PeterCDE
10167
Thank you!
Hi Mark,
that?s a short overview only; i think there?s a lot more that can be said and it will be a rather long page: between mid 1950?s and early 1970?s, GP made a new movement/iteration at least once every year. It was a very interesting time and there is a rather big variety of Gyromatics! For the GP 31/32, the number of iterations with sometimes tiny changes count more than a dozen.
And that was the reason to end the initial overview in 1962, when the first "thin" automatics with GP 31/32 came out. Subsequently, the fast-beat movements came (1965), followed by the 2nd generation of fast beaters (1969/1970), movements with different ebauches by AS and FHF in 1970?s up to the Longines 990 double-barrel and the Universal Geneve 2-66 microrotor in mid/late 1970?s.
So there?s quite some input and a somewhat comprehensive overview will need a bit more space and time. But that will come in 2005 (as far as the book by Chaille doesn?t cover it).
Ok, for the fast beat movements:
The first iteration was introduced about 1965; GP 32.7 was a variation of GP 32 and the outer appearance is very likely. It was followed by GP 32A, the movement found in early ChronometerHF pieces of the 2nd run and GP 42, the variant with improved power reserve.
Here?s a 1965 GP 31.19 (21.600 A/h conventional beat rate) and a 1970 GP 42 (36.000 A/h fast beat); you may see they are very likely, but different in terms of the escapement (smaller balance for the GP 42) and regulation (GP patented micro-screw fine regulation for the GP 42):
Actually it doesn?t look impressive.
But the timing results do; it is certainly among the most accurate serial production movements ever made.
These do deserve being covered a bit more detailed and they are subject of ongoing research (with results to be shared later).
Warm regards,
Peter
