[pianotech] key leveling with a curve - clarification

David Skolnik davidskolnik at optonline.net
Fri Oct 15 08:00:05 MDT 2010


Boys, Boys, Behave!  My excuse was 2 AM...that is, my excuse for 
being careless and rambunctious.  Al didn't have his coffee yet, nor 
I, but I think you're both misinterpreting my thoughts, though 
likely, not my ignorance.  Let's accept that as a given, but, Al, if 
I were to be suggesting  that Steinway was doing something wrong, for 
a long time, would I be the first??  No, so don't be grumpy and 
continue to strive for eloquence.

I have to say that I'm disappointed by Horace's response, or, to 
quote Ron N, I just did.  After:
>There is so much confusion and misinformation about this that it is 
>really frightening.
I was prepared for a thorough learning experience.  Instead, I just 
feel rather misunderstood.  The contextual framework of my comments 
was the discussion about the reasoning behind crowning the key level. 
Given the general consensus that it is subjective and acceptably 
accomplished either crowned OR straight,  forefinishing would seem an 
unlikely determinant.   But let's see if I can make things a bit 
clearer, for myself, at least.  Please correct any misconceptions:

In a perfectly executed Steinway, the key bed is flat at the back 
rail area, straight at the balance rail area, and convex at the front 
rail area, with a concave from front to back.  The key frame, in 
turn, would be flat across the back rail, flat across the balance 
rail (along the top and bottom, and the front rail is slightly convex 
along the bottom contact surface.  The underside of the frame should 
be concave from back to front.

The flex that is created by securing the keyblocks affects the front 
rail, not the balance or back rail, in theory.  If this is incorrect, 
please explain.  Because the key level is a function of the balance 
rail, it seemed absurd to me to connect the crowning of the key level 
with some, slight curving of the front rail.

On the other hand, I recall an earlier discussion about the function 
of the rear dags (contact frame or no?) and the practice of flexing 
the keyframe, using the glides, to get a more positive connection 
between keyframe and the rest of the piano, which was thought to have 
a positive tonal  effect.  Since the bass and treble ends are locked 
in by the key blocks, there would tend to be more flex towards the 
middle.  Isn't it possible that bedding the balance rail in this 
manner could effectively 'crown' and previously flat key level?

Apart from that, I would like Horace to return to my first 
misconception, about why the 'settling' argument doesn't make sense, to me.

Always appreciate the food, for thought or otherwise

David Skolnik
Hastings on Hudson, NY




>Horace,
>
>Thanks for the wonderful reply to Dave, Mine is not going to be so 
>eloquent. I am taken back by your vast knowledge of the Steinway 
>piano and processes.
>
>
>Dave,
>
>Somehow you misunderstood and thought it was my argument and didn't 
>read where I said it was the manufacturing process at Steinway.  I 
>think you should write to them and explain how they have been doing 
>it wrong for all these years and how it doesn't really make sense to you.
>
>Oh well, I haven't had my coffee yet or maybe I just woke up a 
>little grumpy this morning.
>Open-mouthed smile emoticon
>
>
>Al -
>High Point, NC



At 03:47 AM 10/15/2010, you wrote:

