No Side Shake

[Nora]

Hello All

I've changed the balance staff and trued the balance wheel in an Elgin 12s grade 303. The staff binds in the last 16th turn till tight of the cock screw. The wheel can be easily turned but does not spin freely. With out the staff in, the cock tightens an 8th of a turn past the binding point. The problem is that there is no side shake in the last bit. I found that when the cock has been tighten the staff will stick in the cock jewel. My first choice I feel is to shim the cock, but what type of stock should I get? Also what is the best way to trim it to shape? The thought of some type of broach to open the one end of the jewel also crossed my mind. but what type of broach? All of what I see for sale new just refers to use on metal.

Thank you in advance

[rodabod]

Is there any evidence that the balance cock has been bent, or if there are any file marks or punch marks underneath the balance cock?

[anilv]

On newer watches where the jewel is pressed into the mainplate it is possible to press the jewel in a bit to achieve the required endshake.

Im not familiar with the Elgin 303 but I would also check if the balance jewels have been swapped round as this can cause problems if they're not identical.

Another thing to check that the roller jewel interacts correctly with the pallet fork. If the staff is too long on the mainplate end the roller may only contact at the tip of the jewel instead of in the middle, shimming the balance cock wont help improve this.

Good luck.

Anilv

 

[Nucejoe]

Is staff shoulder curved on this?  Dose staff get stuck to the jewel on cock side only?

If staff shoulder and jewel face are not compatible( shoulder curved and jewel face flat) , you should see excess variation in FU position, even when you do create some end shake.

How are jewels to be moved if secured in place by screws? 

If pivot is bent, TG would show it as you increase the end shake.

 

 

[JohnR725]

when you replace the staff did you measure the old staff versus the new staff? then what was the actual staff number you used? Also are you aware of that Elgin staff numbers are not unique parts? In other words typically with each of their balance staffs the pivots sizes could very. So for instance for the grade 303 your staff numbers 2802 which came in four different pivots sizes.

unfortunately unlike Swiss watches where one staff is probably the right staff American pocket watch staff replacement has issues. It's why it's very important to measure all of the dimensions of the old versus new staff to avoid unpleasant surprises. That's because there are variations in sizing not just with the pivots size. Then a lot of times with modern replacement staff's rather than having four different pivots sizes they will just have a large size and allow the watchmaker to reduce the pivots to fit their watch.

 

[Nora]

16 hours ago, anilv said:

 

Im not familiar with the Elgin 303

 

 

The 303 is Elgin's base model  OF 12s produced between 1904 -1940.  It has 7 jewels and a nickel finish 

[Nora]

14 hours ago, Nucejoe said:

 Dose staff get stuck to the jewel on cock side only?

 

Yes, and only when tightened fully. I haven't installed the hairspring  yet, nor is the fork in either.  After the balance becomes to stiff to turn freely it will come out with the balance cock.  

[Nora]

22 hours ago, rodabod said:

Is there any evidence that the balance cock has been bent, or if there are any file marks or punch marks underneath the balance cock?

No everything looks 

[Nora]

11 hours ago, JohnR725 said:

when you replace the staff did you measure the old staff versus the new staff? then what was the actual staff number you used? Also are you aware of that Elgin staff numbers are not unique parts? In other words typically with each of their balance staffs the pivots sizes could very. So for instance for the grade 303 your staff numbers 2802 which came in four different pivots sizes.

Yes I measured them. I ordered 6 2802's to start with and sifted threw them to find a match. I was not aware that there are 4 pivot sizes. All of what I received have an OAL of .162" with a   pivot diameter of .004". So I just went with it. There was nothing for me to compare with the pivots, both ends from the original were missing. What makes them different is the shoulder dimensions. 

Are you aware of any listing that shows the pivot sizes options for  each watch type? I got the staff part  number from https://pocketwatchdatabase.com/  but as you pointed out there are 4 sizes of 2802 staffs. The side note said  "See notes on Balance Staffs in Special Information Section". However that made no mention of any variations.

