Center wheel pinion detached from center wheel? How to re-attach? Longines Pocketwatch - ca 1920s

[Dmitry]

Hello, I am a hobbyist and working for sometime now on circa 1920's Longines pocketwatch with 15 jewels movement. I am very determined to bring it back to life and have already overcome a few gotchas, from trivial glass replacement to broken mainspring hook. Just when I have finally put it together after removing 3 broken screws, I was greeted with another surprise: th barrel would just move in either way if I advanced it with a screwdrier ever so gently. Winding up the barrel clicks, but as soon as there is any energy, the barrel just moves around, without hands moving. First I thought that there was a fitment issue. and maybe the barrel did not have proper contact with the pinion of the center wheel, and when I inscpected it closer I found that the pinion just flies around, so if I had an hour hand, I think it would be spinning like in those doomsday movies.

I don't think this was supposed to work like that. Without the pinion and the wheel being coupled, the mainspring cannot hold any energy, so the watch does not run.

Is it even possible to re-solder / re-attach / superglue the pinion and the wheel, so they are fused? If not, how does one go about ordering a new center wheel with pinion for a pocketwatch that is about 100 years old?

Right now I am very tempted to try my battery leads spot welder on that wheel...

Thank you.

[oldhippy]

Could you post some photo of the parts. Normally they are riveted together by means of a punch from a watchmakers staking set.

[KarlvonKoln]

Could it be the safety pinion possibly?  I know you mentioned the mainspring hook was broken off.  If that happened while it was wound more than a little, the safety pinion on the center wheel would release or unscrew, so that the instant release of power from the spring doesn't cause a thermonuclear detonation in there. 

EDIT: I got to thinking: my Longines is a 1919 18.5 calibre and I don't think it has this feature.  I think only my American pocket watches do. Could you maybe post the size/calibre and some pics.  If it happens to be a safety pinion issue, I might be able to help more also.  But I think O.H. is likely correct about this - if the spring cut loose, then the center wheel pinion likely took the hit.  You may want to look through the going train for other damage.  Pics help loads (that, and I can maybe look up the movement in Ranfft's Bidfun archive).

Edited May 31, 2021 by KarlvonKoln
edited for clarity

[Dmitry]

Thank you KarlvonKoln and oldhippy.

Here is a video of the predicament I find myself in.

https://1drv.ms/v/s!ArG5E62RGctxjZs5lRZfnRAz_w3gNg
 

I really hate this wobbling action. I don't have a stake punch set at my disposal, so am looking for other creative ideas on fix it, or alternative approaches of acquiring a similar center wheel.

And here is the bridge plate with the movement details:

https://1drv.ms/u/s!ArG5E62RGctxjZs4JO-uZJNUAJafJg

Thank you in advance for any insights.

[oldhippy]

As you don't have a staking set. You could use loctite 680, it is very good to hold a new pivot that has been made for a wheel in a clock. 

[Dmitry]

... And I broke it. Almost fixed it with an improvised stake punch, but the shaft got bent a bit, so as in those videos Mark mentions, I did not get lucky and the bent shaft just snapped.

I have taken dimension of that thing, any ideas on where to source something like this?

Shoudl I buy one of those steampunk "by the weight" sets and hope that I can score something fitting?

[JohnR725]

23 hours ago, oldhippy said:

As you don't have a staking set. You could use loctite 680, it is very good to hold a new pivot that has been made for a wheel in a clock. 

I was thinking Loctite until I saw the problem. Normally are a lot of times the rivet is the pinioned leaves coming down on to the brass wheel itself but it looks like for whatever reason it's spinning their and it looks loose enough that I don't think Loctite would hold. If it was just pinion had somehow come off the shaft then the Loctite is great.

2 hours ago, Dmitry said:

I have taken dimension of that thing, any ideas on where to source something like this?

Shoudl I buy one of those steampunk "by the weight" sets and hope that I can score something fitting?

it be nice to see a picture of what's left of it? Unfortunately and watch repair we don't have universal parts kind of. So we'll have to see where it's broken I don't suppose you have a watchmaker's lathe?

