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Yamaha C 3 Conservatory Grand Regulation

  • 1.  Yamaha C 3 Conservatory Grand Regulation

    Member
    Posted 21 days ago

    While I was easing the keys on a C3 Yamaha Grand I observed that the drop screws where turned up so high they nearly scrape the pinblock and that all of the letoff buttons where turned up touching the letoff button rail. The piano plays okay but I need to spend some time regulating the entire action. Things I need to check include hammer blow, repetition spring strength, action center friction on rep lever, whip flanges, jacks, key dip and after touch , glide bolt height, back checking, letoff, knuckle shape, jack position under the knuckle. All of the hammers are original Yamaha with very little filing 

    The piano was formerly owned by a teacher and is now in a small Chapel. A full Piano Life Saver was installed July 4th of 2023 and has done extremely well over a very humid summer . 

    Any suggestions on how I can get this instrument back to Yamaha specs will be extremely helpful. The Church has a limited budget so I will have to work with that . I think half a day of regulation will bring great results



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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 2.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 21 days ago
    The first thing I would check is to make sure all 8 action brackets feet are screwed down all the way. It could be that sometime in the past the teacher took off the stack to remove a pencil or coin stuck between the keys, and he didn't get the stack back on all the way. A very easy thing to do if you're not experienced taking action apart. 







  • 3.  RE: Yamaha C 3 Conservatory Grand Regulation

    Member
    Posted 21 days ago

    Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested



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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 4.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 18 days ago

    This caught my eye:  "I followed the Yamaha recommended sequence to putting the screws in"

     I don't think I remember hearing that there was a Yamaha recommended sequence. Mostly what I've heard is not to put in angled screws before the ones that go straight down. Generally I put the screws into the 4 corners first, and then put the rest in. Sometimes I've tightened them like lug nuts, basically jumping around as I tighten in an attempt to get even stress. I'm always wondering how much it really matters. 



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    Ryan Sowers RPT
    Olympia WA
    (360) 480-5648
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  • 5.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 18 days ago
    Angled screws always last. That was Yamaha's first rule. 


    Sent from my iPhone





  • 6.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 17 days ago

    There is always a certain amount of inevitable twist on the keyframe and action frame.

    I have found the best way to get consistent results is to install all the screws in the same order,

    keeping in mind that angled screws will move the action rearward if installed early on. 

    FWIW, it makes sense to me to always follow a routine:

    Back corners,

    Front corners,

    Back row from outside toward center,

    Front row from outside toward center. 

    While it may not make a huge difference, it does ensure that all the frame members twist the

    same way every time, thereby avoiding small differences when things are not done in the same 

    sequence and minimizing any related duplication of effort.



    ------------------------------
    Dave Conte, RPT

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



  • 7.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 17 days ago
    Hi Dave, 

    That is the Yamaha protocol. Several times, after removing the stack and replacing it, I've found the hammer line wildly up in the air! That's because the previous tech started with the angled screws (moving the stack forward, as you said) then they turned the capstans to "correct" the hammer line. 



    Sent from my iPhone





  • 8.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 17 days ago

    Thanks Jim and Dave - great description. This gets me thinking about another issue related to keyframes: what type of surface is the keyframe on when the screws are installed and tightened. In the shop I have workbench space, but in the field its either the LaRoy caddy, or the piano  bench, or the top of the piano. I'm imaging that uneven stresses on the keyframe could also have an effect. Perhaps just a drop cloth on top of the piano would be best so that the entire frame is well supported. So many details to worry about...



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    Ryan Sowers RPT
    Olympia WA
    (360) 480-5648
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  • 9.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 17 days ago
    Ryan,

    I don't think that matters too much, in my experience, as long as it not hog wild. The order is key (i.e. angled last). I should mention that Steinway has a specific order, but basically if you do corners first, as Dave said. Then you've 'locked' the stack into position, and since there are no angled screws the other brackets will sit aligned. Between the Yamaha and Steinway order is where most action are. However...

    I've had some odd actions (older)where all the screws were angled! Maybe someone can remember the make. With that, all I did was put the rear screws in first, then the front, hoping that the hammer line would look as level as it was before. Luckily it was. I'm wondering now if I had done the front ones first if I would have had trouble? I dunno and don't care. (It was a pos. ��)



    Sent from my iPhone





  • 10.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 21 days ago

    Mr. Kelly,

    Hope you are well and happy. It seems that the second sentence of your post is the most telling. With the conditions in the first sentence I'd expect the hammers to be blocking on the strings. Perhaps the hammers have been filed so often that escapement has had to move closer and closer over time. Maybe check the bore distance against the string height minus hammer center height numbers. If the bore distance is very short then returning to Yamaha spec would probably mean new hammers. A lot of Yamahas I've seen had slightly short bore distance and a 2 or 3 degree rake to compensate for over centering. 



