Received a call for help from a non-PTG individual who has done some tuning and tunes their own piano. This U3 is their own piano not one of their customer's.
The problem is that particularly in the top section starting above the tenor they experience tuning instability such that while they are tuning as they check lower notes, many of those notes have deviated from being in tune.
Tuning pins are adequately tight; Bearing points have been lubed. Piano nominally at pitch. Positive general integrity of soundboard and bridges. Piano not being moved.
Since this occurs during the tuning process, seasonal humidity fluctuations are irrelevant.
What I'm wondering is if there is anyone who has experienced/observed a similar situation and if so if you determined a cause.
Also I'm wondering about the actual design structure of the piano. Almost all vertical pianos do not have a plate flange for the pinblock. Is that the case here? Any other design/construction details that could be of interest?
I want to be as equipped as possible prior to my visit to that piano, so all comments welcome.
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Keith Akins RPT
Menominee MI
(715) 775-0022
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