Key Leads and Inertia

[Bill Ballard]

At 11:51 PM +0200 4/29/03, Richard Brekne wrote:
>- Thirdly.... aside from a basic rule of thumbs as to what the 
>general dynamics
>affect of key lead amounts and placement, how does this detract from the
>equation based static balance approach to action balancing ?. Static balancing
>is easy, and can yeild various sorts of eveness in as much as FW can be
>accomplished in several ways. If we simply know some general consequences for
>various configurations of key leading... those can be made to conform to just
>about any given FW specification easily enough... or what ?

Stephen Birkett answered quite neatly that the same counterbalancing 
lead moved from under the finger at the front towards the key's 
fulcrum, yields more acceleration for the same size blow. Maybe he 
can answer this next question: if two keys of identical static 
balancing yet different placement and masses of lead do yield 
different accelerations for the same blow, what does that graph look 
like?

Anyone else willing to send Stephen a box of chocolate chip cookies 
for a picture of this? I am.

At 6:19 PM -0400 4/29/03, John Hartman wrote:
>These static particulars are only relevant if the piano is played 
>very softly. Once the action gets up to speed (accelerated) inertia 
>and compliance become far more important.

John, have we defined compliance, and is it distinct from inertia. Or 
is it the absence of inertial resistance, which would allow a key to 
respond to a pianist's touch with more compliance. The test you 
describe seems to be a static one, for flexibility.

(Also, John, your links, including the one in your signature, would 
be immediately double-clickable if you added the prefix "http://" to 
[link redacted at request of site owner - Jul 25, 2015]

Bill Ballard RPT
NH Chapter, P.T.G.

"We mustn't underestimate our power of teamwork."
     ...........Bob Davis RPT, pianotech '97
+++++++++++++++++++++