My experience is that a 1 mm move of the knuckle changes the overall ratio by about .4. That would be consistent with your findings. David Love ----- Original Message ----- From: "Richard Brekne" <Richard.Brekne@grieg.uib.no> To: "PTG" <pianotech@ptg.org> Sent: January 05, 2003 2:47 PM Subject: Ratio Question Hi guys and gals. Got to looking at another action today and found some figures I'd like to share with you. This one has a Key Ratio of 0.5, a whippen ratio of 1,67, and hammershank ratio of 7.65, which comes out to a 6.4 (roughly) ratio. Hammers are quite light by my standards, and are scattered in the Stanwood low zone, and there is little front weight mass. All adds up to a light playing light sounding instrument. Mushed out hammers combined with this makes for an interesting sound :) Anyways... the whippen and shank numbers are 97/58 = 1,67 and 130/17 = 7,65. If I moved the knuckle out 1 millimeter then I would get the following... 96/58 = 1.655 and 130/18 = 7.22 which combined with the KR of 0.5 gives a new total action ratio of just under 6.0. That seems like a whole lot for just 1 mm move on the knuckle.... and I am looking for good explanations here. I have read several places that whippens usually have a ratio closer to 1.5 then this action has. Perhaps this high ratio combined with the low key ratio is the cause here ? Or what... ?... Scratchin my head late Sunday nite... grin. RicB -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
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