Knocking keyframe

[Newton Hunt]

Hi, Avory,
      Steinway planes their keybed straight and the keyframe with a curve,
lower in the middle than the ends.
      The keyblock plates warp the frame down so that there is no gap between
the frame and bed and because the frame is under compression a gap will not
occur in the center of the frame.
      The key blocks have a cardboard shim on the bottom which can be peeled
of as needed or restored as needed to keep the frame down on the bed, but just
barely to prevent excessive friction and not to force the center up to cause a
rap.
      The problem is that the height of the block changes from season to
season and continued replacement and removal of block bottom shims is
necessary.
      I have many time wished Steinway had installed screw adjustable block
plate adjusters like Yamaha uses.
      One fix I have used in the past is to drill two holes in the bottom of
the block at each front corner and installed flat head screws that I could
adjust seasonally.
      I had not thought of using shims on top of the key frame pin.  I think
I may use the idea some time.  Beats putting a business card under the
keyframe.

            Newton
            nhunt@rci.rutgers.edu