Pinblock Fit

[David Renaud]

I also know of a Yamaha C7, I could fold by business card
in half and slide in the gap along the full length of the flange.
Never seen quite a gap. Seemed to tune very well until one day
I had to raise the pitch somewhat, felt like it was shifting
in an unusual way.
                                                   David Renaud.

Stan Kroeker wrote:

> Greetings from the rapidly thawing Canadian prairie!
>
> Further to the discussion on pinblock fitting, could someone comment on
> Yamaha's official position on this issue?  A colleague of mine has a client
> whose C3 has a gap between block and flange tapering from 33 thou in the
> bass to about 11 thou in the treble.  The piano apparently suffers from
> tuning instability despite proper humidity control (Dampp Chaser) and
> frequent tuning.
>
> When brought to Yamaha's attention, the official factory response was that
> the gap was "within tolerance".  Is there such a tolerance for pinblock
> fit?  To me, it either contacts the flange or it doesn't.
>
> Regards to all,
>
> Stan Kroeker
> Registered Piano Technician