>Hi, Dave,
>
>At 11:30 PM 10/14/2010, you wrote:
>>Sorry Al, neither argument seems logical, at least not at 2:00 AM.
>>First, the idea that crowning the key level accurately anticipate 
>>the settling of the keys is absurd.  Is that for a piano that;s 
>>played heavily, lightly, or not at all?  And how much settling 
>>would be taking place with half-rounds, vs. felt punchings?  David 
>>Love pointed out the dilemma faced once any settling HAS occurred: 
>>do we recrown? in which case we obviate the premise that we're 
>>doing it to end up with a level keyboard. or do we pull out front 
>>punchings to restore aftertouch.
>
>Let's put this aside for the moment.
>
>>As for any keybed radius... what are we talking about?  the entire 
>>bed or the front rail?  Clearly the concept of creating opposing 
>>curves to establish positive interface between the front rail and 
>>the keybed  would apply to just that location: the front rail.  But 
>>that's not where we establish key level.  The balance rail 
>>interface doesn't depend upon flection to achieve positive connection.
>
>There is so much confusion and misinformation about this that it is 
>really frightening.
>
>In a traditionally forefinished NY S&S (specifically, one in which 
>the work has been properly done), there are multiple curved and 
>planar surfaces.  That is, some are supposed to be dead flat (for 
>example, the bottom of the trailing/back edge of the back rail of 
>the keyframe and the area of the keybed on which it rests).  Others 
>are supposed to have opposing convex radii (created by whatever 
>means, but equal and opposing).  Still others are supposed to have 
>opposing concave radii (again, created by whatever means, but 
>nominally equal and opposing).  If you remember how Chris Robinson 
>used to talk about pairs of opposing involuted curves in the action, 
>you get a similar picture.
>
>A part of the issue (and, not a small one) is that, as with so many 
>other things in piano manufacture, things have changed a very great 
>deal over time.  This is precisely why, at least as to NY S&S 
>instruments, one size simply does not fit all when it comes to 
>making things work.  While it is absolutely true that those who do 
>substantive rebuilding have an opportunity to make some changes, 
>even during that process, there are limitations unless one is 
>willing to do things like completely replacing the keybed, change 
>the frazing on the top of the inner rim, etc, etc, etc.  There are, 
>as is often demonstrated on this list, a number of people who can 
>and do do this kind of work.  Putting aside for a moment the whole 
>range of discussions which then arise around whether or not 
>something is "better" or is "still" a 
>Yamawaisteinchickwinbechendorfer after such redesigning and 
>rebuilding has taken place; most technicians simply do not have the 
>time (even if they have the skill set) to do that kind of thing; 
>and, even if they do, do their customers want or need that kind of 
>work and can they pay for it?  Not everyone who owns tools falls 
>into that rarified category; and, even if they do, are their 
>customers willing to eviscerate the resale value of their instruments?
>
>Believe it or not, this really is not off-point.  Without regard to 
>how well or how poorly the forefinishing process is carried out on 
>any specific instrument, it is a per-instance piece of custom 
>work.  It simply is not going to be identical at all times and in 
>all places.  Our job is to take each instrument as we find it; and, 
>taking into account the overall situation of the piano, it's uses, 
>owners, their budget, our skills, etc, etc, etc, come up with a plan 
>to establish and maintain that individual instrument in the best 
>condition in which it can reasonably be maintained.  Or, put another 
>way, are we technicians, or are we new parts installers.
>
>>The argument...she maka no sense!  but gets a lotta mileage.
>
>With respect, the argument makes perfect and demonstrable sense.
>
>The problem is that the whole forefinishing process has not been 
>somehow actually publicly demonstrated with either sufficient 
>competency or frequency for enough people to really be able to grasp 
>what is going on during the process so that they have a better 
>knowledge of how things (should) fit and why, and can better 
>diagnose and treat issues as they arise.  Everything runs from deck 
>height, as measure from the top of the keybed to the underside of 
>the string at note 62.  To the extent that measurement is incorrect, 
>everything else in the entire forefinishing process is compromised 
>(beyond the state of compromise required for things to work even 
>when that measurement is spot on).  This has been discussed at great 
>length here a number of times before, so I'm sure there are a number 
>of entries in the archives.
>
>The importance of this latter is painfully obvious the minute one 
>sits down to a "remanufactured" (e.g., "Heritage") instrument, and 
>discovers that the damper system cannot be regulated because the 
>blocks have been mislocated; and they have been mislocated because, 
>in the installation of the new S&S/Kluge keyframe/etc, no attention 
>was paid to actually fitting the new action to the existing keybed, 
>let alone working at the same time to modify the existing keybed to 
>mate properly with the new keyframe....etc, etc, etc.
>
>Anyway...always more food for thought.
>
>Best.
>
>Horace

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