Pianotech

  • 1.  45 sostenuto

    Registered Piano Technician
    Posted 03-05-2025 08:17

    I'm trying to adjust the sostenuto rail on a 45 S&S studio. I can't figure out which direction the rail has to go to make it work properly, specifically in the upper two octaves. 

    When I was first called to look at the piano, a couple of dampers in the upper treble were hanging up on the tab. I solved that problem by slightly tapping down the rail. But the problem I'm trying to solve is when the sostenuto pedal is pressed, about half a dozen dampers are hanging up on the rail. It seemed that no matter how much I taped down the rail, the dampers were still hanging up. I took the action out and saw that the rail takes a detour around the treble strut. I'm not sure if that is what keeps the rail from working properly. 

    I could use some guidance on this. It's the first time I've encountered a 45 with a sostenuto. 

    Wim



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    Willem "Wim" Blees, RPT
    St. Augustine, FL 32095
    Tnrwim@aol.com
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  • 2.  RE: 45 sostenuto

    Registered Piano Technician
    Posted 03-05-2025 08:32

    Wim,

    I recently had a similar problem on a 45. It became clear that it was going to eat up a lot of time.  Ultimately I simply deactivated it (nobody uses it anyway) and told the client that unless it was truly necessary it was not going to be worth the cost to correct it. (She didn't even know what it does).

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 3.  RE: 45 sostenuto

    Registered Piano Technician
    Posted 03-05-2025 09:14
    Peter.

    The student who is playing the piano is 6 years old with one year of lessons. He doesn’t know what the middle pedal does, either, but his mom insists that the piano does everything it’s supposed to. Sigh.

    Sent from my iPhone


    Original Message


  • 4.  RE: 45 sostenuto

    Registered Piano Technician
    Posted 03-05-2025 09:06

    Hi Wim,

    This is outlined in the Steinway & Sons World Wide Technical Reference Guide, but my advice on the topic is below.

    Proper regulation of the sostenuto requires properly regulated dampers and sostenuto tabs in a relatively straight line.

    The correct resting rotational position of the sostenuto blade should be set up so the tip of the blade is at the same height as the round body of the sostenuto blade/cross-rod assembly.

    (In other words, you should be able to lay a ruler front to back across the blade and body, and it should be parallel with the floor.)

    The correct position of the blade from the tabs is 1/16" below, and 1/16" away from the line of sostenuto tabs on the dampers.

    The blade should rotate enough to engage the tab that is lifted and prevent other dampers from slipping through.  Check for over rotation that the dampers are not burying deep in the damper stop rail.

    Last, engage the sustain and then engage the sostenuto and slowly release the sostenuto and make sure the dampers fall in all sections at random and watch out for dampers that cascade section by section.

    A very useful tool for all sostenuto regulation is the "Streamlight Stylus Reach" https://www.streamlight.com/products/detail/stylus-reach

    This flashlight allows you to get light behind the tabs and blade and be able to see very clearly the distance between the two.

    Feel free to reach out directly if you have any questions.



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    Daniel DeBiasio
    Technical Education & Support
    ddebiasio@steinway.com
    718-267-3229
    Steinway & Sons
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  • 5.  RE: 45 sostenuto

    Registered Piano Technician
    Posted 03-18-2025 16:26
    With the help from Daniel and Norm, I was able to solve the sostenuto problem on the S&S 45 piano. I followed all the instructions, but then I found the real reason why it wasn't working right. The problem was the third bracket was loose from the case, which was the reason it kept working one time, but not the second time. Next time I'll check that first. (If there ever will be a second time). lol 

    Wim



    Original Message


  • 6.  RE: 45 sostenuto

    Registered Piano Technician
    Posted 03-19-2025 07:36

     I am having a related experience with a number of K52s, in which the sost lift wires have been hanging up on adjacent damper levers, especially in the bass. The pianos are all about 15 years old. It was not difficult to correct, but this came on for the first time over the winter. I have been here for 4 winters without this occurring. Nothing was loose or apparently shifted, but it was quite obvious when I was performing routine tuning. Maybe humidity played a factor? Doubtful since we have such effective humidity control equipment.  can't understand why that would be enough to change the physical alignment of the wires or levers anyway. Has anyone else experienced this phenomenon?



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    Dave Conte, RPT

    Piano Technician in Residence
    The University of Tennessee
    College of Music
    Knoxville TN
    (817) 307-5656
    Owner: Rocky Top Piano
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    Original Message