Elgin pocket watch--cracked jewel, staff replacement, split roller...summary and question

[LittleWatchShop]

I started to tag on to this thread, but decided that it was unique enough to go alone.  I will leave it to the webmaster to move if necessary.

Back story: friend of a friend sent this with instructions not to bother to fix it but give her some info about the watch.  Naturally, I cannot run from a repair, so I have embarked on service.
It is an Elgin  12s pocket watch Grade 384.  Before posting I wanted to get the jump on the Ph.D. of Googlefu-database-master-of-all-watch-knowledge @JohnR725, so I did my own research using, in part, the Marshall Handy Manual...feel free to check my work

Balance staff was broken, and I found a cracked jewel.

Decided to tackle the staff first and then circle back to the jewel.  With the help of the Handy Manual et al., I found the part number and  Ofrei has it, so I can buy it for a small sum.  However, I have jars of staffs, so I decided to find one close and turn it to fit.  I found one that was pretty close and spent the next four hours on the lathe.  I shortened it, skinnyed it up here and there and did a test mount in the watch to confirm end shake.  I used my Dads Seitz jewel measuring tool to test the pivots as I was turning--far easier than using a caliper (110 um diameter...BTW, the bonding pad on an integrated circuit up until the deep submicron stuff is typically around 100um). I was feeling pretty uppity, thinking watchmakers have nothing on me.  Then, as the old scripture says, "Pride goeth before destruction and a haughty spirit before a fall."  Yup I fell pretty hard.  As you can see, the roller arbor diameter is 0.55mm,  I was at about 0.59mm or so and decided it was close enough.  NO SIR.  I split the safety roller.  That was pretty much the end of the day.  I was deeply humbled and deserved what I got!

Today, I am returning to this watch and putting my pride aside and considering buying the roller assembly and staff which I have found on the internet.  The staff is at Ofrei, and the roller on Ebay (and perhaps other places).

Here is my question.  Should I attempt to replace the cracked jewel?  On the one hand, I should, if only for the experience.  On the other, the owner really does not care (and I am not charging for my work...and my pay out of pocket for any parts I replace.

A penny for your thoughts on the jewel!!

2022-02-18 10_21_36-Elgin Grade 384 (Model 3) Parts for Pocket Watch_ Serial Number 20526801 — Mozil.pdf

[jdm]

3 hours ago, LittleWatchShop said:

As you can see, the roller arbor diameter is 0.55mm,  I was at about 0.59mm or so and decided it was close enough. 

0.04mm is high interference even on big and strong parts. How much is right is one of the most difficult things to judge and get correct. Better luck the next time.

[JohnR725]

5 hours ago, LittleWatchShop said:

cracked jewel.

Being nitpicky to start the day you probably should say balance jewel. Because we tend to end up with lots of flawed jewels in pocket watches.

5 hours ago, LittleWatchShop said:

Seitz jewel measuring tool to test the pivots as I was turning--far easier than using a caliper

Yes definitely nicer then some other measuring device including a micrometer because it's light weight you're less likely to do bad things.

5 hours ago, LittleWatchShop said:

As you can see, the roller arbor diameter is 0.55mm,  I was at about 0.59mm or so and decided it was close enough.  NO SIR.  I split the safety roller.  That was pretty much the end of the day.  I was deeply humbled and deserved what I got!

 

Rules when replacing American pocket watch staffs? The classic rule is to measure the old staff then of course measure the new staff and make sure they exactly agree.  Never assume when purchasing an American pocket watch staffs by a part number that it's just going to fit because there's usually variations. The most common will be pivots size variation but there will be other variations.

Then what's the next rule really important that you forgot about the parts Must fit. Typically if the old and new were identical they should fit but you still want to make sure they fit.

Most common places where fitting is a big issue is well everything on the staff to be honest.

Roller table normally witschi Delia put it on the staff in it has to drop a certain distance because it's slightly tapered shaft. Can't remember the exact drop but let's say around two thirds. As you discovered if you're back and then one half or one quarter category that's a heck of a lot of where Al yes that's a little too much if it goes almost to the bottom it might not hold tight. So some point in time when you're putting a staff together with the parts you have to make sure they actually seem to fit as opposed to whatever the dimensions are supposed to be.

