Touchweight Metrology Question

[A440A@AOL.COM]

Terry writes: 
>Unfortunately, this piano appears to have new Yamaha hammers on it. But
>they are not tapered, or arced. Friction in the hammer-shank flanges is
>all over the place. Is it reasonable to try the water/alchohol thing to
>shrink-size the bushings before repinning the whole shebang

   I gonna take a wild guess here that the hammers are much heavier than the 
original design called for and the pinning is why the heavy DW's are all over 
the place.  You want an even response, and you will want it to gradually 
increase from perhaps 52 in the low bass to 44 grams at the top.  How this 
curve of decreasing resistance is shaped will depend on the key 
leading,(unless you want to go all out and change SW as well as FW. ) 
   Shrink sizing flange bushings has NEVER , in my experience, produced an 
even friction throughout the 88 centers.  Depending on what sort of job 
quality is expected (and charged for),  I would recommed that you remove all 
the shanks from the action, pin them all to spec, and then bring down the SW 
until the thing feels right.  If you have a key, say C40, that requirs 60 gr. 
DW, then see if you can bring the SW down 2 grams, or so.  You can usually do 
this with a belt sander on the sides of the hammer, or using one of the jigs 
that allows you to taper with shank in place.    
   This vintage Yamaha may have a  movable action(whippen) rail, so pay 
particular attention to spread. 
Regards, 
Ed Foote RPT