Just published a family tree on my blog for the Jet automatics made by Citizen in the early to mid 1960s. Find it here:http://sweep-hand.org/


Stephen

Why is the hand winder thicker than the auto?

And why are there date and no-date variants of identical thickness?

hope this answers your question Chascomm:

031 / 032 / 034 - all versions are plain dialed automatics (no date / day), 4.70mm thick

112 / 113 / 115 - all versions are automatics with date only, 5.00mm thick

116 / 117 - all versions are automatics with date only, and 'easy change' quickset mechanism, 5.34mm thick

4000 - all versions are handwinders with date and day, 5.15mm

410 / 411 / 412 / 413 - all versions are automatics with date and day, 6.39mm thick (Easy Change models - 411's same thickness)


Although the 4000/4100 movement was produced later it was a thicker design than the 031/2 & 11xx movements.

There's a summary of the Jets which shows the no date / day / date variations here:http://sweep-hand.org/the-jet-automatic/


Stephen

So as I understand it the greater the number of features in the calendar mechanism, the thicker the calendar module.  Hence the hand-winding day/date being thicker than some of the automatics.

I've added three 'exploded' views of the movement to my blog page on the Jet Automatics:http://sweep-hand.org/the-jet-automatic/


Stephen