Then I'm attaching an image of it noticed the very top of the image where it came from company that no longer exists. It's far as I know there are no PDFs of this in existence in the wild. I've occasionally seen it for sale on eBay is a printed copy. Tens to be quite good for dimensions. The reason I gave you the entire section is it a lot of the other staffs that are close and see which ones are you will be best to modify like the 1905 looks like one has a hub thickness bigger than yours just reduce at the FETs you'll be fine the other one is too small adding material is problematic the 1905 staff also demonstrates a problem with American pocket watch staffs which is their variations

like for instance at the site below it indicates there's a variation for your staff but it appears to be the only variation was the pivots. But the 1905 staff demonstrates variations for other stuff which is all too common very confusing to people when their brand-new staff by part number doesn't fit and they definitely did not measure it because why should they they have a part number part numbers are perfect

http://www.elginwatchparts.com/

 

Balance jewel? It's hard to tell from the image the flaw crack break that goes straight across as to whether that's going to be an issue or not? Usually if you look inside the jewel and the flaw is just a visual flawed not a huge crack it's not an issue. Sometimes you can even have a crack it just depends on which way it angles like in a train wheel pivots angled so it's not complaining like a metal plane the metal on the pivot and if you look at the pivot it looks perfect it's probably fine. Although people get upset about the flaws in one of change over jewels and considering these are mostly natural stones that's going to be an issue

 the chip on top this interesting of the? It's probably not going to hurt the balance pivot itself but it's definitely going to upset lubrication. Capillary action would normally keep the lubrication to the center of the jewel but with those chips it's conceivable your lubrication is going to wick away and disappear really fast.

[LittleWatchShop]

31 minutes ago, JohnR725 said:

Being nitpicky to start the day you probably should say balance jewel. Because we tend to end up with lots of flawed jewels in pocket watches

i seldom win these...but, in fairness, I did not show the full plate.  It is not the balance jewel.  I believe it is the third wheel.  See pic.

Thanks for the image...it is now stored with the images of the movement.  You continue to prove that you are the god of watch databases.  Be sure that nobody knows your address...or at least that your books are all stored in a quality gun safe.

 

[JohnR725]

2 minutes ago, LittleWatchShop said:

Be sure that nobody knows your address...or at least that your books are all stored in a quality gun safe

Somewhere on this discussion group I think they were talking about Mark's new shop  which of course was new a century ago? So people were commenting about books so I showed a picture of where my horological books mainly are and I probably just about need a gun safe to fit them all in  but I don't have a gun safe.. So if you could find that image you can see how many horological books I have  other than those that never made it to the shelf yet  bad habit of acquiring books

Then for a lot of key paperwork items they been converted the PDFs.. Is really annoying when paper doesn't last forever  even more annoying if you have a photocopy from way back when one photocopies really sucked and they start fading away  where PDFs tend the last forever. Especially if they're stored across multiple hard drives just in case something fails

 

[LittleWatchShop]

I found the roller table, the staff, and a balance complete on ebay.  Agonizing over the choices.

Here is my balance.

Here is the balance complete.

Here is the roller table, safety roller and jewel.

Here is the staff.

[LittleWatchShop]

I joined NAWCC thinking it would open up a vast database.  I even payed a pretty penny to get Silver level.  So far I have not found the honey pot.  Maybe it is in their physical library...which is not anywhere close to me.

[JohnR725]

1 minute ago, LittleWatchShop said:

I joined NAWCC thinking it would open up a vast database.  I even payed a pretty penny to get Silver level.  So far I have not found the honey pot.  Maybe it is in their physical library...which is not anywhere close to me.

Yes  there located in a nice central location easily get to buy all of us  if we had Star Trek beaming technology.. Even where there located I've heard they're still in the middle of no place because basically that's where the founder originally lived in the middle of no place  but you're a lot closer than I am.

Not to say there aren't resources there is a discussion group except that's open to anybody.. You can ask questions their people will be helpful.. You do have to be careful not to touch on certain subjects because that can end really poorly for you but I'll skip over how I know about that.

They do have some online resource help like you can look up some serial numbers and get the original extract at least for Hamilton. There supposed to have a huge Elgin archive of stuff but  they also claimed there grossly understaffed and that probably will never be scanned ever..

Then of course you have access to the bulletin magazine you go to the index and try to look up things there  has been some interesting articles in the bulletins over the Years