Pianotech

  • 1.  Steinway action spread

    Registered Piano Technician
    Posted 08-16-2024 17:08

    I figured I'd start a new thread here rather than interject it into the other Steinway thread already under way.

    1970 Model L here, accel action. I am measuring an action spread of 113mm bass - 113.5mm treble. The .5mm variation does not concern me. What does concern me is that the data I have for action spread is more like 112mm. Fractionally the spec sheet I have from SS says 4 25/64". 

    Anyone know if there was a change in this spec with Teflon action, which this is (mostly)? What is the history here?  And BTW, the jack/knuckle core relationship is actually at 90°. I'm just puzzled by this seeming discrepancy. 

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 2.  RE: Steinway action spread

    Registered Piano Technician
    Posted 08-17-2024 12:49

    Mr Grey,

    Pre 1984 the action spread was nominally  4.381" or 111.3 mm also known as 4 3/8".

    Post 1984 it changed to 4.395" or 111.6mm also known as 4 25/64".

    I don't recall ever finding one where these distances prevailed. I think the discrepancy may have more to do with the manufacture of the repetition flange and the hammershank flange. The way the rails were soldered in also added a lot of variation.

    The distances you mention don't seem like they would cause much of a problem.



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    Karl Roeder
    Pompano Beach FL
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  • 3.  RE: Steinway action spread

    Registered Piano Technician
    Posted 08-17-2024 14:45

    Karl, 

    Yes  we're talking essentially 1mm. And...it seems to me from what I'm observing at present that if I were to change it to 112 or less (e.g., tilting the whippen flanges) I would actually end up increasing the leverage which would increase the touchweight, etc etc. So I guess...if it ain't broke don't fix it. 

    After I restring it I still have the clear option of replacing shanks and hammers, which if I did, I would use WNG and likely Ronsen. 

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 4.  RE: Steinway action spread

    Registered Piano Technician
    Posted 08-17-2024 15:02

    FWIW The current victim errrrr.. project on my workbench is a model B from 1979. With the original parts (teflon) the spread is112.1 mm. With new Steinway (Renner) parts the spread is 113.3 mm. All in all, not nearly the problem that a bad action ratio mentioned in the other Steinway, thread poses on this one.



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    Karl Roeder
    Pompano Beach FL
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