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Canuck
·Most manual watches made in Switzerland with 17 jewels were considered a safe bet reflecting quality and durability..
Earlier models with 15 jewels lacked the shock protection and the center wheel did not have a jewel pivot where the bushing would wear prematurely causing side shake. The addition of the extra jewel minimized the premature wearing. One would of course always service their movements to avoid any form of oversight
Self winding watches (automatic) with 21 jewels or more were considered to also reflect the same safe bet..
There are also 17 jewel automatics that one would wonder whether they are less superior to the manual version containing the same number of jewels which obviously would have required more jewels to justify the automatic assembly Especially reverser wheels was always an issue if any servicing was overlooked.
Most of the Felsa movements that I have come across in automatics have a rotor jewel which in my opinion is a classier setup than the Rolex naked axle sleeve and Omega rotor post on rivets. In this case the rotor jewel added in that area makes one wonder if adding more jewels to a movement makes it better? Begs the question is it myth in some ways and fact in other ways!!
The movement shown in this post has what might appear to be a “perimeter rotor”. That is, the component stamped 100 jewel is a 360° ring affixed to the rotor. Some watches of this design utilize an internal ring gear which actuates the winding gears in the automatic winding. Some watches with this type of auto wind system have the rotor and attached ring running in jewelled bearings. In the case of the subject Waltham 100 shown in the picture, there are many cap jewels installed in the rotor and the ring, those jewels being barely visible around the outer perimeter of the ring. Not truly a perimeter rotor, with the self winding mechanism operating just as it does on a standard self winder. The movement pictured is pivoted in the centre of the rotor on a standard rotor post. The true perimeter rotor doesn’t have that centre rotor post, the rotor operating on a jewelled race around the perimeter. The jewels in the ring serve no function.
