RE RE RE Leverage

[Kenneth Sloane]

                      Subject:                              Time:  10:02 AM
  OFFICE MEMO         RE RE RE Leverage                     Date:  8/14/95

-------------Original Posting----------------

Ken wrote:

>And to reply to a comment David Stanwood made to your question. In regard to
>the theoretical, straight-line relationship between the wip action center,
>capstan/wip contact point, and the key fulcrum. I thought David posted some
>conclusions recently about changing the key ratio on a piano. If my memory
>serves me correctly, the conclusions indicated that as the ratio was taken
>closer to 2:1 (at least with this piano), the "straight-line" relationship
>improved, causing a reduction in friction along with the increase in
>leverage.

Ken,

When I speak of changing key/wip ratios by moving the capstan line, I always
assume that the straight line rule is adhered too.  In otherwords, if the
capstan line is moved in towards the balance rail (to increase leverage and
reduce strike weight ratio) the heel thickness (height) will have to be
increased in order to maintain adherence to the straight line rule.

David C. Stanwood

--------------My Reply---------------

Should we assume it was right to begin with? My suspicion is that the
manufacturing procedure at Steinway was designed to have the "straight line
relationship" exist in an action if the key ratio is 2:1. When they slide  the
stack to accomodate strike point (possibly deviating, then, from a 2:1 ratio),
the "straight line relationship" would then be compromised if the ratio did
not turn out to be 2:1.

Ken Sloane, Oberlin Conservatory