Grand Touch

[david at davidandersenpianos.com]

Hey, Ric---check the amount of material at the bottom of the balance rail
hole.  If it's more than 3-4 mm from the bottom of the key upwards, the
keys are binding internally on the balance rail pins, and that's where
your "heaviness" is coming from.  Get a balance hole reamer from Yamaha or
Jurgen at Pianoforte Supply; one little tool can make you a superhero. If
that's not it, check the action spread; the "magic line" compliance of
capstan and whippen heel.

Hope this helps....

David Andersen




> If your "48g (easy) downweight and 28g up" numbers are accurate and
> representative of the action, friction does not appear to be a problem.
> Those two numbers give a balance weight of 38 grams, not out of the
> workable range.
>
> How many leads are there in the bass keys? Seems as though you may have an
> inertia problem (too much mass in system). How did you measure action
> ratio?
>
> I find these action problems always fun and challenging - as I learn a
> great deal each time I work through one of these. Please keep us informed
> of your evaluation.
>
> Terry Farrell
>   ----- Original Message -----
>
>   I am now looking after a 12 year old Petrof concert grand which has been
> aquired by a church for recital use etc.  It is a super piano tonally
> and in great condition, but it looks as though I will have to attend to
> the touch in the near future.  I have played it extensively myself and
> had a top rate professional pianist try it out and the basic problem
> appears to be that it becomes tiring to play because the touch 'appears'
> heavy.  On measuring the touch weight weight however, it comes out at an
> average of 48g (easy) downwight and 28g up. Present regulation is very
> good.  It is Renner action with smallish Renner hammers which I am sure
> are original. The action ratio is in the 5.5 range.  It has to be said
> that I intend  taking the action apart and check out all the centering
> and any key friction, and I expect this to make the touch more even.
> That said,  I still appear to have a fundamental problem which I will
> need to be addressed, and I am asking for comments and ideas on how to
> approach this.
>   Don't hold back!
>
>   ric