Pianotech

  • 1.  Wrong strike point? HELP....

    Posted 05-19-2018 11:54

    Hello,

    I'm changing the hammers to a Schimmel grand piano t208. I believe that the sound too annoying (and with little precise harmonics) on some keys of the most acute part of the piano (precisely, from the 77 to 83) is caused by a wrong strike point.
    In fact, as soon as I glued and voiced the new hammers (Renner by Schimmel), I followed the old strike point (the piano as already been regenerated by someone), I realized that the problem remained ....

    How could I calculate the correct strike point?

    I would be tempted to follow my instincts, listen to how they sound and glue them a couple of millimeters closer to the whippen (because, if I move all the mechanics, from the right, a little further, the keys from 84 to 88  become aphonic) .

    I apologize in advance if I have made mistakes in writing or translation, I am Italian.



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    Mario Bianchi
    Roma
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  • 2.  RE: Wrong strike point? HELP....

    Posted 05-19-2018 12:26
    I got these treble Strike point ratios from Ed Mcmorrow. They have been working well for me without glueing and moving treble hammers, which I find fraught with misleading results.

    88- SL/.064, 83- SL/.075, 78- SL/.085, 73- SL/.089, 68- SL/.094, 63-SL/.099

    Measure the as-built Speaking Length(SL) using a thin 150mm Stainless steel pocket rule. I grind the rule down at the end, close to a knife edge, to slip as close to the termination point as possible.

    Cut paper the strike point distance you calculated. Snug it up against the capo, sitting on top of the unison. Mark the hammer top dead center. Raise the hammer to strike, confirm the actual strike center on the hammer as it hits the strings. Adjust mark if the hammer is not striking at top dead center. Move hammer until the empirical strike point is lined up with the piece of dimensioned paper.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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    Original Message


  • 3.  RE: Wrong strike point? HELP....

    Registered Piano Technician
    Posted 05-19-2018 14:25
    Wow.... I was just taught to move the hammers around until they sound good! No scientific method involved. One would just have to know what good tone is supposed to sound like. After determining where the strike point should be, one would either tighten the screw (if it was that type of s/f), or mark the shank with a pencil, then glue the hammer. But I'm going to give these numbers a try next time!

    Mario, as far as your English goes, I wish my Italian was that good!

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    Benjamin Sanchez
    Professional Piano Services
    (805)315-8050
    www.professional-piano-services.com
    BenPianoPro@comcast.net
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    Original Message


  • 4.  RE: Wrong strike point? HELP....

    Posted 05-19-2018 14:50
    With the hammers already glued to the shanks, to find the best strike point is easy. Place strips of masking tape on the key bed (going under the frame) at the ends of the treble sections and one in the center of the first treble section. Position the action for the best tone on C8, that is where the action should be (unless you are moving C8 too).

    Place a line on each tape at the edge of the key frame. Move the treble end of the action fore and aft to ascertain the best tone. Place a mark on the tape. Do this for each strip. The difference in the marks will be the distance the hammers have to be rehung.

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    Regards,

    Jon Page
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    Original Message


  • 5.  RE: Wrong strike point? HELP....

    Registered Piano Technician
    Posted 05-19-2018 16:07
    I acquired a handy strike point gauge from WNG that establishes the (generally) ideal strike point for note 88, and then note 72. 

    I basically use it as a starting point to determine by ear the truly ideal strike point (if different from the gauge). What I listen for is generally a combination of clarity, power, and sustain all rolled into one.

    However, in general I have found that about 2mm at note 88 is pretty close, and about 8.75mm is pretty close at note 72.  Then the strike line goes from 88 to 72, then 72 to 1.

    In the long run though, best to refine it with a good ear.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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    Original Message


  • 6.  RE: Wrong strike point? HELP....

    Registered Piano Technician
    Posted 05-19-2018 22:47
    The strike point factors Jim posted were derived, refined and tested for many years on many pianos. I developed them because I hear strike point differences better at a distance from the piano, and I can't play the piano and sit across the room from it at the same time. In the treble there is really only one precise point to strike the string and get the best tone. Designers have choices to make regarding the striking proportions in the first 50 notes of the piano.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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    Original Message