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    Karl Roeder
    Pompano Beach FL
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  • 11.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 21 days ago
    James,

    Check the key bedding and glide bolts first, before anything else (not partway down the list). See the Yamaha 37 Steps sequence, if you can get a copy of it. That series is the basis of the Home Office PTG GAR class (Grand Action Regulation in 37 Steps) and of Richard West’s book on regulation. And it originated in the Yamaha facility in Buena Park, home of the Little Red Schoolhouse.

    When new pianos naturally “break in” and age, the soft parts compress (back rail cloth, capstan cushions, knuckles etc.) and the hammer line sinks, making aftertouch thin to nonexistent. I have seen poorly informed technicians regain aftertouch by cranking the glide bolts down too far, to the extent the action is being pushed upward, making for all sort of very confusing issues.

    Making sure the rails and glide bolts are well bedded is an early step in the process, and some other odd things may resolve on their own if that was a big problem.

    Good luck,

    Kathy




  • 12.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 17 days ago

    Good points all esp. Kathy's regarding the glide bolts.  

    I have "rescued" several technicians who have called me to find out why the action they were working on didn't work after R/R the action stack.  "It worked OK before I took it apart"!!  In those cases it was the angled screws holding the front of the stack up off of the key frame.  Like Jim's scenario above with the angled screws front AND back simply holding the stack in place or even a clamp might help to get the stack "seated" so that the threads of the screws are not holding it above the action frame.  It's actually really, really solid when properly bedded.  

    Also, I can't tell you how many action stacks I have simply screwed down that were loose and conquered a whole world of issues previously present.  Things like lost motion, hammer tails catching on back checks and even sluggish repetition springs (they weren't being compressed enough) not to mention all the clicky-ticky noises as a result.  

    Mike 



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    Michael Reiter RPT
    Eugene OR
    (541) 515-6499
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  • 13.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 17 days ago

    One other thought BTW.  How about checking the action spread?  Could it have been altered at some point.  Might explain a bunch, particularly with regard to the let off buttons.

    Mike



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    Michael Reiter RPT
    Eugene OR
    (541) 515-6499
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  • 14.  RE: Yamaha C 3 Conservatory Grand Regulation

    Member
    Posted 15 days ago

    Michael   ... what should the action spread be for this action ? I have replaced several sets of action brackets on Young Chang pianos including other pianos that had expanding brackets. I would have to look at the instructions I have that came with the replacements. 



    ------------------------------
    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
    ------------------------------



  • 15.  RE: Yamaha C 3 Conservatory Grand Regulation

    Registered Piano Technician
    Posted 15 days ago

    James

    The number I have always used for Yamaha and I believe it correct is 112.5 mm.  It hasn't failed me yet but this assumes that you are working with original parts.  If they have been changed for third party parts it may be different.  As always you will want to check not only the spread but also the jack to knuckle alignment--the back of the knuckle molding and the back of the jack need to be in the same plane with the jack aligned with the back of the knuckle molding.  You should not see an angle between the two.  Some actions may require a bit of adjustment to that number but never more than .5 mm.  The biggest clue for me was the let off buttons not in the right place and drop screws out of whack.  Again assuming that the parts are correct, the knuckles are not flat as pancakes and properly bored hammers.  You might also have a look at the string height vs. boring distance, vs. hammer center height.  I usually make a "story stick" out of those handy dandy sticks that used to come in the Renner hammer shank boxes.  They are 1/8"x 1/2" (2x12mm~) and placed on the keybed to measure the string height at various points, treble and bass.  Just make a pencil scribe from under the strings and be sure to take two in the bass to allow for the added diameter of the low bass strings.  Use the same stick to measure the hammer center pin height.  You can then put a hammer shank assembly over the marks and get a quick idea about the boring distance of the hammers.  Details can be garnered from some additional measurements.  I have used this method for years to determine the boring distance for my hammer installs with great results.  

    BTW where are the hammer shanks with respect to the hammer rest felt?

    Mike



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    Michael Reiter RPT
    Eugene OR
    (541) 515-6499
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