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Adjusting Yamaha grand action glides

  • 1.  Adjusting Yamaha grand action glides

    Posted 02-28-2018 19:23
    I recently had an interesting discussion with Greg Frank at Yamaha regarding the proper bedding of the balance rail. I'd like to do a poll of members here.

    I remember being taught that the guides should not be used to achieve proper key dip. But, are there times when it is appropriate to turn the glides down to raise the key height, thus getting more dip and aftertouch?

    I'm curious what folks on this list think. Would I be violating good regulation procedure if I used the action glides on a new C3 to get the proper key dip, or is it best practice to always adjust the glides so they don't affect key dip?

    Thanks for helping with this question!

    Ryan

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    Ryan Sowers
    Olympia WA
    360-705-4160
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  • 2.  RE: Adjusting Yamaha grand action glides

    Posted 02-28-2018 20:05
    Well, evidently it’s Yamaha’s acceptable procedure for relatively new pianos BUT I don’t do it.

    Sent from my iPhone




  • 3.  RE: Adjusting Yamaha grand action glides

    Posted 02-28-2018 20:15
    Edited by Ed Sutton 03-01-2018 06:09
    The keyframes of Yamaha pianos are flexible enough to allow a degree of adjustment of key height (and therefore dip) by turning the glides down a little. This might be appropriate, for example, when a visiting performer wants a bit more aftertouch in an already well-regulated concert piano.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 4.  RE: Adjusting Yamaha grand action glides

    Posted 02-28-2018 22:23
    There a some Yamaha grands which use mild steel for the keyframe slats. These keyframe must have the support of the glides to set key height. If you raise them all the way up, the keys will have no dip.

    The typical Steinway style keyframe is best bedded at the backrail first, then the front rail, with the studs left raised above contact with the keybed until the complete action is regulated. If you try to use the studs for raising the key height, the front rail and back rail will no longer be bedded. Studs are set just before you put the prop rail in and before you make, install and regulate the dampers.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 5.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 11:42
    Thanks for the discussion, guys.

    After going through the Steinway and Shigeru Kawai trainings I got into the habit of checking action glides a lot. I bought the WNG tool, which makes it very easy. A number of manufacturers warn technicians against using the glides to affect key height. However, after talking with Greg Frank and re-reading my 37 steps book I realized that Yamaha's approach is different.

    Greg said that in the factory they set the glides at 2 mm below the balance rail and then level the keys. I ran into a problem with a few Yamaha pianos trying to adjust the glides as I would in a Kawai or Steinway. I created more work for myself by having to add more card punchings under the balance rail felt punchings to get the key height back up to get proper aftertouch.

    Just a reminder to "know thy piano", and that an approach used by other manufacturers is not necessarily appropriate for all.

    Cheers!

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    Ryan Sowers
    Olympia WA
    360-705-4160
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  • 6.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 12:15
    Ryan,

    Yamaha teaches that in a well regulated piano, the glides should be adjusted to achieve proper key height.

    Steinway called their glide adjustments "TR" screws for "Touch Regulating".

    I use the WNG keyed regulating tool and turn down the glides by .002 - .004 to restore more aftertouch on an action after a few years of playing.  That number doubles the effect at the key, making more dip and more aftertouch.





  • 7.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 13:03
    I just spent four days at Yamaha HQ taking the Performance Piano Seminar, and for new or almost new Yamaha pianos using the glide bolts to make fine adjustments for key dip where required is exactly what we were instructed and trained in doing. The presumption is that the keys are already at the correct height from the keyed and level, and the rest of the regulation is already pretty close. We fully bedded the key frame, then in a few areas where the key dip was a touch shallow we turned the glides down just a touch and checked until key dip was even with other sections. If this meant you could get a little bit of a knock retesting that section that was acceptable.

    As we were told repeatedly, this procedure was advised for relatively new Yamaha grands only; they offered no opinion or suggestion as to whether the procedure might be useful or applicable to any other piano.

    We got pretty great results!

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    David Trasoff
    Professional Piano Service
    Los Angeles, CA
    323-255-7783
    david@professionalpianoservice.com
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  • 8.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 14:56
    I believe I mentioned this in my regulating series in the Journal a couple of years ago.  At least, I mention it in the regulating classes I have taught.

