Piano keys are balanced

Carl writes;
>Piano keys are balanced. It should require almost no pressure to move

>them.

It should require between 46 and 56 grams of downforce,depending on the
piano and location on the scale. key to key differences should be less than a
gram. However, that is only part of the equation. Properly regulated
actions have the proper upweight, too, and the relationship of up to
downweight is the determination of "touch".
There is an optimum amount of friction involved, as well as the all
important ratios that exist within the action. You have a folded beam
mechanism that takes three opposing arcs into account to produce a very
particular resistance. The use of lead weights in the keys is universal, to
get the balance right, however, a poor set of ratios, or overly large hammers,
will call for so much lead that the inertial resistance to fast play makes the
piano feel like a truck if you play it hard!

Carl again:

>The majority of pianos are poorly regulated.
I agree 1000%

>It isn't too difficult, and

>you can do it yourself with $20 worth of tools
I disagree 1000%. Unless this is in the same vein as throwing a clay
pot, where it is easily seen how simple it is to do (:)}}.
Perhaps a gross adjustment of the parts is possible by the novice, (though
in my experience, the ensuing breakage cost them more than they expected), but
fine regulation, of the sort expected by professional pianist, is a long time
learned.

Carl again:
> A good grand action resets the instant the hammer leaves the

>jack.
Hmm, not quite. The hammer goes into check, but the key must still be
allowed to rise a certain amount for the jact to reset, (at least partially)
under the knuckle.
The major factor in repetition speed of a grand is the height at which the
hammer checks under the string, for this determines how much upward key travel
is necessary for the jack to go back.
There is a downside to this, in that the higher the hammer checks, the
less force the pianist can apply to the string. Ya just can't get much energy
going in 1/4" of hammer travel! There is a particular distance that is
optimum. Normal checking height is halfway to the string from rest, but the
faster classical pieces benefit from a closer setting. Making springs
stronger is a mistake, as it interferes with the most delicate pianissimo
control provides no faster key return than a moderate spring.

>Stride was developed on uprights, because it took that long for the

>keys to pop back up.
A properly regulated upright will repeat faster than any stride I ever
heard. But an upright is not as fast as a grand, and I don't think ever will
be.

Regards,
Ed Foote
Precision Piano Works
Nashville, Tn.
http://www.uk-piano.org/edfoote/index.html