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Old 6 April 2023, 06:16 AM   #3816
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32xx movement problem poll and data thread

Originally Posted by HiBoost View Post
I see. 3647 is interesting for sure, and I can see how continuing the trend lines alone might lead to an expected (+5, 290) pairing. But in reality this dataset maxes out at 245 degrees. A better predictor might be to include data you have from a high amplitude watch where I would expect these relationships to stop being linear.
I think you are close but did a wrong assumption: we must NOT extrapolate the trendline in this graph.
I extended the graph shown in #3647 by adding the following timegrapher data sets:

(1) NEW: Before Regulation (highest amplitudes), no PR measurements
(2) NEW: After Regulation (reduced amplitudes), no PR measurements
(3) Before Repair (reduced vertical amplitudes), PR measurements
(4) NEW: After Repair (increased all amplitudes), PR measurements

The isochronism fit for (1) would probably look as I have sketched in the graph below (dotted black line). But I did not measure the PR before/after the regulation, therefore only one data point for (1) and (2).

The dotted vertical (green) line at Xrate = 0 s/d indicates perfect isochronism, that means the average amplitude decreases but the average rate remains constant.

Originally Posted by HiBoost View Post
Isochronism aside, I don't believe amplitude will continue to increase beyond its full-wind peak based on a simple regulation. Consider the Sea Dweller data you have in that graph. We drop from 245 degrees to 160 degrees and the timing drops about 5 s/d. But surely we would not expect the amplitude to go from 245 up to 330 just by regulating up 5 s/d.
Agreed, explained above, one must NOT extrapolate the fit (trendline) of data set (3)
Originally Posted by HiBoost View Post
Or to put it another way... I think of isochronism as the movement's ability to resist rate changes as the amplitude drops from its full-wind, full-strength levels. But this does not imply rate is the primary input driving the amplitude.
Agreed, isochronism means that the rate remains stable with changing (decreasing) amplitudes. Sure, that rate is not the primary input increasing the amplitude, but I say: if a watchmaker trims the 32xx movement to obtain highest amplitudes, without looking at the rates, then high rates will be the result. That is the aim of my proposed experiment.
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