Slick Key Bushings.

[Tom Servinsky]

Issac wrote:
> When the pianist play, we may not suppose that he always move his fingers
> vertically, often the side of the bushing is dragging on the pin.
>
Which is why many techs often mis-read friction problems vs legitimate
downweight problems. THANK YOU DAVID STANDWOOD!!!!!!
The general nature of our hand structure combined with what's being demanded
of the fingering constantly engages the sides of the bushing, pushing the
key to the extreme left or right position. Yet how many times has someone
complained about their heavy action and the good hearted tech begins to take
measurements.  Even though their trusty shiny brass gram weights show the
touch to be in the high 40 grms. dw with good appropriate upweight the
customer is still declaring there's a problem.
The difference is the tech is measuring the key with no stress on the
bushing vs the skilled pianist playing with stress on the bushing.
Lubricating the surface of the pin along with the bushing results in an
extraordinarily clean key movement.
Tom Servinsky,RPT