts.com/wristwatchmovementsFto.htm

 

Explain what you have and what you need, he may be able to help.