S37 WINDING PROBLEM AND BROKEN SCREW (CORRECTLY INSERTED)

[flandecoco]

Hi everyone. This is my first post. I’ve just started with the hobby and have begun experimenting with some movements. I disassembled a 6139 chronograph, which was a terrible decision...  Following advice from some forum members, I acquired a clone ETA 6497 and started working on it. Everything was going well until I inserted the crown wheels and started winding the watch. The crown turned with great resistance until, suddenly, the crown wheel screw broke. The screw was correctly inserted (reverse thread). Do you know what might have happened? I suspect there may be an issue with the barrel or mainspring, but I think it was properly inserted...

[AndyGSi]

34 minutes ago, flandecoco said:

Hi everyone. This is my first post. I’ve just started with the hobby and have begun experimenting with some movements. I disassembled a 6139 chronograph, which was a terrible decision...  Following advice from some forum members, I acquired a clone ETA 6497 and started working on it. Everything was going well until I inserted the crown wheels and started winding the watch. The crown turned with great resistance until, suddenly, the crown wheel screw broke. The screw was correctly inserted (reverse thread). Do you know what might have happened? I suspect there may be an issue with the barrel or mainspring, but I think it was properly inserted...

Welcome to the forum

With all posts photos will help.

As a note going forwards, if you feel any resistance then stop, don't try and force anything.

[flandecoco]

I've learned the hard way about not forcing the caliber...

Unfortunately, I don't have any pictures. I'll take some and send them as soon as possible.

Thanks for the quick response!!!

[praezis]

2 hours ago, flandecoco said:

The crown turned with great resistance until, suddenly, the crown wheel screw broke

Sounds like anywhere between winding stem and barrel, teeth didn‘t mesh but sat above each other. You should test correct meshing in that range befor applying force. I think you know now .

Frank

Edited November 11, 2024 by praezis

[flandecoco]

I've checked the movement and now I know what happened... The crown and ratchet wheels were upside down, as you can see in the first pic, which I should have guessed from the lack of their sunray pattern… (dumb and dumber). The wheels weren’t meshing properly, and the torque applied broke the crown wheel's screw. Fortunately, I had a broken screw extractor on hand (a reminder of my bad experiences with the 6139 caliber). Not only did I break this screw, but I also broke both dial's pins. A total success!!! Thank you very much.

[nevenbekriev]

1 hour ago, flandecoco said:

I've checked the movement and now I know what happened... The crown and ratchet wheels were upside down, as you can see in the first pic, which I should have guessed from the lack of their sunray pattern… (dumb and dumber). The wheels weren’t meshing properly, and the torque applied broke the crown wheel's screw. Fortunately, I had a broken screw extractor on hand (a reminder of my bad experiences with the 6139 caliber). Not only did I break this screw, but I also broke both dial's pins. A total success!!! Thank you very much.

 

 

 

Well, one will learn from His mistakes only if correctly understands what has happened. I am afraid You didn't quite understand...

To break the screw, it is enough to put the crown wheel upside down and even not to put ratchet wheel in place. Turning the crown will break the screw then. See, there is recess in the center of the wheel, where the screw head goes. When the wheel is put correctly, the screw head will sink in the recess and will rest on the top of the post when tightened . The wheel will be free to turn with no resistance.

If the wheel is upside down, the screw will tighten directly on the wheel, as there is no recess. The wheel will be not free. Turning the wheel in winding direction will turn the screw head too, thus tightening the screw more and more. This will result as breaking the screw or the thread in the post...

[flandecoco]

35 minutes ago, nevenbekriev said:

Well, one will learn from His mistakes only if correctly understands what has happened. I am afraid You didn't quite understand...

To break the screw, it is enough to put the crown wheel upside down and even not to put ratchet wheel in place. Turning the crown will break the screw then. See, there is recess in the center of the wheel, where the screw head goes. When the wheel is put correctly, the screw head will sink in the recess and will rest on the top of the post when tightened . The wheel will be free to turn with no resistance.

If the wheel is upside down, the screw will tighten directly on the wheel, as there is no recess. The wheel will be not free. Turning the wheel in winding direction will turn the screw head too, thus tightening the screw more and more. This will result as breaking the screw or the thread in the post...

Awesome!!! Thanks a lot!!!