Bore lengths

A440A@aol.com A440A@aol.com
Thu, 23 Dec 2004 00:31:59 EST


Richard writes:

<< So what do you folks do here ?  Go with a bench figure, compensate for 

the bedding on the bench, or simply measure in the piano ?  If the 

bedding screws are taken into account... do you always make sure of 

optimal bedding first ?..

I'd like a bit more detailed description of what you all do in 

conjunction with this on the surface simple measurement. >>

Greetings, 
       I have a variety of bore lengths in a set of trial hammers.  These 
have a centerline inscribed on both sides. they are mounted on shanks at exactly 
90 degrees.   I put them in the action, reinstall the action, lift the trial 
up to the string,(damper is removed for this), and put a small square on the 
string to see what bore length gives me a 90 degree angle upon contact with the 
string.  If the piano is going into a heavily used venue, I will often add a 
mm or two to the length so that the longevity of the hammers usefulness is 
increased. 
    This method sidesteps the fact that strings are not always parallel to 
the keybed,(particularly in the top sections of Steinway grands.)  Sometimes, it 
would be necessary to bore longer than there is room for in order to make 
everything 90 degrees, so then a few degrees deviation from 90 on the hammer 
shank allows the hammer to strike the string at 90 degrees and still be able to be 
regulated. 
Regards, 



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

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