Tips from a pianist!

[Newton Hunt]

Hello, Anton,
      And welcome to pianotech.
      Your input is most valuable for those of us who do not play the piano,
just work on them.
      Your points are well taken and I would like to make a few comments.
      Sharp keys should be leveled 12mm above the white keys.  12.5mm at the
extreme maximum.  If yur dip is at 10mm then when the sharp is fully depressed
it will remain 2mm above the white keys.  This is very simeple and effective.
      Key balance holes need to be free but without any fore and aft
movement.  Using a capstan wrench to enlarge the hole is a poor approach in
that the hole is larger at the very bottom than slightly above.  The conical
shape MUST be from top to bottom.  There is a tool make for this easing which
can be purchased from most supply houses.  Please get the one with a continuous
taper.  It is easier to control.  It is inserted through the top of the key and
then rotated until the fit is as needed.  The tool is flattened on two sides to
allow this approach.
      Key pins need to be polished and lubricated and the key bushings need
to be lubricated.  I like to polish my pins with FLITZ, available from Pianotek
and a dry Teflon lubricant on pins and bushings.  I have found that key
bushings last three to five times longer with this approach than they will with
out.
      The hammer strike points must be level when they are contacting the
strings.  By using the key slip to raise the hammers to that level they can be
shoe shined with fine sandpaper until perfectly level.  Place a strip of
bushing cloth between the knuckles and the wippen tops.  When pushing down a
key the let-off is now so high that they hammers block on the strings and the
strings can then be lifted and leveled, tuned, lifted, tuned, etc. until
perfect.
      Rep lever springs need to be strong enough to lift a hammer firmly, but
not so tight that they bounce when they reach the end of their travel.  If
anything I would error on the side of weak instead of strong.  There is a
considerable toleranced range here.  Even is most important.
      Well, enough of my soap box.
      Anton, you should download the digests, print them and take them with
you on the road to read at those times when one is bored or moving around.
            Newton
            nhunt@rci.rutgers.edu