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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoPlainText>I use the measure points because they make the most sense to me—I've no idea how they correlate to those used by others. The most wear on a key takes place about 20 mm back from the front of the key so I assume that is where most pianists strike the keys most of the time. So that is where I start my measure. The next lever goes from the balance point to the center of the capstan. Then from there to the wippen flange center. Then to the tip of the jack where the jack contacts the knuckle. (Yes, I know the force goes first to the jack center but if you study the action model....) And then from the knuckle center to the hammershank center and from there to the tip of the hammer. Anyway, those are the points I use.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>The longer the lever the less absolute accuracy matters. I usually try for the nearest half-mm. Sometimes I settle for the nearest mm.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>It's easier when you are designing an action and key set—you can take it out to 14 decimals on the computer screen if you want. Not that that makes any real difference in the real world. And you don’t have to go through any contortions to get your measurements.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>ddf<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Delwin D Fandrich<o:p></o:p></p><p class=MsoPlainText>Piano Design & Fabrication<o:p></o:p></p><p class=MsoPlainText>6939 Foothill Court SW, Olympia, Washington 98512 USA<o:p></o:p></p><p class=MsoPlainText>Phone 360.515.0119 — Cell 360.388.6525<o:p></o:p></p><p class=MsoPlainText>del@fandrichpiano.com — ddfandrich@gmail.com<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<br>From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Brown, David<br>Sent: Thursday, September 20, 2012 11:48 AM<br>To: pianotech@ptg.org<br>Subject: [pianotech] Action Ratio measuring</p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Del, David and all-<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Huge thanks for the completeness of these explanations and examples. Del, the pdf was very clear. I am on a Mac, so bins and the like come out wacky. I do notice from your example that this is yet a third way to measure key in, from balance point to front rail pin. How fussy are these in practice? Do the relationships remain constant? It would not seem so. +/- a mm? More ? Less? Thanks for all for taking daytime for this. It will take a while to digest.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Best-<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>David<o:p></o:p></p></div></body></html>