[CAUT] More hammer length needed

[Bob Hull]

I am building a new top action with WN&G Parts.  The piano is a 1923 Steinway M. The needed hammer lengths after calculations is from 42.5 mm in the low tenor to 45 mm in the high treble.
Bass hammer calculations call  for 50 mm hammer boring in the low bass up to 52 mm at the top of the bass section. Obviously this would have me drilling just about into the felt on the lower ends of the sections.   The old hammers are raked I guess to allow more hammer length. I don't want to rake the hammers on the new action.  What do you think about planing down the key frame bottom or rails to remove 2-3 mm of height ? I am installing new key pins anyway. Also,  The clearance above the stack to the pin block is barely more than 1/4".  It has been rebuilt at least once already so it's hard to know what the original set-up was.  With WN&G rails and parts I can adjust things much more easily than with the SS fixed rails/brackets. What do you think about this solution of altering the key frame? Somehow I need more distance between the hammer action center and the string ht. in order to drill lower on the hammer. 
Bob Hull
Sent from my iPhone