Hello again, I'm wondering if the concept of accelerated action has less to do with the downstroke (less inertia to overcome on a high velocity strike) than with the return (with the weight(s) closer to the balance pin they are less effective counterbalancing the stack mass- potentially a quicker return). I guess it has a perceived overall benefit on both sides of the keystroke? Rich On Thursday, May 1, 2003, at 01:14 PM, Classic Touch Ent wrote: > Greetings Richard and Don and all interested, > > While the example given states a relationship regarding inertia and > the effect of weight a given distance from the 'fulcrum', it seems > somewhat removed from my real world experience. > How many pianos have weights placed one cm from the fulcrum? See > http://www.stanwoodpiano.com/Pa100088web.jpg . (I.m guessing the lead > closest to the balance pin (fulcrum) is 7- 10 cm away.) > That aside, at any given distance, how much assistance does a weight > or weights give the pianists finger moving the 'stack mass' (which is > say 11 cm on the other side of the fulcrum)? and at what velocity? and > finally at the location of the pianists on the key lever? Doesn't the > distance of the pianists finger from the fulcrum mitigate the > effectiveness of weights either fore or aft of the point of finger > contact (and at differing rates of effectiveness for differing > velocities)? Isn't it interesting that the pianists finger position is > (by necessity or choice) variable? Richard Brekne, the name of your > pharmicist/drug store (do they deliver to the US) please. > > Best, Rich Olmsted > > On Wednesday, April 30, 2003, at 08:33 PM, Don wrote: > >> Hi Richard, >> >> The inertia goes up by the *square* of the distance from the >> fulcrum--so >> yes three weights would likely have less inertia than *one* farther >> from it. >> >> Run the numbers >> >> 30 grams x 1 cm from fulcrum = 30 > How many pianos have weights placed one cm from the fulcrum? Of any of > my grand pianos the closest weight is 10 cm from the balance pin. Also > See http://www.stanwoodpiano.com/Pa100088web.jpg . I.m guessing the > lead closest to the balance pin (fulcrum) is 7- 10 cm away. > From what I have observed the 30 grams nearer the fulcrum might more > likely be (3) 10 gram weights spaced over a distance, say 7- 12 from > the balance pin (not in the same location & each having a different > effect). >> >> 10 grams x 3 cm from fulcrum = 90 >> >> If I'm wrong please let me know *grin*. >> >> Regards, >> Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T. >> >> mailto:pianotuna@accesscomm.ca >> http://us.geocities.com/drpt1948/ >> >> 3004 Grant Rd. >> REGINA, SK >> S4S 5G7 >> 306-352-3620 or 1-888-29t-uner >> _______________________________________________ >> pianotech list info: https://www.moypiano.com/resources/#archives >> > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives >
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