[pianotech] Breaking Kawai treble strings

[bergpiano]

Don,

Thanks for the great suggestions. I did shape the hammers with string installation. Could you go into a little more detail about how the regulation would contribute to string breakage. I would assume it invloves changing power and velocity. For the benifit of Paul and myself and perhaps others I think it would be good to look at this a little more precisely.

Thanks
Dan
  ----- Original Message ----- 
  From: Don Mannino 
  To: pianotech at ptg.org 
  Sent: Tuesday, February 22, 2011 10:46 PM
  Subject: Re: [pianotech] Breaking Kawai treble strings


  Daniel,

   

  Did you also shape the hammers?  The hammer shape and the regulation will affect this as well.

   

  But in some cases, people just break strings.  Your assumption that they aren't playing it that hard is not supported by the fact that the strings are breaking - someone there likes the piano, and is working it very hard on a regular basis, I think.

   

  One other trick that can be telling is to raise the one balance rail glide screw at the treble break (near where these pianists tend to break the most strings) all the way up.  This is not usually noticed by the pianist, will not affect the tone or touch at all in softer playing, and it takes away a little of the aggressive impact of the heavy handed pianist.

   

  Unfortunately the strings have now become fatigued again, so no matter what you do they will be breaking.  It is best if the hammer shape and regulation are addressed at the same time as the new wire installation.

   

  Don Mannino

   

  From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of bergpiano
  Sent: Tuesday, February 22, 2011 5:11 AM
  To: pianotech at ptg.org
  Subject: [pianotech] Breaking Kawai treble strings

   

  I have a customer with a Kawai GS-70. After it arrived about three years ago treble strings started to break while playing, about once every 2 to 3 weeks. I talked to Kawai techs and decided to restring the capo section. I used Kawai's stringing chart for decimal wire and sanded the capo to shiny smooth. I also filed the hammers. After a short while strings started to break again every month or two. Now they are breaking about one every 2 to 6 weeks. The breaks have always been at the capo. 

   

  What am I overlooking?

  I would not say the players strike overly hard. It is in a private school. Students and teacher (mostly teacher) have broken wire. Classical music. 

  Could hammer position have a bearing here? Hammers are original.

  Regulation? 

  I need some brainstorming here!

   

  Many thanks,

   

  Daniel Berg RPT
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