Pianotech

  • 1.  Grand Piano Hammer to String Alignment

    Registered Piano Technician
    Posted 12 days ago
    I am familiar with two approaches to aligning grand piano hammers to strings.  The first, which I see documented in the Steinway Technical Reference Guide, the Kawai service manual, and the summary of Yamaha's 37 steps that appeared some years ago at the back of the Journal, is to center the hammers on the trichords.  The other is to place the hammers so that the left string of the trichord is positioned a little closer to the left side of the hammer.  A method for setting this up is to place a 1mm spacer between the left end of the keyframe and the block against which it rests, align the hammers such that the edge of the string lines up with the edge of the hammer, then remove the spacer.

    Now that I go looking, I'm not turning up any documentation for the second method.  Are most of you familiar with both of these approaches?  What do you see as the relative merits of each?  The second approach has been my default one for a long time, but now I'm beginning to wonder if it is a little idiosyncratic.

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    Floyd Gadd
    Regina SK
    306-502-9103
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  • 2.  RE: Grand Piano Hammer to String Alignment

    Registered Piano Technician
    Posted 12 days ago
    I align the hammer to the string so that when I shift the action to the fullest the hammer misses the left string. On some action that makes the hammers exactly in the middle of the trichord. But on some, the hammer will cheat a little to the left.

    Wim

    Sent from my iPhone




  • 3.  RE: Grand Piano Hammer to String Alignment

    Posted 12 days ago
    Yes - this is the proper approach. In order for the misnamed "una-corda" pedal to function the shift has to put the edge of the hammer midway between the left and centre string of each tricord, and on bicords to clear the left string. An adjustment normally on the right hand key cheek prevents shifting too far to the right.

    On turn of the 19th century instruments there was a lever on the right key cheek which adjusted for bi-corda or una-corda shifts but mid century smaller instruments often were bicord rather than tricord so then the una-corda pedal was aptly named.

    (bicord or bichord? etc)

    Best wishes

    David P

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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 1342 850594





  • 4.  RE: Grand Piano Hammer to String Alignment

    Registered Piano Technician
    Posted 11 days ago
    Yamaha, for example, recommends that with the shift pedal engaged the left side of the hammer should just barely touch the left string. By not actually missing that left string you are preventing any twist in the shank from the hammer striking the strings off center. The other objectives are to first reduce the number of strings that are actually being struck by one, and second, to move the hammer so that it strikes the remaining two strings midway between the existing groove marks on the hammer, which is softer felt and therefore quieter. As long as the hammers don't move so far that they are once again lining up with groove marks on the hammer and/or not hitting the left string of the note to its right you're probably good.

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    Geoff Sykes, RPT
    Los Angeles CA
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  • 5.  RE: Grand Piano Hammer to String Alignment

    Registered Piano Technician
    Posted 11 days ago
    Greetings,
       I set the hammers alignment so that on full una-corda the hammer is just barely under the left hand string.  Then, I use a sandpaper file to very lightly lower the crown under that string.  This allows the hammer to barely activate the left hand string, thereby reducing the tendency for that unstuck string to impede the damper lowering. Since a non-vibrating string doesn't assist the wedges from dropping between them as well as the vibrating strings, this results in less twang on a slow pedal release when using the una-corda.  At the same time, the other two strings are being struck with the softer felt that is between the grooves left by normal play, so the una-corda function is a definite change from the normal.

       I believe that the una-corda designation originated when bichords were the norm, and the shift went to one string.  Now that trichords are so common, perhaps the pedal would be more accurately labelled the "bi-chorda" pedal, but I doubt that will gain much traction....
    Regards,

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    Ed Foote RPT
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  • 6.  RE: Grand Piano Hammer to String Alignment

    Registered Piano Technician
    Posted 11 days ago
    This makes a lot of sense Ed. I've gone back and forth on this issue. For a while I really liked to get a "true una chorda" where the 3rd string was missed, because I like the ethereal tone that you can get with this. The downside (as you point out) is that you can get more "oinking" dampers. I look forward to trying your approach - maybe this is the ultimate solution.

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    Ryan Sowers
    Olympia WA
    360-705-4160
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  • 7.  RE: Grand Piano Hammer to String Alignment

    Registered Piano Technician
    Posted 11 days ago
    A piano professot at Alabama would "ride" the shift pedal to get a variety of sounds from the hammer. I had to voice each part of the hammer seperately.

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    Willem "Wim" Blees, RPT
    St. Augustine, FL 32095
    Tnrwim@aol.com
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