Inertia, was "Grand Touch"

[ReggaePass at aol.com]

In a message dated 7/13/2006 11:33:34 PM Eastern Daylight Time, "Absolute Piano" <absolutepiano at comcast.net> writes:

>Good point Mike. One of the factors that I perceive in keyboards that annoy 
>me is if the keystick feels like a spring board. I perceive more control in 
>a stiff key. Whether this is the material, moment of inertia or both is 
>something I don't often hear discussed in terms of noticing, measuring, or 
>accounting for and yet it is another one of the many important components of 
>touch.
>
>Jude Reveley, RPT

Jude and List,

A subject worthy of our consideration.  This first came to my attention through Del Fandrich in a demonstration that showed a severly underengineered concert grand key stick (from a maker considered to be among the very best!).  Holding down the back of the key at the capstan, he could depress (i. e., FLEX) the front of the key all the way to the front punching.  Power loss?  For sure.  And what is the effective DYNAMIC key dip in such a scenario?  Somewhere between 10mm and a whole lot less than that.

The key on Ron Overs' action model at the Rochester convention was a laminated sandwich (thin layers on the top and bottom), and Ron has been one of the very few at the cutting edge of furthering the state of the art of piano technology, IMHO.  

Pearl River's uprights now use keysticks with three equal laminations.  They may have gone to this as some sort of manufacturing expediency, but it must surely result in a more efficient transmission of power from the player's finger to the wippen, etc.

My two cents worth of observations.

Alan Eder, RPT