[CAUT] Key bottoms

[Barbara Richmond]

Mark,

Thank you, that's good to hear.  I'm headed down to the shop to get started on this B--whose owner doesn't use AC.  The keys are a mess, but mostly due to someone else's work, I think.  It will be interesting to see how they respond.

My best to Floyd--and you, too, of course!

Barbara
  ----- Original Message ----- 
  From: Mark Cramer 
  To: College and University Technicians 
  Sent: Friday, July 27, 2007 11:59 AM
  Subject: Re: [CAUT] Key bottoms


  Hi Barbara,

  we had an older Yamaha G-2 with balance-holes ovaled fore & aft to nearly twice the size of the rail pin. (!?)

  Some keys literally had an 1/8th inch of pulley, making it difficult in some cases to determine where the original hole-center was. 

  Obviously this isn't normal wear and tear. ( I'm guessing someone forgot to read the fine print on their new easing tool) 

  Nonetheless, we used Bill's method (PT Journal; May 1990) during the course of rebuilding the action; fall of 2005,  and the keys continue to fit and work beautifully.

  There was a fair amount of alignment needed with the initial fitting, but I'm guessing this was more my inexperience than the method itself.

  best regards,
  Mark Cramer,
  Brandon University

  PS Floyd is back here in Manitoba, Barbara. He's just applied for membership to the MB Chapter, and is helping access/repair vertical practice pianos. He's intent on completing the exam series, and I'm glad to have his help in the shop.






    I can see that this method would be better and more stable than squishing wood.  Is there anyone with experience with it from the Far North, Midwest or Northeast where we go through <huge> seasonal swings in humidity levels?

    Thanks.

    Barbara Richmond
    on the way out the door to pick up a S&S B action w/key bottom trouble


      ----- Original Message ----- 
      From: Keith Roberts 
      To: College and University Technicians 
      Sent: Thursday, July 26, 2007 10:14 PM
      Subject: Re: [CAUT] Key bottoms (was Re: key-easing pliers?)


      When I replaced the balance rail holes ala Spurlock, I drilled them slightly smaller the first pass and they were tight, really close. I took a 1/8" chainsaw file that mics at .130 to .135 on the cutting surface and it was tight so I inserted the file in the hole and rotated 1 turn counterclockwise and removed. (I had to make a handle). They were perfect on the new pins. 
      Lucky me.
      So I ground off the back and sides of one of those files till I could taper the hole until the key rocked nicely and leave the bottom untouched.

      And when I checked them 2 years later they are still perfect. 

      Keith Roberts

       
      On 7/26/07, Fred Sturm <fssturm at unm.edu> wrote: 
        On Jul 26, 2007, at 11:46 AM, Jim Busby wrote:
          Fred,

          One difference/question I have is - isn't it easier to insert the proper sizing cauls, then turn the set upside down and insert the BR pins (the cauls won't let the pins fall through), then add sizing fluid? After they dry, ream the mortise so the "foot" of the hole is the exact thickness. 


        Takes a long time to insert those balance pins in each hole, and then pull them out later (I don't have a bunch of student helpers, so a few seconds here and there on each little procedure add up). I'm "reaming" with a drill bit, which doesn't remove as much wood as a real reamer, and maybe leaves a bit of "uncut splinters" (we're talking fairly microscopic) to hold glue if I need to size later. That's my reasoning, anyway. And I think it leaves a more stable condition than just putting in BR pins and letting the wood conform to them, if your holes are too small to begin with. I'm closer to having the right amount of wood (in this dimension, not to be confused with the reaming you are talking about above). Making the hole exactly the size of the pin will require a bit of easing. So I use one sizing caul, which is heated. The heat increases the size of the balance pin in the caul from .146" to .147", and the heat helps size the wood - make the size relatively permanent. It puts the hole .001" larger than the pin, very nicely and consistently. (Glue-sizing to make the hole smaller where needed is a separate part of the procedure, done only to holes that are too large). 

          Replace them on the Keyframe to check BR fit and fix pulley keys. 


        That's a lot of time and work. I like to leave the keys in the clamp, and bring the balance pin to the key. I can feel that pin going into the hole very precisely, and also feel if there is any play in any direction.. 

          Many times pulley keys are no longer an issue with the glue sizing formula. BTW I use a much diluted (12/1 or so) Elmer's glue for sizing. Ron N. tells me that this is the only place on a piano where he uses that glue. (Thanks Ron) There is no sound, click, etc. with Elmer's glue as there is with PVCE, Hot Hide, and or other glues. 



          Baldassin taught me to add this extra step (it really doesn't take long) of placing the keys back on the frame BEFORE the bushings are in so that you can work the BR holes w/o "false readings" from overly tight new bushings. It takes about 10 – 15 minutes longer but the total focus on the BR hole pays big dividends, IMO. Here is when I deal with the pulley keys because now you're sure of which ones weren't fixed by the glue sizing. 

        Rick B is certainly correct in wanting to separate bottom hole from bushings, so one doesn't mask the other. I think I do it with a lot less time and effort. Putting a loose pin into the hole removes the factor of the weight of the key. All that lead can mask a lot of problems. 
          Anyway, just a bit more to consider for your book... Who knows? Marriott's success, he said, was to "write out every tiny process and revise it in writing until nothing more could be perfected, then get all your employees to do it THAT way." 

        I don't like having employees other than myself. That's one reason I am in this business <G>.  
          (I vote for you to write that book, sometime before your beard is entirely gray?? You and Ron. Oh well, Ron…)) 

        I don't think there's much chance of me compiling and writing in book form. But if anyone else wants to do that, and make use of what I have posted from time to time, that would be fine with me. Have at it with my compliments. 
          High regards, 

          Jim

        Regards,
         
        Fred

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