When analyzing actions I've used both the gauge for measuring key travel versus hammer travel as well as the actual measuring and multiplying out the three separate lever arms. So far, they've been fairly close. However, today I was measuring a MH A and the gauge gave me a AR of 5.2 whereas the measuring of the three arms gave me 5.9. Curious. Assuming I'd measured incorrectly I remeasured several times and got the same result. When using the numbers to calculate via the Stanwood method the predicted balance weight/front weight/strike weight relationships the 5.9 was clearly the more accurate number. At a bit of a loss to explain it so, for the moment, all I can do is report it. David Love www.davidlovepianos.com
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