[pianotech] found it was hammer return noise

[Gene Nelson]

  ----- Original Message ----- 
  From: Ed Foote 
  To: pianotech at ptg.org 
  Sent: Monday, March 01, 2010 5:55 AM
  Subject: Re: [pianotech] hammer return noise


      I find that having the rep lever height set so the jack and knuckle are well acquainted with one another, will often quieten the return noise.  See if it is quieter with a significant "wink" in place.  
  Good luck, 
  Ed Foote RPT

  ***For anyone who helped with all of your great suggestions, thank you so much.
  I have tried everything (I really mean everything) that was suggested for everyone who has responded to my plea for help.
  The answer was in Ed Foote's suggestion.
  After all was tried and failed, hard knuckles, loose centers, loose screws and glue joints, excessively hard under key felt, too strong rep spring tension, poking holes in things, remove stack and bang on keys - etc etc, all  were eliminated, except----.
  The clue was that I was getting some results whenever I did anything to the jack position so this became my focus.  I went through the jack knuckle alignment much more carefully, slightly rounded off the far edge of the jack tops, and then sat down and carefully adjusted the rep lever height. Bingo, when the height was greater than I would normally choose to set it and the jack returns ok but it looks like the breaks are just being put on - this is when the woody clunk disappeared. Actually it is such a specific point where this happens I can regulate rep lever height till the clunk stops and the regulation is correct.
  Thanks again everyone, it was a grand exercise and I really learned something.
  Now if someone that knows why this happens I would love to hear the explaination.
  Regards,
  Gene

















  Key frame is properly bedded.
  Action is regulated.
  All action frame joints and screws are solid and tight.
  All action parts screws are tight.
  All centers are at optimal friction with no wobble.
  All hammer glue joints are solid.
  All whippen glue joints are solid.
  Hammer rest rail has new felt, is adjusted at correct height and nuts are tight.
  Key stop rail has new felt and is adjusted for minimal up key movement.
  I have checked the knuckles - the core is firm dense felt and a needle easily goes in from the side. Buckskin is not too tight over cores.
  I have had minimal to zero results using my sugar coater on the knuckle buck skin.
  I can depress the key about 2mm, release it and give a slightly woody clunk upon return. 
  Noise is a bit louder when hammer falls after releasing from check.
  Happens on the bench and when secured in the action cavity.
  It is noticeable when playing especially in the upper treble section with lid closed but the noise exists in the lower parts as well but not quite so noticeable when playing.

  Any ideas would be helpful.
  At some point I should just give up and accept it as normal action noise? 
  Thanks for your thoughts.
  Gene

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