[Nucejoe]

49 minutes ago, Nora said:

Yes, and only when tightened fully. I haven't installed the hairspring  yet, nor is the fork in either.  After the balance becomes to stiff to turn freely it will come out with the balance cock.  

Pivot shoulder might partially be entering the jewel hole and stick to it, I examine the jewel under magnification for sign of damage. No need to remove the jewel, just view it from under side of the cock.

Jewel hole might be way larger in diameter than pivot, in which case you should feel excess side shake when cock is not fully tightened.

Dirty upper jewels is likeliest and most common cause.

[Nora]

24 minutes ago, Nucejoe said:

Pivot shoulder might partially be entering the jewel hole and stick to it, I examine the jewel under magnification for sign of damage.

I believe this may be true. All looked well with 10x. So I removed the cap jewel then reassembled. If the pivot jewel is seated fully it will bind. With slight movement of the balance wheel to  dislodge the jewel it will spin freely again. However it will bind again under the weight of a 2 mm pegwood.

[HectorLooi]

Looks like it's time for you to get a jewel hole gauge, a watchmaker's lathe, cutters, files, burnishers and start polishing down your pivots.

[Nucejoe]

2 hours ago, Nora said:

I believe this may be true. All looked well with 10x. So I removed the cap jewel then reassembled. If the pivot jewel is seated fully it will bind. With slight movement of the balance wheel to  dislodge the jewel it will spin freely again. However it will bind again under the weight of a 2 mm pegwood.

You might furthure narrow down the fault  by switching the upper and lower jewels around, then if staff still stick to the cock side, the cock itself might be bent, if it sticks to other side the fault is with the jewel. Bent pivot is very common. Both jewels should look the same, oil cups shouldn't face the pivots. Its either by elimination or visually spotting a fault.  

[Nora]

1 hour ago, HectorLooi said:

Looks like it's time for you to get a jewel hole gauge, a watchmaker's lathe, cutters, files, burnishers and start polishing down your pivots.

I'm hoping for next year. I have more learning to do before I make that plunge financially.

[JohnR725]

2 hours ago, Nucejoe said:

You might furthure narrow down the fault  by switching the upper and lower jewels around, then if staff still stick to the cock side, the cock itself might be bent, if it sticks to other side the fault is with the jewel. Bent pivot is very common. Both jewels should look the same, oil cups shouldn't face the pivots. Its either by elimination or visually spotting a fault. 

as a reminder this is an American pocket watch swapping the jewels around doesn't always work because they're not always the same size. Then bent pivot shouldn't be an issue for a new balance staff hopefully.

pocket watch database is a good source for watch parts. If it's an Elgin watch you know the grade number this is another place to look although it does have a minor issue.

http://www.elginwatchparts.com/Script_Find_Grade.php

the minor issue is there's a reference to the notes found at the bottom of the page. Like for instance those balance hole jewels that somebody claimed were identical don't appear to be identical depending upon your serial number. Then there's a reference the balance staffs but that refers you to another section that doesn't exist on this page.

if you're going to work on American pocket watches there is a definite must-have reference book that almost no one has ever heard of which is Swartchild & Co Chart Book for American Balance Staffs. There is also a second book that has the jewels listed. I miss snip out the section on the balance staffs for you.

https://www.ebay.com/itm/Swartchild-Co-Chart-Book-for-American-Balance-Staffs-reprint/162769575312?hash=item25e5d29d90:g:zhoAAOSw1HtfGEpv

then I'm attaching another image another way to tell if your staff is sized correctly for the whole although you do need to do this test before you've attached the balance wheel it's a little hard with the balance wheel on.

