Hi,
My apologies for the delay...it's been a long day.
Anyway, here is some more information:
String height as noted, is critical; and, there are many possible
variations.
From notes that I used to prepare a forefinishing class I used to teach
and from a class done by Michael Mohr some years ago, string height is
generally measured at note #62, with the optimal numbers being:
- Models S through B - 7.5"; and,
- Models C and D being - 7-5/8th"
These are, however, only very general guidelines as the casting of the
individual plate varies based, in part, on which of the several wooden
patterns were used to create the sand mold into which the iron was cast.
Other important variables include how the plate was fit into the case,
which, in turn, is based on the actual contours of the seasoned, bent
rim. Important to remember that the variable of plate fitting a crucial
one which is often not properly set in the factory, let alone by many
rebuilders. Especially for a sole proprietor, while taking time with
this step can be a real PITA, getting the plate in at the proper height
saves oceans of grief with every aspect of getting the piano to work
properly thereafter.
Also, as Ed Foote notes, it is normative for the strings of the lowest
note of the low tenor on any given scale to be anywhere from 2 to 4mm
lower than those at note 62. Similarly, it is not unusual to find the
strings of note 88 to be around 2mm (or so) lower than those of note 62.
In spite of efforts to bring production between NY and Hamburg into
greater continuity, manufacturing processes in Hamburg are still
generally more advanced than those in NY, with the result that there
continues to be more instrument-to-instrument variation on this side of
the pond. There's a long story about all of this...for another time.
Obviously, the "rebuild" introduces many additional variables. I'm not
sure that I'd be too worried about the below-plane agraffes as long as
the bearing wasn't excessive for the board, and/or, the string height
for those last few agraffes didn't wind up more than 4 or 5mm below the
7.5" (plus or minus...depending on how closely to the optimum number the
plate was set to begin with).
Among the problems in doing patent research is that the potential
patentee (as it were) is often justifiably worried about whether or not
their R&D work might be stolen by others. So, it's not unusual to have
to dig through the text carefully for clues from which to assemble some
reasonable insight into the actual intent of the design submitted.
One very good example of this are the two main patents associated with
the (eventual) patenting of the accelerated action...#1,826,848
(13Oct1931) and 2,031,748 (25Feb1936). Both patents are the eventual
product of engineering development begun in the mid-1920's, and in
production (at least in the Model D) at least as early as 1929. The
specific example of the above noted kind of writing appears on Page 2 of
the application for the earlier patent (1,826,848), lines 110 through
119, inclusive. I'm attaching copies of both patent applications...with
any luck they'll come through.
OK...this is not as much detail as I had hoped to have. I'm presently
kicking off a restore from tape of several archived areas of my notes to
see if I cannot find more relevant documentation for some of the patents
which come into play with all of this. I know that I put all of those
documents in a Very Safe Place...now, of course, all I have to do is to
remember where that is. My sincere apologies. I thought that this
stuff was more immediately to hand. Maybe Bill Shull has something more
readily available.
In the meantime, I hope that this is of some use.
Kind regards.
Horace
On 2/18/2018 6:02 PM, Edward Foote via Piano Technicians Guild wrote:
> Please do not forward this message due to Auto Login.
>
> Greetings,
> ?? ??It is the norm for note 21 on a Steinway B to be significantly lower than note 52. ??2-3 mm is not abnormal in my records. ?? I have heard the expanse of understring felt that the string rests upon between agraffe and tuning pin called the "apron", "string shelf", and "string rest". ??I don't know if it really has a specific name.
> Regards,
>
> ------------------------------
> Ed Foote RPT
> ------------------------------
> -------------------------------------------
> Original Message:
> Sent: 02-18-2018 18:15
> From: Jon Page
> Subject: Steinway B circa 1988 - 2 1/2 questions
>
> "It's not a fault, it's a feature."
>
> ------------------------------
> Regards,
>
> Jon Page
> ------------------------------
>
> Original Message:
> Sent: 02-18-2018 16:02
> From: Horace Greeley
> Subject: Steinway B circa 1988 - 2 1/2 questions
>
> Hi, Ed,
>
> No...it's part of the design.
>
> Kind regards.
>
> Horace
> ?? Original Message
>
>
> Original Message------
>
> One thing might be to measure the string height from keybed, across the scale.
> Is this an attempt to compensate for some structural irregularity?
>
> ------------------------------
> Ed Sutton
>
ed440@me.com <
ed440@me.com>
> (980) 254-7413
> ------------------------------
>
>
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Original Message------
Greetings,
It is the norm for note 21 on a Steinway B to be significantly lower than note 52. 2-3 mm is not abnormal in my records. I have heard the expanse of understring felt that the string rests upon between agraffe and tuning pin called the "apron", "string shelf", and "string rest". I don't know if it really has a specific name.
Regards,
------------------------------
Ed Foote RPT
------------------------------