[pianotech] Shank questions

[John Delacour]

At 14:30 -0700 24/05/2011, David Love wrote:


>The answer of what one would expect is complicated.  In short, in that
>section of the piano I would expect not much tonal difference at lower
>levels of playing.  The stiffer shank would mean somewhat less ability to
>feel of the hammer at lower levels of acceleration but at higher levels I
>would expect greater power and more consistent tone given what might appear
>to be equal levels of acceleration.  The stiffer shank with the somewhat
>heavier hammer in that section would tend to minimize action saturation as a
>result of the shank flexing.  You would be able to achieve a higher level of
>output or the forte wouldn't top out prematurely.  Since the shank not only
>flexes downward but also twists some then the stiffer shank would also have
>the benefit of keeping the hammer more consistently square to the strings
>through impact.  That would produce greater consistency at higher dynamic
>levels and overall more power.

I haven't gone any further with the experiment yet but will be trying 
the same stiffening at various points in the scale once I have 
completed the fine regulation.  What you say makes sense, but the 
differences I initially observed were two.  The most interesting 
difference is that the attack is clean and the initial short-lived 
'dong' that is heard on its neighbour is now absent -- the pure note 
is there from the very beginning.  The second difference is that the 
sound is brighter, and this is presumably due to a shorter dwell in 
contact with the string owing to the increased stiffness of the shank.


>Generally speaking the stiffness of the shank should work in concert with
>the hammer weight in order to balance feel and control.  More flexible
>shanks will transmit the feel of the hammer head more easily but sacrifice
>control.  Stiffer shanks will give more control but there will be a loss of
>feel...

Yes, that may well be so, but this piano has Brinsmead's patent 
English action, which is very direct and more efficient than the 
French action, so the effect will be felt rather differently.  I'll 
see what I discover as I go on.

Thank you for your interesting observations.  I need to go deeper 
into this subject, not before time.

JD