Thanks, Susan. I was looking for this very file. Finally found it but too
late. I'd saved it as a Word file, not in my piano tech stuff. <grin>
Avery Todd, RPT
Houston
>
> From: Susan Kline [skline at peak.org]
> Sent: Sunday, February 06, 2005 1:50 PM
> To: College and University Technicians
> Subject: [CAUT] Forefinishing post (was: Key frame placement)
>
> At 04:06 PM 2/4/2005 -0800, you wrote:
> >(Maybe Susan has a copy?)
>
> Susan JUST HAPPENS to have a copy -- not having a son to "tidy up" my
> files, I have been able to go right to it. Of course it helps that this
> post dates from 1997, back when I still took the time to sort and organize.
> Back then I thought that if my In Box had 300 posts I was way behind. I had
> yet to discover that Eudora can handle 5000+ posts in a box and (usually)
> not tangle or lose any. Sometimes I wish she WOULD lose some ...
>
> Best,
> Susan
>
>
> **************************************************************************
> In November, 1997, Horace wrote (to Avery):
> **************************************************************************
>
> NY and Hamburg pianos require very different approaches, depending on the
> period of manufacture.
>
> Some background:
>
> Prior to W.W.II, both factories manufactured instruments that, while
> different in certain ways, were virtually identical in others. So much so
> that from the earliest period of the re-establishment of manufacturing in
> Hamburg, NY was shipping everything from action parts to completed pianos to
> London and Berlin, as well as Hamburg. Yes, parts came this way as well, and
> not all models were consistently produced in both plants.
>
> The destruction of the Hamburg facilities through the firebombing of
> Dresden and Hamburg during W.W.II created a real problem. With the end of
> the war, NY had its own problems, and insufficient reserves to rebuild in
> Germany. Enter Louis Renner, et al. Renner offered to rebuild the facilities
> in Hamburg. There was, of course, a catch. The catch was that Steinway would
> have to use actions, back actions, hammers, and other parts from Renner.
> This began the real divergence between the two branches of the company. The
> Renner parts, while generally conforming to NY specifications, actually were
> (are) quite different. The reasons do not matter, the matter just is what it
> is. The results are the differences of touch and tone which we have come to
> expect from the two factories.
>
> What then, are these differences?
>
> Let's start with NY.
>
> The following general procedure was in use up through, roughly, the
> 1987-1988 production period.
>
> First, the location of the keyframe and cheek blocks was set relative to
> the arms of the case of the piano. In the earlier days, the keyframe and
> keybed were then drilled for tuning pins used as locators. Then the back of
> the keybed was planed dead flat. The keyframe was roughly fit to this, (the
> forefinisher could only rough-set this because it was usually done without
> the keys or the stack) and then the dags were installed. The dags were
> located by gluing a piece of 1/8th inch veneer to the back of the keyframe
> (or the front of the dag, if the foreman was not looking), and then
> inserting the keyframe into the action bay and clamping it in place. The
> dags were then glued in place at intervals determined by the location of the
> veneer pieces. After the glue had set, the fit of the keyframe was checked
> again. (There is a lot of misunderstanding about the purpose of the dags.
> They are NOT there just for transportation. They serve the crucial function
> {in the NY pianos} of providing stability for the back rail of the action.
> Too tight, and the action will not shift reliably. Too loose, and the action
> flops around and the touch is not stable.)
>
> When this is done, the keybed is planed concavely front to back along the
> axis of the grain (or perpendicular to the keys, if you prefer). It is
> planed such that the depth of the convexity is app. 1/16 inch; and its
> deepest point is under the center rail of the keyframe. Then 1/8th to 1/4th
> inch of the leading side of the top of the keybed is planed convex by 1/32nd
> to 1/16th inch, with the high point at the center of the keybed. The leading
> 1/8th to 1/4th inch of the leading edge of the underside of the front rail
> is then planed to be a mirror image of the keybed; that is, convex in the
> opposite direction by 1/32nd to 1/16th inch. The keyframe is constructed so
> that only the end stretchers between the front and back rail are flat. These
> are then planed so that they do not touch the keybed, save at the narrow
> areas described above. The procedure for locating the cheek blocks has
> varied over the years. The most prevalent iteration being to use the
> location as set from the arms, and then locate the brass guides relative to
> the pins in the keyframe.
