Key Ratio

[Richard Brekne]

Ok... but the same ratio is going to exist, as the balance pin hole (in this
case anyways) is perpendicular the top of the key. My thinking was more like
this. Stanwoods weight measuring method places the front of the key so its
resting on a spot just about 10 mm back from the key front. If this is where
one then also has to measure from (if you want to do it that way) then the two
results are pretty much the same.

The point is that the key ratio (as per standwood) is like really kinda high,
and is bound to cause problems in the way the action plays. And this puppy is
both heavy and clunky feeling. A ratio of 5.6 however doesnt seem to be so
unusual as far as I can tell. And thats what you come up with if you measure
as I first did, from the front of the key.

What I am wondering about is if this is a case of design failure or not. Could
the manufacturer have actually figured the key ratio by measuring from the
wrong spot ??.

For edification the action was produced by A.B. Lexow and has serial number
566522. The piano was made in 1913 I believe.

"David M. Porritt" wrote:

> Richard:
>
> Remember if you are measuring these lengths, the front is from the TOP of
> the key to the bottom of the key at the balance pin.  The back is measured
> from the bottom of the key at the balance pin to the top of the capstan.
> That is where the forces apply.
>
> dave
>
> *********** REPLY SEPARATOR  ***********
>
> On 10/3/00 at 10:22 PM Richard Brekne wrote:
>
> >In my continuing exploration of Stanwoods stuff I ran into an interesting
> >little dicrepency on my Duysen Grand action today. I have been scratching
> >my head a bit about the apparently high Key Ratio figure obtained by the
> >Standwood method. This hovered around .60 grams on all samples. Haveing
> >rechecked a few times without finding any other result I decided to
> measure
> >the distance between the center of the balance hole, and the capstan
> center
> >on the one end and the end of the key on the other end.
> >
> >To my suprise the measurements in lenghts resulted in a Key Ratio of 5.6.
> >Course I rechecked this several times to see if I could get the ratios to
> >coincide better but ended up with no real change.
> >
> >The distance from the center of the capstan to the center of the Balance
> >pin hole was 12.1  cm and the distance from the center of the Balance pin
> >hole to the key front was 21.5cm. The only thing I can think to explain
> >this is that Key ratio figured by lengths has to be taken from about 1 cm
> >back from the front of the key. Is this how its figured then ??
> >
> >--
> >Richard Brekne
> >RPT, N.P.T.F.
> >Bergen, Norway
>
> David M. Porritt
> dporritt@swbell.net
> Meadows School of the Arts
> Southern Methodist University
> Dallas, TX 75275

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway