Low Inertia

[David Love]

As one who routinely redesigns actions I'm not sure I would agree that key
lead doesn't play a role in inertial feel of the downstroke.  While I can't
provide the math I can say that I have on several occasions taken actions
that were balanced but where the action geometry had left them with
excessive key leading.  With a simple move of the capstan the removal of
lead, rebalancing the action back to the same balance weight the action
"feels" considerably different, less "inertial" as it were.  

That being said, I can say that inertial feel seems to be also related to
knuckle hanging/hammer weight.  The longer the knuckle to center distance,
the less the inertial feel all other things being equal (slight
complications to get all other things exactly equal, I realize).  In other
words, given the same strike weight, a longer knuckle hanging will require a
slightly greater balance weight to have the same feel as a shorter knuckle
hanging.  I say this having had to use 18 mm knuckles on several occasions
and discovering that I need to push up the balance weight by 2 or 3 grams to
get the same feel as my more standard setting of 37 grams BW.  

While this is only anecdotal it would seem to me that the inertial component
is influenced by both the hammer weight/knuckle position and the amount of
lead in the keys.  

David Love
davidlovepianos at comcast.net 
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Norm Barrett
Sent: Thursday, October 02, 2008 8:20 PM
To: Pianotech List
Subject: Re: Low Inertia

Jim,
I am not heavily into redesigning actions or even a great pianist for 
that matter but your post was very interesting. The question that comes 
to my mind is have you had the opportunity to play the Horowitz Steinway 
piano? If so does that piano have the feel you would like? My impression 
playing that piano was that you could breathe on those keys and they 
would play and respond wonderfully.

Norm Barrett

jimialeggio5 at comcast.net wrote:
> List,
>
>   
>> ... the excess lead wouldn't be in the keys in the 
>> first place unless the hammer weight is too heavy for the 
>> action ratio. I don't think key lead has a lot to do with down 
>> stroke inertial feel.
>>
>> My take,
>> Ron N
>>     
>