upright touchweight

[ed440 at mindspring.com]

Let me try once again to express my somewhat out-of-the-box thinking about touch in the vertical piano.
-In a grand action, hammer weight, moment of inertia of the hammer and friction are intimately connected.  Increase the hammer weight and you increase all of these.
Increase the hammer weight and you also increase the contact time of the hammer to the string, which changes the timbre of the piano.
Increase the hammer weight and you increase both the static down weight as well as the "active touch weight" felt at the key front. 
-In a vertical action, the hammer return spring creates "artificial gravity," but no mass is added.  In the vertical action the inertia and "spring weight" of the hammer are "divorced."  For example, increasing the "weight" by strengthening the string will cause the hammer to leave the string sooner, thereby making the timbre brighter.  You could strenthen the string on a hammer butt with no hammer attached to create whatever static down and up weights you want in the vertical.
-Remember, we have no cost effective method of measuring the inertia of the action in our shops. Gram weights give static measurements.  However, feedback from an intelligent player can be quite valuable.
-So back to my original suggestion: Forget about the measurements and formulas. Add a small amout of weight to the hammer heads, play the piano and see what happens. 
-I have tried this three times with good results on two.  First the pianos were well voiced, but still left something to be desired.  I added Office Depot #825-182 Small Binder Clips to the shanks just below the hammer heads.  I found the pianos to be more expressive and responsive.  In particular I was able to produce a better range of simultaneous contrast of dynamics.  I was able to play pp subordinate chords without feeling I was "walking on eggs."  The overall timbre of the piano seemed warmer. 
-I'm guided in this by the premise that inertia in the system that doesn't move a hammer is wasting energy.  Adding extra weight to a key to increase the down weight is just for weight lifting. I want my weight lifting to have expressive consequences.
-I do not claim certainty given the small range of my testing of this hypothesis. I would appreciate it if anyone else would try it and give some feedback on the results...not measurements but comments from the player about whether the piano feels different or more expressive or better or worse.
Thanks.
Ed Sutton


-----Original Message-----
>From: Cy Shuster <cy at shusterpiano.com>
>Sent: Dec 20, 2006 6:40 AM
>To: Pianotech List <pianotech at ptg.org>
>Subject: Re: upright touchweight
>
>Speaking of the Fandrich action, another important factor for DW is the 
>hammer return spring strength, which was adjustable with a screw on their 
>earlier actions.
>
>--Cy--