Action Ratio and Dip and Blow and Etc.

william ballard yardbird at vermontel.net
Tue Jul 3 21:56:31 MDT 2007


On Jul 3, 2007, at 2:05 PM, Farrell wrote:
> I'm working on an 1890s Knabe grand. Everything in the action is  
> new except rails and keyframe (both of which have been rebuilt) and  
> action brackets.

 From the pix, it's clear that this is one of these 19th century  
actions with extremely tall string heights. The line from the Rep  
center to the cap/heel contact looks almost as steeply inclined than  
the line from the hammer center to the knuckle/jack contact. The  
further from horizontal is the swing of your levers, the more of the  
the arc's motion ends up in the horizontal vector rather than the  
vertical. It's a form of action inefficiency aggravated by tall  
string heights. The only solution is to raise the keybed (......what  
is this guy, nuts or sumpin'?)

On Jul 3, 2007, at 4:11 PM, Farrell wrote:
> How can you be so smart to know that this action had lots of lead  
> in the keys?  ;-)

On Jul 3, 2007, at 2:05 PM, Farrell wrote:
> FW: 36.25 (0.966 of Stanwood's maximum FWs)

Speaking of which, you didn't list a SW. (Or was that the "F= 11.5")

Mr. Bill







More information about the Pianotech mailing list

This PTG archive page provided courtesy of Moy Piano Service, LLC