Pinning and Tone

[fssturm@unm.edu]

Quoting Ed Sutton <ed440@mindspring.com>:
> Fred-
> 
>     I agree with your assessment of the limitations of testing with the "Stanwood
> flange," but I think it's a place to start.  The experiment would be controlled
> for one variable, and the hammer alignment would not be changed.
>     If the experiment shows a different wave form, then great, something has 
been
> experimentally confirmed.  If not, then everything else you said is still true.
> Either way, we continue doing everything we can to make pianos sound 
better.
>     I wish it were possible to get high speed films of the action at work in the
> piano, but so far as I know that takes a very expensive lab set-up and is done
> with action models, not real pianos.
> 
> Jim Ellis-
> 
>     If you want to do this, and want me to help, I would be honored!
> 
> Ed Sutton

   I agree it would be a very interesting test, and that a flange modified as David 
Stanwood did would produce useful results. It would be nice to do repinning 
also, though. I think this could be fairly closely controlled - using Mannino 
broaches and long burnishers to get both the loose and the tight (maybe a 
smaller size burnisher for the loose, then stepping up a half size with 
appropriate burnisher for tight. At any rate, trying to do something measurable 
and standard. Maybe some stab at unequal looseness - one side tighter than 
the other). 
   To eliminate other objections - or at any rate address them the best we can - 
make sure the hammers are filed beautifully (no grooves), strings are level, and 
hammers are mated. Then carefully reproduce flange spacing and hammer 
spacing to string. It won't be perfect, but at least reasonably close. For the sake 
of control, one could remove and replace a couple times without any changes, 
and see what variance there was.
    To produce a range of blows, a Disklavier or Pianodisc system could be used. 
A range of volumes could be recorded and reproduced. The test blow devise for 
the tuning test is not very close to a humanly produced blow, for various reasons 
(in particular, the fact that the device has reached a fairly high velocity at the 
point of contact with an inert key, and there is a lot of bounce and loss of power 
at contact. And bounce at key bottoming as well, meaning bad checking. Jim 
Ellis worked hard to create a devise that would overcome this problem - by all 
accounts pretty successfully - using some kind of internal damping mechanism. 
But still, this is a harsh, unmusical blow. a lower volume range would be better).

Regards,
Fred Sturm
University of New mexico