Cleaning Oddball Jewel Setting From Vulcain Cal. 120 (Msr S2)

[srguitar]

Hi all, my first post because you guys have already asked and answered every other question I've had since the forum started!  Nice work everybody...

 

This is from the updated 60's era shock-protected version of the Vulcain cal. 120 - the MSR S2.  It's from the escape wheel bridge and the whole setting pressed out easily enough with my trusty Seitz tool, but the hole and cap jewels, as you can see, appear to be friction-fit into the setting together and I'm unsure how to safely remove them for cleaning since there is some gummy old dried oil sandwiched between the two without risking cracks.  I fear pushing from the smaller diameter hole jewel side will place excessive pressure on the center of the cap jewel because of the (presumed) convexity of the underside of the hole jewel. In addition, the cap jewel is completely flat on the outside without it's own usual convexity and so appears to be rather thin. I have another identical movement and this one setting is also the same, so I don't think the cap jewel is installed backwards, as I've seen before! 

 

Cap jewel side

 

Hole jewel side

 

There are 3 extremely small notches in the setting around the circumference of the hole jewel, maybe for a special tool? Does this type of setting even have a name? Or should I just see what an acetone bath will do to help and forget about further disassembly?

 

I'm quite curious why this modification to the original design was done. The lower pivot just has a regular old friction-fit hole jewel, so the only advantage I can see to making the top pivot setting like this would be the slightly reduced friction in the dial up position. Does anybody know about these?

 

 

[Geo]

Welcome to posting srguitar.

This is not something that I have seen either. At first glance, it looks like the setting is in two halves and screws together. If this is the case, it may have been designed to come apart with a tool that fits into the three recesses and unscrewed while still mounted in the main plate of the movement.

If it I had a spare movement, I might have been tempted to make a tool and see if it unscrewed, but if not I would do what you suggested and soaked it in acetone for a couple of days before blazing it in my ultrasonic cleaner.

First I would clean it with the appropriate pinion and bridge fitted. I would then remove it the pinion then give the plate and bridge anothe good blast on their own.

I hope someone has had worked with these movement and comes up with a better idea.