Landeron 248 disassembly videos

[GeorgeClarkson]

Since I was working on the Landeron 48 with wrong dial, from which I used the case and a Landeron 151 and correct dial to make a new watch, I saw this Landeron 248 sitting in the drawer at my desk and devided to finally tackle the issue it had: a slipping mainspring.

I documented the disassembly of the movement vith 3 videos, the first of which is here below:

Hope you enjoy

 

[GeorgeClarkson]

The second part of the video is finally ready:

Enjoy...

The third and final part will be uploaded in a few days.

Edited July 21, 2016 by GeorgeClarkson

[GeorgeClarkson]

Third and last part of the dissassembly videos:

 

Enjoy.

[bobm12]

Watching them now! I don't know how I could miss all these posts! Ok, I know, I've been away! I can't have the cake and eat it too!

Cheers,

Bob

[GeorgeClarkson]

No worries Bob, I hope you enjoy the videos!

[bobm12]

I did! Thank you for posting them!

Cheers,

Bob

[matabog]

So why was the MS slipping? 

 

could you post a link to the end of the story?

[GeorgeClarkson]

On 16.3.2017 at 2:05 AM, matabog said:

So why was the MS slipping? 

 

could you post a link to the end of the story?

Sorry for late reply, life got in the way... Yes the main spring was slipping so I need to source another MS.  

[jdm]

Yes the main spring was slipping so I need to source another MS.  

Braking lubricant is not good enough? Or the barell wall surface is too smooth.

[matabog]

MS slipping - was the problem the end piece of the MS? The one that catches the groove in the MS barrel?

[jdm]

Oh it's a manual winding watch? Sorry. Anyway a new MS is always good.

[GeorgeClarkson]

On 3.4.2017 at 8:14 AM, matabog said:

MS slipping - was the problem the end piece of the MS? The one that catches the groove in the MS barrel?

Actually no,the issue is that the mainspring slips on the arbor, so i am not so sure the new mainspring will suffice, probably will need to replace the entire barrel assembly including the mainspring... At the moment I do not have time to work on this movement unfortunately, so it will have to wait.

[matabog]

It might not be a barrel arbor/MS problem. 

Another scenario could happen: it is very hard to see because the crown wheel is beneath the wheel train bridge. 

Normally, when you turn the crown, you actually turn the sliding pinion (clutch wheel) which turns the winding pinion (under the force of the yoke and yoke spring); then the winding pinion turns the crown wheel, which turns the ratchet wheel, which finally turns the barrel arbor 
Because of poor oiling or wear, two things might go wrong: the sliding pinion might disengage the winding pinion (wear on the Breguet teeth), or the winding pinion might disengage the crown wheel (the winding stem might have some wear on it and the winding pinion might be allowed to seat at an angle lower then 90 degrees). There would be a sudden MS discharge that you would see on the crown wheel (aprox 30 degrees in the opposite direction if you drew a dot on it, for example).

[GeorgeClarkson]

Great explanation but not my case. I installed a good barrel assembly and it didn't slip so definitively the issue is with the barrel/arbor