----- Original Message ----- From: "Bill Ballard" <yardbird@vermontel.net> To: "Pianotech" <pianotech@ptg.org> Sent: June 08, 2003 11:35 AM Subject: Minimum LO, WAS: Hammer assist spring ? > At 9:45 AM -0700 6/7/03, Delwin D Fandrich wrote: > >This is the part that intrigues me. The ability to set very close > >letoff and the ability to control the action at pianissimo levels. > > At 7:46 AM -0700 6/8/03, Delwin D Fandrich wrote: > >So, when I hear some say some grand action design can be regulated > >with let-off right up to within 1 mm of the string line I at least > >want to give the thing some thought. And one of those thought is, "I > >wonder how this thing would work with a nice graphite-filled ABS or > >Nylon jack?" > > Escapement friction is a turnstile. You can reduce the hiccuping by > fattening the LO. But the size of this friction determines the > quietist sound one can get out of a piano. So Del, would the > lubricity of the jack top make a big difference here? In the Herz/Erard action I think you are analyzing--none at all. Or at least very little. But, in the Herrburger/Schwander Inverted-center Linked action (as illustrated in the post I was responding to) I think quite a great deal. This action has a sliding let-off and a sliding return mechanism. I should think providing a precise and low friction surface for these two functions would be important. Del
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