>
> Once that has been done, the keyframe can be inserted and clamped in place
> with the cheek blocks, and the forefinisher can work to perfect the mating
> of the keyframe and keybed with (hopefully) fine sandpaper. This whole thing
> is a part of the overall forefinishing process, which, in Steinway's case,
> is a patent process. (Basically, that means that not only can it not be
> copied, but they cannot vary from it and still legally use the descriptive
> language from the patent documents.) The purpose of this section of the
> forefinishing process is to provide the most solid connection of the action
> to the balance of the piano possible, so that the pianist may get the
> feedback of the vibrations of the piano through the keys. (This speaks
> directly to the recent threads on the forum, re: "singing rims" etc.) The
> original patent documents describe this feedback quite dramatically and make
> interesting reading anyway...
>
> This process was used from very early on, right up through the use of the
> Pratt-Read keys and keyframes, until 1985, when the switch was made to
> Renner action parts and Renner and Kluge keys and keyframes. Servicing
> keyframes from this period is usually a process of figuring out what was
> done during the original manufacture and why it was done. Most often, in my
> experience, this has involved some degree of seeing through the mist created
> by some well-meaning, but ill-advised colleague. Basically, even if some set
> of arbitrary numbers seem to be out of whack, if the original work seems to
> have been done a certain way, just follow that. There is usually some (good)
> reason that something was done, and most of the time, you just have to redo
> your own work when you find out why.
>
> These pre-1985 keyframes were made of heavy Oak, Walnut and Maple. They
> were well seasoned and held regulation well. The Renner/Kluge keyframes are
> made of European species, are much lighter and are designed for a different
> kind of piano altogether.
>
> Beginning in 1987-1988, NY began planing the keybeds mostly flat, with
> areas of concavity around the maple plugs for the glides. While some
> improvements have been made over the earlier keyframes, they are wildly
> susceptible to weather changes, as I am sure you have discovered. Further,
> their lightness of mass influences not only their ability to hold
> regulation, but also their ability to transmit energy. Their planing in the
> front rail area is usually limited to the last 4-6" of distance from the
> ends of the keyframe, and seems to be further limited to the keybed itself -
> there is little, if any, attempt to mirror the work. The result, of course,
> is a keyframe which is never quite stable; which brings me to:
>
> Hamburg keyframes.
>
> In the period immediately following W.W.II, the Hamburg pianos were, at
> first, just put together from whatever could be salvaged from London and
> Berlin, as well as Hamburg. There was also, for a time, some bigger pieces
> coming from NY. But it was a different world. The influence of Renner can
> hardly be overstated. Renner was, and is, the world's largest producer of
> piano parts. They make parts to manufacturer's specifications, to be sure;
> but, the manufacturers make sure their specifications fit what Renner is set
> up to do. No company was/is more in this predicament than Steinway. Has it
> been all bad? Definitely not, but it has significantly influenced the course
> of the company. So, what about Hamburg?
>
> What about it, indeed?
>
> Because things were in turmoil for a while, I will take an arbitrary date
> of 1960 for talking about Hamburg keyframes. Yes, it was mostly stable
> during the preceding 15 years, but there was variation. Anyway, the post
> W.W.II Hamburg piano became a truly European instrument. Nowhere is this
> more true than in the concept of the action, and its relation to the rest of
> the piano.
>
> In Hamburg, the keybeds are generally dead flat. None of the planing
> described for the NY pianos above. The action frames are what you see on the
> post-1985 NY instruments, lightly built and highly susceptible to weather
> changes.
>
> The installation is markedly different as well. All of the fitting is done
> to predetermined dimensions. Keyframe, cheek block, dag and action placement
> are done independently. At one point (I think it is no longer the case), the
> entire action was introduced as a finished unit quite late in the
> manufacturing process. The keyframe itself, while arched, is so light that
> it depends on the glides for structural support. These actions depend for
> their bedding on making things work. The keybed, being flat, does not lend
> itself to being replaned. The keyframe, in many of the ones I have seen, is
> only planed toward the ends, so that it is a relatively sharp angle.
> Smoothing this angle is sometimes all that is needed.
>
> END
>
>
>
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