Six13
8
Mr. Ohms....
John,
Your response to this op is well reasoned and insightful, as usual. Real world experience has shown us that cross caliber comparisons based on amplitude alone are very difficult indeed. You and I have seen very stable modern movements with relatively low amplitude, ie 270' in 5 positions, and horribly unstable calibres with relatively high amplitudes in the 310 to 325 range. Immediately after servicing a movement, I like to see a small amplitude delta at 0 hour even more than a small rate delta. Large variations in rate are generally easier to sort out than large variations in amplitude. A large variation in amplitude at zero hour is likely to lead to isochronal problems, as overall amplitude drops over time. Or, put differently, large positional variations in amplitude are a bigger problem than large positional variations in rate for the watchmaker. At the risk of putting too fine of a point on the subject, large amplitude variations lead to large rate variations, but high overall amplitude does not neccessarily equal small rate variation.
complicated
By: ei8htohms : September 4th, 2011-09:19
Hello JMan, Discussions of amplitude very often take place between two people with a less than completely thorough understanding of the subject. I once had a US watch industry executive (NOT my current employer) relay to me a story wherein he bragged to h...
Excellent post, John
By: nickd : September 4th, 2011-13:29
Excellent post! As you say, amplitude is more of an indicator of good design and manufacturer, and I wonder if things like balance wheel inertia, "power curve" and reserve de marche would be better indicators of potential performance? If people can obsess...
That's exactly..
By: BDLJ : September 4th, 2011-21:50
...what I'd like to see You'd then be able to interrogate the data by manipulating the scales....but as you wrote, you'd need a fair few samples and a decent amount of background info before you could make any inferences....fascinating, though.
Per watch...?
By: nickd : September 4th, 2011-23:54
I can see the use of this on a per-watch basis, but could you do it as a generalisation for all instances of a movement if it's so sensitive to adjustment, or are some production movements so consistent that it's feasible? nick
Cool
By: nickd : September 5th, 2011-08:33
Hi John, I'd wondered if people used FF transforms for watch analysis. It's used for precision clocks, and I love the idea of long term studies of precision clocks such as various Shortts or the Littlemore showing the earth's natural resonant frequencies ...
lift angle
By: ei8htohms : September 5th, 2011-07:04
Hello nilomis. Lift angle is the angle within which the roller jewel is interacting with the pallet fork, so is the portion of the "swing" of the balance where it is not truly free, but subjected to exterior influences. Lift angle contributes to escapemen...
Mr. Ohms....
By: Six13 : September 5th, 2011-12:46
John, Your response to this op is well reasoned and insightful, as usual. Real world experience has shown us that cross caliber comparisons based on amplitude alone are very difficult indeed. You and I have seen very stable modern movements with relativel...