Grand action geometry

[PianoGuru@aol.com]

In a message dated 95-06-10 17:29:33 EDT, Richard West wrote:

>Are all 9' concert grand actions created equal when looked at from a
>geometric perspective?  In other words, can there be many geometric
>variations to get the most power, repetition, and control out of an action
given
>a 9' length and less concern about the economics of building the
>"ideal" piano than a smaller grand.  Secondly, if there is an ideal,
>can we in the field really recognize that any one particular action is
>not up to par.

Your reference to manufacturers' rep's, my recent presence on the list, and
its ensuing controversy, compel me to comment on your question.  I do not
claim to have an instant answer for all questions, or any question, for that
matter.  Your questions do, however, sparky my interest.  The following is my
initial reaction to the issue raised; there may be more later, pending
further investigation and response to  the topic.

All Baldwin (and new Chickering) grand actions are essentially the same,
except the SF-10 & SD-10 which have Renner actions.  The Baldwin grand action
is basically the Clemsen action, developed by Pratt-Read.  Frankly, I believe
that our action plant could build an action as good, or better than the
Renner action for our concert grands.  The primary reason we continue to
install Renner actions in the concert grands is for the benefit of the Renner
name.  The point is that the "ideal" grand action is no different
geometrically for a small grand than for a concert grand, for a Baldwin than
for any other manufacturer.

Please bear in mind that I am referring to the action as the
"super-structure" of the action-keyboard assembly.  The benefits of the
concert grand are the availbility of space for a string scale that approaches
an ideal string length, soundboard area, and key length.  The significant
differences between a concert grand action and smaller grands lie in the key
ratio/length, not in the super-structure geometry.

In manufacturing, we can reconsider the position of the balance rail, and
thereby the key ratio.  In the field, this is pretty much out of your
control, unless you wish to plug and re-bore the balance pin mortises.  It is
conceivable that field tech's could plug and re-bore the capstans, or
reposition the super-structure fore-and-aft, or up-and-down over the
capstans.  I am not suggesting that this should be done, but that these are
realistic avenues available to you for altering the action geometry, if such
alteration is warranted.

Bottomline: Stick to the manufacturers' specifications for action
(super-structure) geometry.  If this does not yeild the desired results,
consider changes to the key ratios (i.e. capstan position relative to the
super-structure), the reason being that this is the only parameter that
distinguishes a concert grand from smaller grands, and the most practical for
after-market consideration.

Frank Emerson
Baldwin R & D