thin shanks

[Stephen Birkett]

Jim De Rocher wrote:
> ... transferred back to the hammer by the string.  Not long after
> seeing this film I encountered a Yamaha grand which had one bass
> note appreciably weaker than its neighbors.  Remembering the Kimball
> film, and the dramatic hammer shank flexion, I lightly sanded the
> hammer shank to make it more limber and, presto, the aural strength
> of the sounded note increased to that of its neighbors.  I took ...
>
This is one of the areas I would like to explore with my new computer
modelling project (the one that has no funding yet)...lesson to learn
from early pianos here. When people first started restoring and then
making early pianos it was generally difficult to accept how thin the
hammer shanks were, so the mistake of beefing them up was commonly
made...to the great detriment of the tone. I'm sure many of you will
have heard the xylophone trebles of many so-called early 19th C.
pianos which can be attributed entirely to too-thick hammer shanks and
strike point adjusted too far away from the nut. The treble on a Graf
(c1820s) was typically described as bell-like. I believe this was
achieved primarily through thin shanks. Xylophone trebles are not
characteristic of these early pianos, rather bad restorations or bad
modern `copies'.

 > (For those of you who haven't seen this or a similar film, the
> bending of the shank looks exactly like the bending of a fly fishing
> rod when the angler is casting.)
>
This is a consequence of impedance matching hammer to string.
This film is even of a thick modern shank. Imagine how much the shank
on an 1800 Walter flexes, given that it is almost as thin as a
matchstick.


Stephen Birkett (Fortepianos)
Authentic Reproductions of 18th and 19th Century Pianos
Waterloo, Ontario, Canada
tel: 519-885-2228
fax: 519-763-4686