Steinway key humping

[Paul Chick (Earthlink)]

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On
Behalf Of Carl Meyer
Sent: Sunday, October 19, 2003 7:58 PM
To: pianotech@ptg.org
Subject: Steinway key humping


I've commented on this before, but some may not have noticed or disagree
with me.

Since I am the self appointed key leveling guru, I need to reiterate that I
believe the idea of the 1/16 hump in the key leveling of S&S has been
misconstrued.  Setting a hump in the keyboard for the purpose of
compensating for the  sagging due to the excessive playing of the center is
just urban legend.

I recall when I first heard that, I was impressed with that concept.  I have
been now convinced that to misadjust to compensate for wear is not a logical
engineering decision.

An S&S rep told me that the reason for humping the key leveling is to
compensate for the fact that they shape the key bed for a level of crown of
about 1/16 inch during manufacturing.  The key level then should follow the
curvature of the key bed.  This requires the key frame to be clamped by the
cheek blocks for the purpose of having better contact due to the curvature
of the key frame.  I was then told that it was necessary to level (sic) the
keys in the piano since that would be the only way it would be accurate.

I still hold to my concept that if you clamp the action (key frame to a flat
table) and LEVEL the keys, when you reinstall the action the hump will
automatically the same as the key bed.  Isn't that what they want?  Any
additional leveling to what ever shape you want or touch up can be done
after the action is in the piano.  You may drive yourself to utter
frustration or terminal if you like.
Carl Meyer Ptg assoc
Santa Clara, Ca.

Carl
Your explanation does make some sense but, since the front rail is the one
being clamped, is the balance rail(middle rail) going to bend as much to
take the desired hump?  The front rail is not used to level the keys.  I use
to put the "hump" in the keys for Steinways.  I no longer do it, and no one
has ever noticed.

Paul C