This one was a challenge since you don't expect to find a manufacturing defect in a 112 year old watch. I hope you can see the problem in the pictures. I was going to tell you what it is, but let's have some fun and see who picks it out first. Then I'll tell you more. The watch is an 18S Illinois.

Picture Two

Picture Three

That is the lower Balance Jewel holder and the bore is about 2-3 degrees out of square. As that is a clearance cut, it should not be a problem. It also appears that the facing cut is out of square the other way. However as the Pivot and Cap Jewels are inserted from the opposite side their accuracy depended entirely on how well the machining clearance for those were done on the other side.

David,
You don't think the tilt to one side or the yaw would throw off the angle of the pivot?

Dave has correctly identified the part and what is wrong with it...BUT, this did indeed cause a problem with the watch so we'll keep this going to see if anyone can figure out what the problem was.

Patrick...that wasn't the problem.

If the entire Jewel mounting pad extending out from the body is tilted the same as the finish cut of the pad faces, that can cause the Pivot jewel bore to be tilted about 3-5 degrees from perpendicular which can affect the freedom of the Balance wheel action in those "tilted" jewels. A "Brain Bump", I said cap, I meant Pivot Jewels. as edited above.

Also if extended out far enough the Roller Jewel could be obstructed.

Dave is getting very close. Hint...the top and bottom of the part are perfectly parallel and the staff is perpendicular to both the top and bottom jewels.

Roger what would be the effect on the timing screws?

The problem had no relationship to the timing screws.

Single roller or double roller? if a double, is the safety pin the pallet fork hitting the bottom on one side when it snaps over?

Thanks,

Jared

Thanks for clarifying Dave, but I knew what you meant and the hint is the same.

Jared, It is a single roller...pallet not the problem.

You guys are soooooo close!

I'll give another hint later if no one gets the answer.

If the jewel holes were drilled with the part located on the other larger part of the holder they would be perpendicuar with the corresponding jewel.
On the other hand if the part was located on the smaller part that is milled off, the hole/jewels would be off compared to the corresponding jewel in the other plate and the pivot would either rub or not work at all unless a smaller dia. pivot was used.

If you're saying what I think you are, Ed, then see my post above. The jewels, both top and bottom are perfectly perpendicular to the staff. The part in question is parallel to the surface where the pins are and the surface where the jewel resides.

OK, another hint. The problem shows itself in a dial down position. It is fine in a dial up position and may or may not be a factor in vertical positions.

OK. I don't know much, but I'll take a stab at it. Does the roller jewel rub it in a dial down position?

Doug

No, not the roller jewel. Dave already hit on that one earlier. You're very close though.

If that top counter bore is that far off center, the roller could rub on the nearest non concentric side of the counter bore in the dial down position

Ill second the great topic. While Im not sure of the problem it would cause I will take a guess below.
I also think more posts like this on a even semi regular basis dealing with what problems some issues create would be a fantastic idea. It would help those of us who like to work on watches but dont have a ton of experience learn from those that do.

I will take a guess. Perhaps the roller jewel is hitting or scraping the lower holder when the balance spins counterclockwise face down. It looks like there is some kind of wear to the lower holder where the roller jewel might pass in a complete counterclockwise spin.

DING...DING....DING!!

We have a winner. Dave got it. The roller table was just touching the high spot on the area noted in the picture. See the bevel across the top? The roller table is meant to ride in that area and the bevel gives it free clearance. With the bevel high on the right side, the roller table was just able to brush against the high spot. Keep in mind, this was JUST BARELY touching, but in the world of watches, it is HUGE. I long ago started the practice of after tear down and cleaning everything taking apart the top and bottom balance jewels, cleaning and oiling them and putting them back in. Then after careful examination of the balance, pivots and hairspring, putting that back on the balance cock. Then the most important part...checking balance motion with no other parts involved. I put the balance back on the plate by itself and give a twist of the wrist to set it vibrating. I carefully watch motion in multiple positions and if there is any noticeable difference, there is a problem somewhere that must be addressed before continuing. This is much easier than putting everything back together, finding the watch doesn't run right and then trying to figure out where the problem is. It is part of the isolation process which should be part of your diagnostic approach to finding problems. Preliminary beat can be set easily at this point as well since you have a clear view of the roller jewel and banking pins. Thanks for the interest in my little contest and thanks for the kind remarks.

Roger, Thank you for the great lesson!

I have another question for you.

Can you explain the different reasons that this watch could have run for the last 112 years like that, and now quit? Like, could the the staff have finally worn enough for the roller to touch?

Thanks again!!

Wow I didn't see that "Focus Here" when I looked a few minutes ago!!

Regards,
Larry

Roger-

As much as I would agree their cut wasn't perfect on this and has some flaws, I think the simple answer to me is that someone put in a roller jewel that was too long at some point causing this problem to be a problem. I'm sure this watch left the factory running in tip top shape with a shorter roller jewel that allowed this issue to not be an issue. Is this how you fixed the problem?

Thanks,

Jared

Larry, I do have some thoughts on exactly that question. Glad you asked.

1. It's possible the watch always had a problem and just was never dealt with. (not likely, but possible)

2. It may have been re-staffed and the new staff was just different enough to make contact.

3. The owner or owners never left the watch dial down and there wasn't enough contact in vertical positions to make a big difference in timekeeping.

4. A small pit in the cap jewel could allow it to drop just enough to start touching (I didn't notice a pit).

5. As you suggest, the tip of the staff could have worn just enough to allow it to touch. (not high on my list, but possible)

Can anyone suggest some other possibilities?

Oh...I had a bit of trouble sizing the 'focus here' picture, so I had to play with it before I got it to where you could see it. You probably caught one of my earlier attempts.

Jared,

The roller jewel wasn't even close to coming in contact with the high step end of the poorly machined part. As Dave correctly identified, the roller table was making contact. A little judicial removal of material with a dental burr from the pictured part on the high side and the watch has been running fine ever since. I might add that during my initial balance test I could actually HEAR the problem. I didn't know what it was initially, but I have a habit of putting the movement up to my ear when I'm doing this test. I knew right away that something was wrong...I just wasn't looking for a manufacturing defect.

Roger-

Thanks for the response. I thought david was talking about the roller jewel when he mentioned the roller. I understand now. My assumption would be a different staff that seated the roller table either a little higher or lower. over this many years though, it could be a combination of the items you listed causing it too.

Jared

Jared...I went back and highlighted the word 'table' since it is easy to confuse the jewel and roller in a discussion such as this. Thanks for pointing it out. I agree that the most likely cause was that a different balance staff initiated the problem.

Thank you again Roger.

When you took something off the roller did you have to make other adjustments to the timing, or was it still close enough to the center of the balance that it didn't affect it?

Regards,
Larry

Larry, I should have been more clear...I did NOT remove material from the roller table...I removed it from the pictured part. I'll go back to my earlier post and clarify. Thanks.

I suspect Roger removed material where marked in RED below to allow better clearance for the Roller TABLE(Nomenclature! Humpf )

Dave, That is correct and I probably removed more than I needed to, but as you stated early on this bore area is not critical so much in size as it is the way it was done. I have seen the roller table referred to as just 'roller' in many books so I don't think that reference is at all inaccurate. For clarification here, since most know it as a roller table, I changed it.

This was fun Roger, and I was just joking about Nomenclature which some think separates the "Experts" from the "Grunts".

Just a question Roger, is the area I circled showing wear marks, or is it just reflection?
If its wear, what do you think caused it?