key click

[Newton Hunt]

Dear Ed,

Several possibilities come to mind.  Analyzing a problem is a process of
elimination by isolating each section of the action, one at a time.  It
is quite possible the noise is coming from two or three places, all at
once, but isolating each area individually will show where it or they
are.

The four section are the key, the wippen, the hammer and the damper.

First the key.  Carefully look at each part of the key, the wood itself,
the key top, the key button, the bushings, the mortises, the front,
center and back rails and their respective felts, the capstan, or what
passes for the same like rubber grommets, forks or sockets and key
weights.  On grand pianos look further at the backchecks, keyend felts
and additional pieces of wood glued to the key.  Carefully check and
evaluate each element.

The wippen section is more difficult to check, but check the sticker
(abstract), the backchecks, the bridle wire, the bridle strap, the jack,
it's pinning and glued flanges, the jack spring, the pinning of the
wippen flange and if the wippen screw is loose, a common occurrence in
older pianos.  Again isolate each section and check for undesirable
qualities like too hard felt or too hard bridle strap tabs, loose wires
or wires hitting each other, etc.

The hammer section has hammer heads with felt, glue and staples, shank,
leather, flange and screw, spring seat, backstop with two glue joints,
leather and bridle strap, check pinning and it's passing it's neighbors,
return spring and seat.  Check also the hammer rest rail, felt, stop
blocks, felt shims, pivot hooks and bushings, the pedal levers and reach
usually dowels).

The damper section comprises the hammer spring rail with damper stop
felt, the damper felts and blocks, damper wires, lever with spring seat
felt and lift felt, flange with it's pinning and spring.  Also included
are the spoons of the wippens, the lift rod, it's hooks, hangers and
bushings, reach, lever and pedal with pivots.

What you did when you placed the felt under the keys is change a lot of
things that include the key elevation, rest position, the wippens were
raised and the hammer shanks are off their rest thereby changing the
relationships of all the parts.

Make up a chart of these elements before going back to the piano.
Carefully checking ALL the elements, even if you think you have isolated
the problem early on.  By using such an approach for any problem makes
finding it simple.

            Newton