A Faulty Pellaton Winding System In An Iwc 8541S Movement.

[cdjswiss]

After a thorough clean this IWC 8541S movement was working well except for the Pellaton automatic winding system. You can see in the photo (taken before the clean and oil) that the two hooks are not engaging the winding wheel.

 

 

To remedy this fault I tried several different cleaning methods including ultrasonic in a bath of penetrating oil. This freed-up the long hook, but the short one although it could be pushed around would not spring out into the winding position. You will see in this picture of the Pellaton system (Michael Friedberg, IWC forum) that there is very little effort exerted by the spring onto the short hook.

 

The two plates of the Pellaton system are screwed together, but nothing would budge these small screws. About to bin the piece and search for a replacemet; in desperation I inserted a 0.5 mm screwdriver blade between the plates and gave it a twist. Out popped the short hook. Then with more cleaning and another screwdriver twist for good measure, after re-assembly, I had a working automatic movement once more.
 

Edited July 18, 2015 by cdjswiss

[Geo]

Good result Colin, that's not a system I'm familiar with. I'm assuming you gave up on removing the screws and just gave it a bit of lubrication as an assembly.

[Lawson]

Good stuff Colin!

 

Did you try putting the parts in a container will very light grade oil and then placing the container in an ultrasonic bath with the heat turn up full?

This is one method to help free up those nasty seized small screws we all hate.

[cdjswiss]

Yes, Geo and Lawson, after cooking the Pellaton in a small jar filled with penetrating oil, itself placed in a powerful ultrasonic bath for 4 minutes, I gave up on the small screws. I hate damaged screw heads. But the US bath did free up the large hook and prising open the two plates just a few microns with the screwdriver loosened the small hook sufficiently for the second bath to clean up whatever gunge was holding it against the pressure from the wire spring. I wound up with a working Pellaton that had undamaged screw heads. (no smiley - I dislike them)

[Geo]

The auto mechanism looks to be a very simple system compared to others. Is the split in part number twenty forming an anti-shock system for the auro mechanism?

[cdjswiss]

A good question, Geo, you must be correct in assuming that it is an anti-shock feature. I suppose that it is mentioned in the patent application, but I have not looked for that.

 

Here is an article describing the history of the Pellaton system:

http://people.timezone.com/library/itsabouttime/itsabout0002

And this one on its application to the Cal 85xx series by Michael Friedberg:

http://www.iwcforum.com/Articles/Calibre85Family/Text.html

[cdjswiss]

Proof of the pudding:       Here is the Cal 8541 in the winder keeping excellent time and running on automatic.

 

[Geo]

Another unique piece of horology and great job Colin. Also many thanks for posting the links above, they made interesting reading.