[pianotech] Scary Experience

[Tom Driscoll]

Matt,
    My first job  after piano tuning school was as store technician  for a Baldwin dealer . This was 1979 and many of the grands demonstrated this same problem throughout the block ,not just one section . How old and what model would be helpful here.
    There was an article in the journal around that time describing friction issues between the tuning pin and block.
(Help me out crew if I get this wrong ) Static friction and  moving friction are in play .Overcoming static friction gets the pin moving .If the friction resisting continued rotation of the pin (moving friction) is too low in relation to the static friction the pin jumps as you describe.
Back and forth I would go until maybe it would end up somewhere near my target. Not a recipe for tuning stability!
The word in the trade  was "Baldwins are pinned too tight" and from the manufacturer "They are tight now so they will be perfect when they settle down" 
As to your assumption about the rust I doubt that is causing this symptom. I would lube with protek or Goose juice in any case.
Pinblock contamination with some type of lube could cause this
or it could  also be a design issue . Our illustrious designers here on list will modify  the relationships from the capo to the pin as they are able for smoother tunability.
Whatever the cause after more experience you may find a lever technique to make tuning easier on this thing. Also it is very unlikely that the snap - jump of the pin will pull the string sharp enough to break.
 You could possibly experiment with a ream-and repin with a 3/0 pin on the worst one .  It may work but  it's a potentially hard sell for a client to accept .
"You want me to spend $ XXX so you will have an easier time tuning my piano? Mr.,Ms. Tuner who used to tune it never mentioned this"
    I will look forward to some more input from the rest of Newtonville.
Best wishes Matthew,
Tom Driscoll RPT
  -age ----- 
  From: Matthew Todd 
  To: pianotech at ptg.org 
  Sent: Saturday, December 06, 2008 9:59 PM
  Subject: [pianotech] Scary Experience


        So today I tuned a Baldwin grand that had rusty strings.  The rust wasn't throughout the strings just in splotches along each string.  When I got to the high treble I could not control the movement of the pitch as I was tuning and that was one of the worst feelings!  When I wanted to turn the hammer a little bit, I heard a loud 'snap' and the pitch got away from me and went way sharp.  I am assuming this is due the capo bar binding on the strings due to the rust?  Anyway, what is the best approach to this type of situation?  I am almost ashamed to say, but that tuning today was at best, second rate, only because I was kind of nervous about not having control of what I was doing and possible string breakage.

        Thank you,


        TODD PIANO WORKS 
        Matthew Todd, Piano Technician 
        (979) 248-9578
        http://www.toddpianoworks.com 



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