Touchweight query

kam544@flash.net kam544@flash.net
Sat, 29 Jun 2002 21:30:37 -0500


List,

I am reviewing some fundamental principles in downweight/upweight 
[UW/DW] concepts and have come across a minor puzzle in this older 
vintage grand piano.

Two notes:
1) one reads 48 grams DW, 28 grams UW
2) one reads 56 grams DW, 28 grams UW

My interest was to have the 56 gram DW number be closer to the 48 
gram UW number without adversely affecting the 28 gram UW number.

However, this is where my minor puzzle begins.

Some information:
Hammer flange pinning is equal on both, wippen flange pinning is 
equal on both, capstan to wippen heel appears to be satisfactory, 
knuckle/rep lever appears to be okay. And there is freedom in the key 
bushings.

Additional information:
The weights of the hammershank assemblies of both notes respectively 
are 16.4 grams 16.1 grams.

The weights of the wippens assemblies of both notes respectively are 
20.1 grams 20.8 grams.

I seem to be unable to accomplish my interest. Any ideas?

At your convenience,

Keith McGavern
Registered Piano Technician
Oklahoma Chapter 731
Piano Technicians Guild
USA


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