Pianotech

  • 1.  new to damper systems

    Posted 12-05-2019 12:23
    Learning piano technology is a lot like learning to drive: you learn the basics, then every time you get behind the wheel, for the first year or so, you encounter stuff your driver's ed teacher never told you.

    Most of my training has been through videos, which I would watch and then go over to my own Yamaha upright and try to figure out what in my piano matched what in the video.

    I've seen several videos explaining how to bend the shaft that holds the damper in place. It is always emphasized that you have to make TWO bends, one to shift the shaft and the other to shift it back.

    I always assumed this meant something important, but my Yamaha upright has damper SHAFTS that are STRAIGHT up and down.

    Since this is the only piano I have taken apart over and over again, I had no experience of the system that uses bent wires for angling the dampers.

    It's a little like learning to drive on an automatic, then suddenly your friend lends you his car but it turns out to be a shift!

    How does my Yamaha manage to angle the dampers so that the bass dampers are angled to the left, and the mid range to the right?

    The dampers are actually GLUED on at an angle to a dowl-and-screw mechanism that itself plumb on the damper wire, with each actual damper glued at an angle to match the slope of the strings--sharply to the left for the bass notes, less sharply to the right for notes after the first strut, those dampers gradually straightening out until by the second strut the strings themselves are short enough that they do not have to be angled at all.

    Now, this is a great way to set things up, but replacing an entire damper means calculating (or visually measuring) the exact angle of the damper to the block. Then you have to actually glue it with old fashioned water soluble glue and try to keep the whole assemblage clamped in exactly that position until the glue dries.

    Gluing the dowel part of the damper block while it is still in the piano and then pressing it very hard against damper assembly, which you have already placed touching the string(s) does not work for a number of reasons, not the lest of which is that the pressure needed to hold the it in place would damage the string or the damper wire or the sanity of the piano technician.

    I still do not have functioning dampers for three or four mid range notes.

    Advice?

    Hank Mooney
    San Francisco
    granjon@sonic.net
    (email advice if any... I never actually answer my phone)

















    ------------------------------
    Hank Mooney
    San Francisco CA
    415-640-2731
    [Hank]
    ------------------------------


  • 2.  RE: new to damper systems

    Registered Piano Technician
    Posted 12-05-2019 13:18
    Gluing the dowel part of the damper block while it is still in the piano and then pressing it very hard against damper assembly, which you have already placed touching the string(s) does not work for a number of reasons, not the lest of which is that the pressure needed to hold the it in place would damage the string or the damper wire or the sanity of the piano technician. I still do not have functioning dampers for three or four mid range notes. Advice? Hank Mooney

    Hank

    Gluing the dampers in the piano as you describe is exactly the way it's done. With a finger pull the damper wire, which you call the shaft, away from the string, and put the damper block onto the wire. Slide it down on the wire to the same height as the others, and tighten the screw. Then add the damper felt, with a drop of glue where it will be in contact with the block of wood. You don't have to press the dowel against the string because the pressure of damper spring against the strings is enough to keep the damper in place. Obviously you need to give it some time, (at least 10 minutes), to allow the glue to set up. 

    By doing it this way, the damper felt automatically seats itself on the strings. 


    ------------------------------
    Willem "Wim" Blees, RPT
    Mililani, HI 96789
    ------------------------------



  • 3.  RE: new to damper systems

    Member
    Posted 12-05-2019 14:36
    You align the dowel over the center of the unisons and space evenly before gluing. That's the only side bending you do. Then you adjust all the dampers to lift at the same time by bending the wire at the low point forwards or back and then re angling the head to be flat to the string. Find a few dampers that are lifting at the correct spot in the key stroke  and match the lift on those or determine which way of bending brings the spoons into better regulation. Then after all dampers lift evenly, bend the spoons so they lift at the proper point in the keystroke.
    Easy right? Not,,,. Damper regulation is what most techs avoid,,,,,

    ------------------------------
    Keith Roberts
    owner
    Hathaway Pines CA
    209-770-4312
    ------------------------------