David's Stuff -Reply

[Jack Reeves]

>>> Newton Hunt <nhunt@gandalf.rutgers.edu> 01/05/95
07:05am >>>

Hi, All,
<    I was asked if I had any of David Stanwood's recent hammer
weight data.  Unfortunately I do not but he has developed some
reliable figures empirically, by measuring many piano's hammers
 and deriving standards by determining the actions over or under
weight. >

What exactly is "the actions over or under weight"?

  The keys are weighed from the center of the balance pin hole
 to 1 cm from the front end of the keys.  I have made little
fixtures the keys rest  upon to make this chore go faster.

What is the purpose of weighing the keys?  What is it that you do
with those figures?


    These numbers help you find over and under friction points of
the action.  More about this later.

What does that mean?

    If you send the balance weight, front weight and strike  weight
of all C notes and C# notes to David he will return a set  of weight
specs for the strike weights and the front weights  specific to that
action based on your requested balance weights.

Could you specifically tell me the significance of the front and
strike weights when taken together?


    This leaves one other uncontrolled factor, geometry.
    By putting weights on a key with the hammer off the wippen so
that the key is absolutely perfectly balanced then lowering the
hammer and taking the up and down weights one can measure
the  leverage of the entire key unit at that note.

What does it look like when the key is perfectly balanced? With
so much friction there, how do you tell when the key is perfectly
balanced?

     David has just promised to send me a text file to be posted
here in the near future providing much more specific information.
He can also be reached at 508-693-1583 if you need more
informa-  tion now.

I guess my questions are about the basics of this system. But i
would like to understand the significance of all these things you
are talking about. Look forward to hearing from you. Thanks.

vince