Re vector problem

[Kenneth Sloane]

                      Subject:                              Time:  1:51 PM
  OFFICE MEMO         Re vector problem                     Date:  5/2/95

              --------ORIGINAL POST------

> Date:          Tue, 02 May 1995 06:42:38 -0600 (MDT)
> From:          Serge Harel <harel@LLC.org>
> Subject:       Vector problem

> My question
>
>     One of my costumer has a Kawai piano ten years old
> and she tell me that is action is to heavy. After a standard
> regulation of the action the feeling is still on the heavy side.
> l' found that the captans was under the magic line
> for 1/8 of a inch.
>
> What do you do  to corect that?

-----------MY REPLY-------------

The theoretical, straight line relationship between the wip flange center,
capstan/wip cushion bearing, and key bearing should exist to prevent skating
between the capstan and wip cushion bearing. If there is no skating here,
friction is essentially eliminated at this point. Make a visual check to see
if skating occurs. Also, you can take two pieces of abrasive paper (I suggest
120 grit) a little larger than the size of a capstan top and glue the non
abrasive sides together. Measure downweight on a key and then insert this
piece of "two-sided" abrasive paper between the capstan and the wip cushion
bearing. Measure downweight on the key again. If there is no change  in the
downweight (don't sweat a gram), there is, practically speaking, no skating
between the capstan and the wip cushion bearing and the "straight line
relationship" I described a few sentences ago is close enough. Be careful not
to mar the capstan top. You can buff it up just to be sure after you are done
your measurements.

Ken Sloane,  Oberlin Conservatory