 

[Dmitry]

JohnR725 - thank you. Any recommendations on which lathe I should get? As I mentioned earlier, this Longines WILL TICK AGAIN!

[oldhippy]

Are you after a watch or clock makers lathe? what is your budget?

[Dmitry]

6 hours ago, oldhippy said:

Are you after a watch or clock makers lathe? what is your budget?

Watchmaking would be the main purpose, anything from pivots to arbors, but I often require some work on larger items. Budget-wize, I would prefer to get something under 1K USD.

[oldhippy]

Have you looked on ebay? If I were you I would look for one that takes 8mm collets. Some like the lathe to be foot controlled (that is what I had) while others prefer direct control and in order to change speed this is done by a way of changing the belts around onto the pulleys.Make sure the bed is in very good condition and the late bed to be true. Would you like me to have a look for you on ebay.  1K USD what is that in english pounds?

[Dmitry]

Longines came back and identified the movement as 18.79. Ranfft does not have it in their database, so I will post the writeup about the movement here in case others require the info. It is one beautiful caliber.

Caliber_18.79.pdf

[KarlvonKoln]

Quite beautiful indeed.  Thank you, Dmitry, for posting this information and adding to our collective knowledge.  I have a Longines 18.5 of my own, and am rather fond of it, and I like learning more about them.

[jdm]

On 6/2/2021 at 4:49 PM, Dmitry said:

Any recommendations on which lathe I should get?

For a start have a read below:

 

[Dmitry]

And the nice 18.79 is now running again!

Scope of changes:

1. Wrong mainspring was installed, the most likely source of why the center wheel got unhinged. Replaced with proper mainspring, which was a bit narrower and less powerful.

2. New center wheel

3. New domed class

4. Snapped screw extraction and replacement on the keyless mechanism

5. A few new screws to replace mismatched in place

6. Complete movement cleaning and service

 

It is now proudle displayed in my collection.

 

One question remains, the porcelain dial is unique, back in the day they were personalized. Mine is personalized with likely owner's name, the same name is engraved on the back of the mainplate. The top layer of porcelain has a crack and a chip at 10, any good sources / tutorials on how to fill/fix those cracks?

Edited June 28, 2021 by Dmitry

[JohnR725]

outstanding that the watches running again

then as far as the dial we need a decent picture

[LittleWatchShop]

On 6/2/2021 at 4:22 PM, Dmitry said:

get something under 1K USD

I just sold a very nice boley on ebay that had excellent runout (less than 15 microns) for $220.  I kinda developed a lathe fetish and started acquiring them...decided I had too many.  I am sure you can find a nice one for this price range.  The one I sold did not have a motor or stand.  You can get a motor for about $100 or buy a sewing machine motor for even less.

 

[watchweasol]

Hi  There is a product by the name of Milliput  which is handy for filling in chips,       https://www.milliput.com/white.html    its an epoxy/resin putty explanation to be had on the site.     cheers

[Dmitry]

Here is a brief close up video of the crack and the chip on the dial. Is this something fixable? I have obtained a few more dials to practice on, just in case.

https://1drv.ms/v/s!ArG5E62RGctxjaQv_pWEmserCYfWTA

[watchweasol]

Hi looking at the chip , a care full application of the Milliputty will do the job     https://www.milliput.com/howto.html    This is a how to script to get the best results.

[Dmitry]

1 hour ago, watchweasol said:

Hi looking at the chip , a care full application of the Milliputty will do the job     https://www.milliput.com/howto.html    This is a how to script to get the best results.

Thank you, what about the ink on the dial? Do I need to sand the dial, apply milliput and then completely recreate the dial with that fansy laser printer decal paper (Mark had a video on a dial restore), or is there a better approach to repair just that part?

Edited June 30, 2021 by Dmitry

[watchweasol]

Hi   Normaly use Indian ink for the marking , Milliputty is available through Amazon or Ebay. Got mine from a Hobbies shop.  If you smooth it out thinly using water as a lubricant as per the words there should be little need for sanding if required use very fine paper with water on a Lollypop stick ( Popsickle) as its just a repair be careful.