[pianotech] action ratio

[Ron Nossaman]

On 8/29/2012 8:47 AM, David Love wrote:
> Not to beat a dead horse but FWIW one thing I do notice, with my action
> model anyway, is that the jack movement (and key movement for that
> matter) from the point of jack tender contact with the let-off button is
> about 2.5 – 3 mm which, on my model, translates to about .040” key
> travel after the point of escapement.  So if “aftertouch”, at least in
> this formula, is based on travel after contact with the let-off button
> when the jack starts to move horizontally rather than vertically, then
> the output of my design chart seems consistent with real world results.

Good observation. I'd be curious to eventually see at least a small 
compilation of comparisons between feel adjust - measure, and measure - 
feel judge to see how definable our individual "windage" actually is.
Ron N