Lost motion: (was puzzler on M & H BB

[A440A at aol.com]

 JD  writes:

<< Have you got the proper lost motion at the fly?  In other words does 

the cradle support the hammer very slightly above the jack?  This 

lost motion should be barely perceptible when you tap the key 

lightly, but you must have lost motion so that the fly can return 

under the roller without impediment. >>

Greetings, 
   I have to respectfully disagree with this.  Grand piano actions work 
wonderfully with no lost motion, at all.  If there is any lost motion, there will 
never be a straight hammer line as well as accelerated wear of the knuckle( 
from the impact of the jack hitting it rather than pushing it to start.
    We were taught at North Bennett to set the balancier so that we could 
feel the jack scraping, ever so slightly, across the leather of the knuckle when 
the hammer was at rest, and I have never had a problem with this causing loss 
of repetition. 
   Uprights are a different matter. 
Regards, 
 
Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html