Ping,
In the old days, without CNC milling machines, making extra flat mechanical movements was a challenge. The fine tolerances were not taken on lightly by the watchmakers. Reliability was a problem because the components jammed or the thin plates afforded poor rigidity and thus poor performance.
Still, Piaget persevered in their quest to achieve their Founder's motto: “Faire toujours mieux que nécessaire” (Always do better than necessary). The pursued the thinnest for 'The World is Not Thin Enough'...
That resulted in the mechanical 4P, 9P, and 12P or the quartz 7P movements - all, at one time, the thinnest of their type.
Today, even though modern machines and CAD programs make the job of 'meshing' components together with fine tolerances easier, still not many Manufactures have the temerity or patrimony to pursue “Faire toujours mieux que nécessaire” .........its a philosophy thing!
Regards,
MTF
This message has been edited by MTF on 2010-05-01 09:38:29