    Anyway, the fundamental issue here is for us to mature from using specifications to using parameters. We inherit  specifications from what factory workers are told to do to make the piano work so it can be shipped. A specification says "do this" and doesn't explain what the issues are. Parameters give us the "ditch on either side of the road" so we can then navigate as we see fit -- whether that is pulling out to pass another car or pulling over to the right to make way for an oncoming oversize load.

    In the case of the key frame, I believe they should be set from scratch the way(s) we have been taught. But keyframes are all flexible and we can take advantage of that flex. Parameters tell us how far we can go before something bad happens. Specifically in this situation, the guides can't go so far down as to lift either the front rail (or perhaps the back rail) off the keybed. Conversely, they can't be so high as to knock (or simply just allow the balance rail to flex) when the key is played. (Perhaps, when the key is played when one or more pedals are being depressed.)

    So, between those two parameters, nothing bad will happen. You CAN use the guides to make small changes in key travel.
    Really.
    Even if you have been told "never use the glide bolts to adjust key travel".
    And you don't have to feel guilty about doing substandard work.

    As our craft matures, we need to question dictums like that so that we understand the principles behind them. When we understand principles we will know the appropriate parameters and have greater freedom to provide service appropriate to the situation.

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    Keith Akins
    Akins Pianocraft
    Menominee MI
    715-775-0022
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  • 9.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 15:44
    "As our craft matures, we need to question dictums like that so that we understand the principles behind them. When we understand principles we will know the appropriate parameters and have greater freedom to provide service appropriate to the situation." -  Keith Akins

    I like that! Seems to me that this is also called, common sense. 😉


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    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure, TuneLab & Easy Piano Tuner user
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  • 10.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 16:59
    Yes, well said Keith.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 11.  RE: Adjusting Yamaha grand action glides

    Posted 03-01-2018 19:04
    Dunno why I put "guides" instead of "glides".  Anyway, I meant "glides".

    I also wanted to emphasize that sometimes using the glides to make minor adjustments to key travel is absolutely the better and preferred thing to do. That approach will cause much less chaos, trauma and instability than tearing of the top stack, pulling off all the keys and then reversing the procedure just to put a blue punching on each of the balance pins.

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    Keith Akins
    Akins Pianocraft
    Menominee MI
    715-775-0022
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  • 12.  RE: Adjusting Yamaha grand action glides

    Posted 03-02-2018 14:53
    Actually it's not as bad as you might think. The important thing is to mark all the balance rail felt punchings with a pencil dot at the 6 O'clock position. It's remarkable what a difference it makes to keep all the punchings oriented in the same direction. The predictability and stability is fine if you don't change the position of the felt.

    Yamaha's main argument is that they want to maintain the key height (measured from the keybed to the underside of the white key covering) to factory spec (66 mm on the concert grand and 64 on the other grands). This keeps the leverage consistent. Raising the key height pivots the capstan towards the backside of the wippen, slightly increasing the action ration - which theoretically is going to make the action a little heavier.

    So if there is not enough key dip with the proper key height, Yamaha prefers the action glides to lift the keys to the point where proper aftertouch can be achieved. The glides can raise the keys and not affect the action ratio.

    I haven't measured it, though. I'm curious how much the action ratio changes with a 1 mm increase in key height. I'm skeptical that it is significant, but it would be interesting to to take a down weight measurement before and after adding a blue punching under the balance rail.

    The upside of the Steinway and Kawai approach is that it is very quick and easy to make fine corrections to the system once it is set up properly. The Yamaha system seems more "nebulous" and more challenging to create consistent pressure on all of the glides. On the other hand, perhaps the Yamaha system is lest apt to knock during humidity changes.


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    Ryan Sowers
    Olympia WA
    360-705-4160
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  • 13.  RE: Adjusting Yamaha grand action glides

    Posted 03-03-2018 08:13
    All I know is that a good pianist can feel it when it is out (though they don't know what it is)...actually they feel it once you correct it without their knowledge.

    I have a client with a Bosendorfer 225 from the 70's. It has no balance rail glides. The balance rail is not fully in contact with the keybed.  I have long wanted to install some glides but he is happy with the way it is. He plays at concert level. Go figure.

    Pwg

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