[pianotech] Perfect dip/blow/aftertouch

[David Stanwood]

Jon Page wrote on the subject "Hammer Blow":

<snip>
>alter the dip not the blow distance. Keys level, hammer line
>level, key dip slightly uneven. The pianist feels a even aftertouch and
>not an uneven key dip. Altering the blow on an individual basis will
>introduce volume discrepancies brought on by varying blow distances.

>Aftertouch calibration by varying dip slightly is essential to a smooth
>feeling action.

Hi Jon,

You raise a very interesting point.  When I first realized that 
making "Perfect" key dip with "Perfect" Hammer Blow yielded 
"Imperfect" aftertouch I was fresh out of North Bennet St. School in 
1980 or so.  When I started doing weight ratio studies in the '90's 
the culprit was revealed as unevenness of the ratio from note to 
note.  Developing the half cut punching technique and playing with 
modifying the balance rail bearing point with veneer shims and the 
like led to a solution for "Perfect" aftertouch with "Perfect" key 
dip and "Perfect" Hammer Blow.  This solution is to set up your 
punching stack such that a thick cardboard punching is at the bottom. 
Glue the cardboard punching to the balance rail then trim portions 
off the front or back side of the punching to alter the ratio 
slightly as needed from each note.  This evens out inconsistencies in 
the ratio from note to note and makes it possible to achieve even 
aftertouch with even dip and blow.   Sorry, doesn't work for 
Accelerated Actions!

This solution didn't come from a quest to solve the aforementioned 
problem of uneven aftertouch.  It came from my quest for perfection 
in action balancing.  I had eventually come to the point were I could 
balance an action with perfectly consistent Strike Weights, Front 
Weights and Friction Weights from note to note but the balance 
weights turned out to be inconsistent to varying degrees because of 
ratio inconsistencies... the solution to perfection was the 
aforementioned method.

I might also note that part of the definition for "Perfect" from 
Dictionary.com is:
"complete beyond practical or theoretical improvement"   You (we) can 
be the judge.

Regards,

David Stanwood