 

 

 

 

 

[Nucejoe]

2 hours ago, JohnR725 said:

as a reminder this is an American pocket watch swapping the jewels around doesn't always work because they're not always the same size. Then bent pivot shouldn't be an issue for a new balance staff hopefully.

pocket watch database is a good source for watch parts. If it's an Elgin watch you know the grade number this is another place to look although it does have a minor issue.

http://www.elginwatchparts.com/Script_Find_Grade.php

the minor issue is there's a reference to the notes found at the bottom of the page. Like for instance those balance hole jewels that somebody claimed were identical don't appear to be identical depending upon your serial number. Then there's a reference the balance staffs but that refers you to another section that doesn't exist on this page.

if you're going to work on American pocket watches there is a definite must-have reference book that almost no one has ever heard of which is Swartchild & Co Chart Book for American Balance Staffs. There is also a second book that has the jewels listed. I miss snip out the section on the balance staffs for you.

https://www.ebay.com/itm/Swartchild-Co-Chart-Book-for-American-Balance-Staffs-reprint/162769575312?hash=item25e5d29d90:g:zhoAAOSw1HtfGEpv

then I'm attaching another image another way to tell if your staff is sized correctly for the whole although you do need to do this test before you've attached the balance wheel it's a little hard with the balance wheel on.

 

 

 

 

 

Is staff replaced with the right one? Are jewels, pivots and the cock perfect?  A host of possible causes are to be checked in the hopes of finding the fault. 

Regards

[Nora]

Thank you all for the useful  information! I have found the definite problem that is causing it to bind.  The pivot is indeed to large for the hole in the jewel. I took one of the other staffs with the same sized pivots and tried putting it in the hole with the balance cock flipped over. It comes nowhere near the shoulder, but binds up on the pivot itself The staffs that I've got are generic  from an eBay store. I don't mind the outcome. I have learned a lot about what more I need to learn /get to make it happen. I'll come back to it again as a future project.  

[MechanicMike]

On 8/6/2020 at 5:03 AM, JohnR725 said:

when you replace the staff did you measure the old staff versus the new staff? then what was the actual staff number you used? Also are you aware of that Elgin staff numbers are not unique parts? In other words typically with each of their balance staffs the pivots sizes could very. So for instance for the grade 303 your staff numbers 2802 which came in four different pivots sizes.

unfortunately unlike Swiss watches where one staff is probably the right staff American pocket watch staff replacement has issues. It's why it's very important to measure all of the dimensions of the old versus new staff to avoid unpleasant surprises. That's because there are variations in sizing not just with the pivots size. Then a lot of times with modern replacement staff's rather than having four different pivots sizes they will just have a large size and allow the watchmaker to reduce the pivots to fit their watch.

 

bingo. working on an Hampden a few weeks ago shaking my head in utter confusion staring at my bench....then found out exactly what you said. there's a guy in Ohio I get my stuff from says he has all the old Dueber-Hampden stuff from parts left over after the move to mother russia.  staffs are all over the place. in the beginning he had had the same problem. had to measure and  fit up staff to cap and pinion jewels, both top and bottom. got passed that, worked like butter. gave me a helluva headache tho.

[MechanicMike]

2 hours ago, Nora said:

Thank you all for the useful  information! I have found the definite problem that is causing it to bind.  The pivot is indeed to large for the hole in the jewel. I took one of the other staffs with the same sized pivots and tried putting it in the hole with the balance cock flipped over. It comes nowhere near the shoulder, but binds up on the pivot itself The staffs that I've got are generic  from an eBay store. I don't mind the outcome. I have learned a lot about what more I need to learn /get to make it happen. I'll come back to it again as a future project.  

ain't it fun?! was at the same point you are just days ago. John has some great references for keeping at hand. that diagram he shared is exactly part of the info that helped me when I was stumped except I got it out of a copy of the Chicago School of Watchmaking. I learned this from an old retired repairman when I bought his old staking set. Warning! as I was told, don't attempt to read it. there is just to much to try and soak in, the book is huge. instead he said, dig into your watches, and reference it as you go along. Otherwise he said, "you'll go nuts!" he was right. it works for me. enjoy.

Edited August 8, 2020 by MechanicMike
wrong name!