Antique Pocket Watch Identification and Restoration

Wow! The engine compartment looks spotless!

 

There are a few “battle scars”. Arrows here are pointing to wear marks in the pocket where the mainspring barrel resides. The red is likely the result of dirt getting into the grease that lubricates the shoulder of the arbor where it pivots in the main plate. The yellow points to where the ratchet wheel teeth have rubbed against the main plate over the years.

There’s not really anything that can be done to address this without welding or brazing new material on, smoothing, and replating the whole thing with fresh nickel. If the goal was a factory refresh, that’s what we’d do... and I’d have to buy plenty of new tools. There’s no need to address them with anything other than a proper service.

Besides, this is an heirloom though and every little scratch, dent, and wear mark holds a story, a collection of memories of another time and another owner. If this watch could speak... what has it witnessed? What events was it a “fly on the wall” for? Weddings, births, business deals?

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I love this thread. The intricacies of mechanical watch internals always amaze me. Thanks for letting us tag along on your adventure Phil and Rich.

 

Right now, its just a waiting game. Waiting for the crystal, waiting for the mainspring, waiting for the tool to extract that broken screw from the main plate.

The one thing I can work on is that wonky balance. I've read a few different ideas but I don't really trust any of them and they were not descriptive enough for me to want to attempt them.

 

Rich,

Have you considered applying a little heat to the balance? My thought would be: oven at 500 degrees. Something uniform and low temperature may be enough to address the hardening and issues from prior sins without the risk of a torch or soldering iron. Also, the wheel should be replaceable, if necessary.

Regards,

Art S.

 

I had been thinking about heat but had no idea what type of temps to try so that is extremely helpful, thank you. I will have to defer to Phil about replacing if I cannot get it straightened or perhaps get the part to someone more skilled in this area than I am. Thinking about it more, it will be difficult to time if its not concentric as that's going to throw off the rotational inertia of the balance since the mass isn't being "hung" out as far from the axis. Correct? I suppose adding a little length to the hairspring could slow it down and compensate and there is a lot of extra hairspring past the pin but it isn't the best option.

I will try heating it this weekend as I'd be much happier to repair than to replace.

If necessary, do you have any suggestions as to how I could even find a replacement? We're having a devil of a time even figuring out who made it so I'm not sure how to source a part.

 

Rich,

Get me some detailed dimensions and weight and I'll see what I can do.

You should be able to straighten it. The heat is to help it and avoid cracks but I'd do a little homework on line (especially regarding time at temp) before proceeding.

Regards,

Art S.

 

Minor update: I've found someone with access to an adequately sensitive scale so I should be able to get that info to ArtS this weekend. The replacement crystal arrived today and looks to be spot on with the old! I have not mounted it to the bezel/case lid yet as I want to be sure that it doesn't touch the canon pin once everything is mounted. Getting so close!

 

Balance wheel is all prepped for transit to the weigh station.

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Any luck in identifying the maker?

 

Short answer, nope. Long answer, not even a little bit, nada, zilch.

Someone much smarter than I told me that they believe it is based on an ETA ébauche. The serial number is so low though compared to the expected date that it's throwing them off a bit as well.

 

Time for “good news, bad news”.

Good news: as I already had the balance wheel off I was thinking “how can I flatten this” and an idea came to mind. I used my jeweling set! I put a concave cone with a pusher and a larger diameter than the hub of the wheel on the top and a flat ended piece on the bottom whose diameter just matched the hub. Gently working the gap closed with the micrometer head... now we have a beautifully flat balance wheel!

Bad news: I think I figured out why someone would bend a balance wheel out of flat. The staff (the rod through the center of the balance assembly that everything pivots with) is bent. I will be measuring it to see if a replacement can be found and then attempting to tease it back to straight.

One thing leads to another. We’ll get there though, we’ll get there. Pictures to follow when I can get back to my bench.

 

Ok, took another look and I’m not sure what the deal is. Going to measure everything and take a couple days long break to clear my head and then look at it when I’m feeling fresh again.

Separately both parts look fine. Together, it’s like the mating surfaces aren’t level with each other or something. Going to need the microscope for this... again... my eyes and my loupes don’t seem to be cutting it.

 

I will not claim to have won the war but I believe I have found a winning strategy!



Look at that unimpeded oscillation! Yes, I'll admit, there's a bit of leveling left to do but I would like to wait until I have finished poising the balance & getting it in beat. The escape wheel is not in the movement at this time as I just wanted to see if I was getting the balance settled. One fight at a time.

Side shot of the newly and close to level balance wheel.
Before:
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Rubbing on the escape cock and WAY out of level.

After:
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There's no rubbing on the escape cock, the hairspring is also close to level and it is just a skosh cattywompus (highly technical terms so don't worry if you're having a hard time following).


The mating surface of the shoulder on the shaft which the balance wheel rests onto is simply not square to the axis of rotation. So when I have it set so it is properly self-starting I will finish leveling the wheel in that position and then adjust the timing.

 

As for my adjusting technique as described a few posts above: pictures 1-3 below show what I was trying to describe. Phil, I'm sorry I didn't take pictures with your balance wheel in the mix but I will try to remember to do so when I'm do the final adjustments. For now, this is a junk balance wheel from one of many Chinese ST36 movements (ETA 6497-2 clones) that I've taking apart and occasionally destroyed (on purpose) during my self-education.

