A client sent in this rare beast after we agreed I would not be held accountable if anything was to go wrong;) The watch is running but the second second recorder does not reset to zero position.
Watch is preforming okay, but we decide to go for a full service.
Nice looking construction or an invitation to trouble?
The second second recorder is placed in the centre of the first second recorder and is held in place by a brake when not engaged.
I start by removing the hands.
I find it easier to remove some of the components before taking the movement out of the case.
Here you can see the Column wheel that engages and disengages the second recorder wheel.
The second second recorder is engaged with a lever that is linked to a pusher in the centre of the crown.
One part at a time I get closer to the base movement.
I now take the movement out of the case and start on the dial side.
Here I lift the moon-face disk out of position.
There is a date wheel gear underneath the moon-face disk.
After removing the moon-face and date mechanism I start taking apart the hour recorder mechanism.
After removing the hour recorder I start on the setting/winding mechanism.
The intermediate second recorder wheel is so tight on the third wheel pinion I can’t get it off. So I will clean them together.
Everything gets cleaned and is ready to be put back together.
Barrel gets new mainspring.
I see that the balance moves freely after being put back together.
I put the running gear back together.
Hour recorder, winding/setting mechanism back in the movement.
I start putting in the date and moon-face mechanism.
I place the movement in the case for easier assembly and testing of the numerous functions.
Dial side done.
I adjust the beat error.
Base movement is running. (I fit the bezel and the old crystal when working on the watch like this)
Watch preforming well.
Chronograph layer coming together.
Movement back together and running.