---------------------- multipart/alternative attachment John, I don't know how much key leads really affect moi in the total picture of things, since the leads serve at least two purposes; one, as a "counter weight" to what weight there is bearing down at the capstan, and two, as moi regulator of sorts. But the leads seems to affect the total moi more than it appears. Doesnt the leverage system of the action reduce the hammer's effect on moi? So if you take the moi of the hammer /shank assembly separately (taking it out of the chain of leverages), will it not seem as though it has a greater effect than it really does? [link redacted at request of site owner - Jul 25, 2015] Vince, I am not sure what your customer is relating to but the evidence seams to be that adding leads to the keys does not raise the total MOI of the action very much. This is because the increase in angular motion from the key to the hammer increases the Moi of the hammer much more than than than the 5/1 leverage we usual think about. I figured the MOI for the three action parts of a typical note. The hammer was 8 gms and there were three leads in the key. The front arm of the key was 25cm and action leverage was 5.3/1 with a BW of 35gms. Here are the number for the MOI as adjusted for reflected MOI: Key MOI = 10,307 gmcm^2 Wippen MOI = 3149 gmcm*2 Hammer and shank MOI = 165,528 gmcm*2 There may be many virtues for keeping leads out of the keys but I can't see how it makes very much difference to the perceived weight of the action. The difference in MOI due to the leads you mentioned seam insignificant to the total picture. John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor [link redacted at request of site owner - Jul 25, 2015] _______________________________________________ caut list info: https://www.moypiano.com/resources/#archives Vince Mrykalo University of Utah --------------------------------- Do you Yahoo!? Yahoo! Photos - Get your photo on the big screen in Times Square ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/cf/26/c0/45/attachment.htm ---------------------- multipart/alternative attachment--
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