Action Spread S&S -Reply

[Horace Greeley]

Michael,
 
A couple of thoughts.

First is that, if you are using Renner parts, you may
find it easier to work with the metric measurement,
in this case 112.5 mm (nominal).  (And, of course,
have to go back and forth between English and metric
measurements... :-) .)

Second, since until fairly recently (in S&S terms, anyway)
the action rail alignment can be, well, inaccurate (to
say the least), just as important is going to be the
rake of (especially) the hammer flange rail.  (Nonimally
2-3 degrees.)

The point here is that, until post '85 production, the
entire action/forefinishing integration (for NY S&S) was
part of what is/was referred to as a "patent process".
(e.g., Not only specific materials can be/are called out
in the patent, but, more specifically, the process by
which a given production/manufacturing end is acheived
is patented.  Among the problems with this approach is that,
while you protect, to a certain degree, a given process, you
are also limited as to the range and domain of the changes
which you can make and still either protect the process, or
use the identifiers under which it is protected.  Two prime
examples of this are Kodak, with the Kodachrome process;
and S&S, with the accelerated action.)  

The obvious point, which I apologize for pointing out since I am
sure that you know it, but others may not, is that spread, in and
of itself, is only one variable in an overall complex system of 
gears (in the form of opposing involuted curves) and levers.  So 
that, while a change of plus/minus 0.5mm might make one
difference in the way an action (subjectively) feels (with the same
down/up weights), a change of 0.5 degrees in the rake of the
hammer flange might produce another.  Chris Robinson, Del
Fandrich, and Dave Stanwood can all address the theoretical
issues behind all of this much better than I, and I immediately
defer to them.

Best.

Horace



At 10:00 AM 5/26/1998 -0600, you wrote:
>4.44".
>Vince Mrykalo RPT MPT IPT BA HA HA
>vince@byu.edu
>
>>>> "Michael J. Wathen" <michael.wathen@uc.edu> 05/26/98 07:15am >>>
>Does anyone know what the action spread distance should be on a Steinway D
>from the 30s', the distance from the whippen flange center pin to the
>hammer shank center pin?
>Michael J. Wathen   For Information about Wapin click on URL below
>michael.wathen@uc.edu  http://ucccm56.ccm.uc.edu 
>                                                                  
>
>
Horace Greeley, CNA, MCP, RPT

Systems Analyst/Engineer
Controller's Office
Stanford University

email: hgreeley@leland.stanford.edu
voice mail: 650.725.9062
fax: 650.725.8014