Urgent need of help with three technical terms

[A440A at aol.com]

<< It is rather the angle between the shaft and the strings at impact. <<

    Tht would be "deviation from parallel".

>>This has 

to do with balance; if only gravity were the acting force, a relatively 

heavy bass hammer balancing against a light butt and back stop wouldn’t be 

as inclined to returning to its starting position as a light treble hammer 

balancing against the butt and back stop. >>

   I don't know about this.  Gravity doesn't care how big something is, ie. a 
big steel ball doesn't fall any faster or slower than a smaller one.  The 
gravity-based restorative force on a large hammer are no different than on a 
smaller one, however, given equal friction in both systems, the additional mass of 
the heavier hammer will actually give it more advantage over the friction, 
and it should fall faster.  (notice, that with equal amounts of verdigris in a 
piano action, the topmost treble hammers will return much slower). 

Regards,



Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html