[pianotech] Advice about intermittent note on Yamaha grand

[David Ilvedson]

Hire a tech.

David Ilvedson
Pacifica, CA

On Feb 13, 2010, at 11:38 AM, "Dean May" <deanmay at pianorebuilders.com> wrote:

Hi Robert

It sounds to me like there is a friction problem in one of the action
centers, likely the jack center. If you depress the heel of the jack, make
sure it is resetting quickly to a rest position similar to the other jacks.
If it is a little slow then there's your problem. 

Dean

Dean W May                (812) 235-5272

PianoRebuilders.com    (888) DEAN-MAY

Terre Haute IN 47802


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of rsfinley at charter.net
Sent: Saturday, February 13, 2010 1:58 PM
To: pianotech at ptg.org
Subject: [pianotech] Advice about intermittent note on Yamaha grand

I have been having a problem with one of the keys, C6, on my Yamaha baby
grand piano. The note sometmes sounds and sometimes doesn't. If I play the
note repeatedly, quickly, it sometimes stops sounding. If I give it a rest
and then play it, it usually sounds again. When it stops sounding, the
hammer is not propelled as far as the string. 

I took the action out to inspect it and to compare it with the action of the
surrounding keys. It seems that when the note is played, the tip of the jack
doesn't protrude through the slot in the repetition lever as much as for the
other keys. I guess the tip of the jack has to stick through the slot a
certain amount to engage the hammer knuckle, in order to thrust the  hammer
towards the string, and it is just on the point of not being far through
enough. 

Please could you suggest what the solution might be? If I turn the Letoff
regulating screw so that the letoff button is lower, I think it might cause
the tip of the jack to stick through the slot in the repetition a a little
further because the jack toe will engage the letoff button punching across a
shorter distance than before, making it more certain that the note will
sound. Would this be the correct thing to adjust or is there another
alternative? (I didn't examine the knuckle to see if it is worn or if there
is a deep groove in it. It seemed to be OK)

Thank you very much for your help. 

Robert Finley