1) Jeweling tool with the concave bit (with center pusher pump) on the left of the red block, flat one on the right.
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2) This shows how the bits are set in with the balance wheel resting.
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3) When you close down and apply gentle pressure, the center pusher pump sets the wheel into the center of the pieces. The edges of the concave piece apply pressure at the base of the arms where they meet the hub and gently adjusts all three to the same/similar degree.
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4) Now for the winning strategy. I used two different bits when I did this for Phil's component which allowed the balance staff to be supported in the middle but not be touched by anything. I gently applied pressure with tweezers to the arms until the rim of the wheel was as close to level as I could visually gage it to be. The result is what was shown in the video and images of the previous post.
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What a rollercoaster this has been!

 

Trying to follow up with that "JD" stamp and I've found evidence of a French watch maker in the late 1800's called J. Dejardins which utilized the mark of "JD" on their items. The website I found this on, Mikrolisk, does not have a graphic of the stamp so I don't know for sure if this is the same but it is a potential lead. This and the serial number being so low are making it look like perhaps the watch was purchased prior to immigrating to the USA or maybe purchased second-hand or possibly even inherited by your great-grandfather...

 

A beautiful new tool arrived yesterday. Bergeon’s No.: 30209 broken screw extractor.

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You mount the plate, or other part, with the broken screw as shown in the next picture with those two pins pushing on either end of the broken screw.

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The. You rotate the part, et voilà, the broken screw piece is backed out / removed. In this particular instance I did have to apply a small amount of precision targeted percussive helically wrapped plane disengagement... I hit the screw bit with a dowel pin and a mallet to loosen the threads.

That tiny little silver dot to the right of the main plate is the offending screw.


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One more step taken in the right direction!

 

Next up is seeing where we stand on having the balance properly setup. In this case, that means finding out how the teeth of the escape wheel (GREEN arrow) match up to the pocket in the balance staff (BLUE arrow). While the balance is at rest the leading point of the tooth needs to be able to enter the pocket on the entry side of the staff and the same on the exit side. The tooth is shaped like an arrow from above tapering outwards. The tapered edge applies a force to the edge of the pocket in the balance staff and that is what pushes the wheel into oscillation. It then rests in the pocket until the balance swings back the other direction where it applies torque to the exit side of the pocket. Then as they say, lather rinse repeat, and you've got your self a ticking movement.

I'm SO close after the first go round of adjustments but as you might be able to see as highlighted by the ORANGE arrow, that leading point of the tooth runs into the exterior cylinder of the staff by just a few degrees.

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Here is an over head shot showing the shape of the escape wheel tooth. The YELLOW circle is around one tooth with a LIME GREEN arrow indicating the leading point that has to get pas the edge of the staff pocket. You can really see that wedge shape I was talking about above. The ROSE arrow indicates the direction of rotation of the wheel.

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After adjusting the hairspring collet’s alignment with the balance staff, I think I’ve found a good point at which to begin getting the movement timed and in-beat. I could let the balance set at rest and with a gentle touch to the escape wheel it would advance into or out of the pocket. I gave the balance just a little tap to get it oscillating and then blew air (gently... noticing a trend here?) on the escape to make it rotate as it would if the movement were functioning and it continued to advance as well as the balance continuing to oscillate.

Time to move back to my personal projects for a bit while we wait for the remaining parts to arrive.

*Note: being “in beat” means that the balance oscillates the same amount, as measured in degrees, in each direction from rest. If it goes a little further in one direction that the other the time between the tick and the rock will be different that’s that between a tock and a tick. This means that you’re not evenly applying force / torque / impulse to the balance in each direction.

 

Found this, case number is 42390, again not sure if relevant, but:

https://www.bukowskis.com/en/lots/1023579-fickur-49-mm

 

Still waiting on that new mainspring to arrive. After checking my stash of random watch screws and coming up empty, I turned to Google and eBay this weekend looking for a replacement dial foot retaining screw but couldn't turn anything up. Looks like I have my opportunity to leave my mark on this movement after all! I think I'm going to halt the search and plan on making a replacement.

Sadly, it doesn't seem to be related.

 

I was surprised to find that I’d received a parcel from the UK today and thrilled to find that it contained the replacement mainspring for this project! I’ll have to modify the end to work with this barrel, but that means I have no excuse not to start putting it back together! Plus, I needed a bit of stress relief this evening so I went down to the lab for a while.

Dial side progress:
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Back side progress:
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Woot! I'm oiling as I go. Since I do not have a service manual for this movement (not the least of the reasons why being that we still haven't identified the manufacturer! AUGH!) I've been making educated guesses on which lubricant is appropriate. This isn't without rationale though, I'm reading through several different movement service manuals and going with the one that seems to have the most related to the part I'm working on. Luckily, they seem to match up pretty darn well so there's not much left for me to "figure".

The best piece of news I have is that if I hold the hub of the center wheel (aptly named as its in the dead center of the movement) and apply a torque in the CCW direction (we're looking at the back of the movement so that correlates to CW on the dial side... which is what we want), the balance wheel jumps right into motion! I'm definitely not putting as much torque on it as a fully wound mainspring will but it sure looks promising and definitely made my evening.

 

Had sometime to kill last night. I found that Jules Jurgensen pocket watches have the same characteristic "jester" in the movement. While I couldn't find anything with 42390, here's a sample of the JJ movement, other samples can be found if you search:

https://www.invaluable.com/auction-lot/antique-jules-jurgensen-copenhagen-pocket-watch-m-109-c-190447e8e0