[pianotech] Piano Key Leveling

[Tom Servinsky]

Keith,
I've read the Steinway manual as well, many of times. Please explain why the Yamaha keyleveling system is much more exact and holds true much longer....without the scooping out of the keybed. I'd say their approach is much more stabile.
Point being, I don't see where Steinway is getting anymore stability from the front rail in their way of thinking. I find that there's much more settling occurring in a new Steinway keyboard than any of the pianos from Japan, which uses a different approach.
This really is a design issue which goes back to the introduction of the una chordal pedal. If the action could remain in one position, none of these issues would even be talked about today. It was when the designers were told...."and by the way, we want the action to shift over for this special effect..." that the engineers had to find ways to take the weight over the center of the keyboard as much as possible, allowing the action to move easily without resistance. Thus this whole concept of how the keybed should be fashioned. Correct me if I'm wrong but isn't Steinway  the only company that scoops out their keybed in this fashion?
What Eric Schandall was explaining to me was that even if the bottom is of the keyframe is carved out, couldn't they still maintain a straight keyleveling? And the answer from Eric was, yes. He maintains that there is a firmly planted notion that keyboards with crown appear more level than straight-leveled keyboards.
Personally, I think this whole approach was the result of  the factory putting a little fudge factor in their leveling to account for settling.
...and the old wive's tales continue
Tom Servinsky


  ----- Original Message ----- 
  From: Keith McGavern 
  To: pianotech at ptg.org 
  Sent: Saturday, June 27, 2009 7:22 AM
  Subject: Re: [pianotech] Piano Key Leveling


  Tom,, List,


  While it may or may not be true that a crowned keyboard gives the appearance of being level from a distance, that is hardly the reason for doing crowned key leveling in Steinway grand pianos. The following reasons have been presented already on the Pianotech List by me, and I post them again for your perusal.


  This is directly from the Steinway & Sons Technical Service Manual that I had have in my possession since 1992.


  ------
  Bedding the Keyframe to Keybed
  Background: Steinway utilizes a keybed which is shaped and planed in such a way that it provides the keyframe with a solid support structure and minimal friction.


  Features:
  1) The front lip of the keybed (1/2" approximately), which contacts the keyframe is crowned so that its center is approximately 1/32" higher than the ends.
  5) The front rail of the keyframe is reverse crowned so that the center of the front rail is approximately 1/32" lower than the ends. This is done to ensure stability at the front rail. There should be no gaps along this line of contact.
  (page 11)
  -----


  This clearly shows that when the keyboard is held in place with keyblocks, leveling the keys correctly should follow the line of that crown as recommended by Steinway and should not be leveled flat.


  Now interestingly enough, and which had not been mentioned before in this thread, crowned key leveling also applies to Steinway verticals as well. (p80)


  The real question remains: "When did the Steinway company actually implement this crowned feature in its pianos?" I have physical records that indicate crowning the key level has been published in their service manuals since somewhere in the 1960s'. Prior to that time is unknown by me.


  Sincerely,


  Keith


  On Jun 27, 2009, at 4:56 AM, Tom Servinsky wrote:


    Just returning from a trip and noticed a lot of interest in the idea of crowned key leveling. On my many trips to the Steinway factory,I was always posed that as my first question. Why the need for the crown keyboard? I've heard one reason after another, none which made any sense. That was until Eric Schandal was finally kind enough to give me the real poop.
    Crowned keyboards look level from a distant. Level keyboards look concave. Plain and simple. 
    They've done it that way for years and I'm sure they'll continue to do it for years to come.
    Remember...there's the wrong way, the right way, and then there's the Stein--way.
    Tom Servinsky
      ----- Original Message -----
      From: Keith McGavern
      To: pianotech at ptg.org
      Sent: Sunday, June 21, 2009 10:54 AM
      Subject: Re: [pianotech] Piano Key Leveling




      On Jun 21, 2009, at 9:36 AM, Gerald Groot wrote:


        One question is, was this level board meant for the older pianos that called for possibly more crown in the middle or perhaps more crown than what today's pianos call for? 


      Gerald,


      The only piano I've heard of that calls for a crown in the middle is Steinway grands.


      Keith

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