Pianotech

  • 1.  S&S "B" Bell: bolt tightening philosophy

    Registered Piano Technician
    Posted 09-09-2024 20:19

    It's been a while since I worked on a S&S B. This piano has a bolt going down through the plate in the treble into a "bell-shaped" fixture attached to the rim. 

    So... what is the approach to tightening that bolt after re-installation... 

    • just finger tight?
    • quite tight?
    • just before you fracture the string-frame? ;-)

    --Keith



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    Keith Akins RPT
    Menominee MI
    (715) 775-0022
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  • 2.  RE: S&S "B" Bell: bolt tightening philosophy

    Registered Piano Technician
    Posted 09-09-2024 20:29

    You don't tighten that. 



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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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  • 3.  RE: S&S "B" Bell: bolt tightening philosophy

    Posted 09-09-2024 20:41
    Snug before stringing.




    Original Message


  • 4.  RE: S&S "B" Bell: bolt tightening philosophy

    Registered Piano Technician
    Posted 09-09-2024 21:06

    Sorry, misread, after rebuilding, snug after tightening perimeter bolts, unless you're trying to change the downbearing after the fact. Then, with caution. 



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------

    Original Message


  • 5.  RE: S&S "B" Bell: bolt tightening philosophy

    Posted 09-09-2024 21:44
    Hello,

    The old spec for perimeter bolts used to be 30' pounds.  Timely to check periodically.

    The nose, and similar, bolts _can_ be used for _minute_ adjustments of bearing following restringing/&c. Better to wait to see if that's necessary. Otherwise, a serious "finger tight" is a good place from which to start.

    Kind regards.

    Horace





      Original Message


    Original Message


  • 6.  RE: S&S "B" Bell: bolt tightening philosophy

    Registered Piano Technician
    Posted 09-09-2024 22:33

    You wrote 30 ft/lbs. 

    Is that correct or is it 30 inch/lbs. ?



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    Keith Akins RPT
    Menominee MI
    (715) 775-0022
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    Original Message


  • 7.  RE: S&S "B" Bell: bolt tightening philosophy

    Posted 09-09-2024 22:42
    Foot/pounds, as indicated.




      Original Message


    Original Message


  • 8.  RE: S&S "B" Bell: bolt tightening philosophy

    Registered Piano Technician
    Posted 09-09-2024 22:29

    -



  • 9.  RE: S&S "B" Bell: bolt tightening philosophy

    Registered Piano Technician
    Posted 09-09-2024 22:39

    So.... 

    It helps to understand the purpose of the thing--which I believe is to put torque on the rim. Does anyone know for sure what Steinway was thinking when they designed it? Can you hear any difference in how it is tensioned? It was certainly not intended for use in setting bearing (although, yes, you can use it to make minor adjustments -- but I don't). 

    Thanks for the replies so far.

    ------------------------------
    Keith Akins RPT
    Menominee MI
    (715) 775-0022
    ------------------------------



  • 10.  RE: S&S "B" Bell: bolt tightening philosophy

    Posted 09-09-2024 22:49
    It's ostensible purpose if/as to replace a beam that Steinway removed early on as part of a cost-reduction process. The device that Bob Grijalva developed was to (partly) replace the reduction in structural strength in the frame/rim structure that was created by the removal of the beam.

    Bill Garlick had quite a series of slides/transparencies on these kinds of changes. I'm not sure where they wound up.

    Also, Chris Robinson used to teach on these things.

    Kind regards.

    Horace




      Original Message


    Original Message