Even balance weight or even something else, that's thequestion.

[Phillip Ford]

>I think it is a slight misstatement to say the uniform balance weights
>produce uniform feel............



>As for Richard Brekne's question, did I have something in mind when I
>suggested using inertia, or a dynamic model.  I can't say that I have a
>specific idea.  I don't really know how to handle the inertia question in 
a
>quantifiable way--not yet anyway.  There are those who are working on the
>project, though, and it will be interesting to see what comes of it.

A complicated model might be informative.  However, something much simpler might also prove useful.  Calculating the inertia of the keys would not be that difficult.  They're essentially rectangular sections.  An engineering handbook would provide the formulas.  As a rough cut I would think that a measurement at the whippen heel of the whippen, hammer, and shank weight with them installed on the stack could be assumed to be a weight on the key at the capstan location.  The inertia of this weight could then be 
calculated.  It's not difficult to determine the increase in inertia of the key from adding leads.  So, if you had an inertia curve that you were trying to match, you could figure out lead weights and locations accordingly.  The hard part might be coming up with the curve to begin with.

>   I am
>reminded, however, of a presentation I saw some years ago by Rich
>Baldessin.  In short, he had a customer who complained of an action that
>was too light.  Taking lead out of the keys did not seem to solve the
>problem adequately.  Anyway, to make a long story short, he found that in
>order to satisfy the customer, what was needed was to add two leads, one
>behind the balance rail and one in front, equidistant from the center. 
The
>net effect on the balance weight would have been zero, but the,
presumably,
>increase in inertia was what the pianist was looking for.

I think this shows that different pianists have different ideas about how pianos ought to feel.  I think we have been lead to believe that there is an ideal setup and we just have to find it.  I wonder if we shouldn't be working towards having the ability to vary the feel of the actions more in a quantifiable way to give pianists more choice.  Some might like heavier, some lighter.  Some more inertia, some less.  Some evenness from one end
to the other, others a graduation from one end to the other, etc.  Now, to the extent that we give them any choice at all, it seems to be - you can have this balance weight or that one.  Sort of like saying, what flavor would you like, vanilla or french vanilla.  I also wonder if having some of these options might change their tastes somewhat.  I sometimes hear technicians say that pianists like 10 mm keydip, heavy actions, lots of inertia, 
etc.  Not surprising, since that's what most of them play on all the time.  They don't have much choice.  And most of them don't like change.  But if they were given a chance to live with some other setups I wonder if they wouldn't end up preferring them.  (I suppose this is a bit like the temperament discussions).

>  So, my thought
>was that in order to compensate for the decrease in hammer weight and
front
>weight as you proceed up the scale, all of which subtract from inertia, a
>graduation from front leading to a combination of front and back leading,
>might lead to a more uniform sense of inertia in spite of the apparent
>obstacles.  Then again, it might be much ado about nothing.
>
>David Love
>davidlovepianos@earthlink.net

It would be interesting to have an action on which it was quick and easy to change these various parameters and get feedback from pianists as they tried it with different setups.  Another thing to go on the list of things to do.

Phil F