teflon

[Don Mannino]

      Vince Mrykalo wrote:

>I thought to have a certain amount of friction is of great importance
>to the tone of the instrument (i.e. Rick Baldassin's and Chris
>Robinson's class on friction).

This is a common misconception, because it is true with cloth bushings. What is
needed for good tone is solid control of the hammer shank / hammer assembly, so
that there is no wobbling of the parts to rob (or mis-direct) energy away from
the strings.  With cloth bushings, a certain amount of friction is required to
insure the firm fit of the parts. If you can achieve the same tight fit with low
friction and without loss of control (as with teflon bushings), you will still
have good tone.  Teflon is so doggone hard, it insures excellent power transfer
when properly fit. It also can lead to a noisy action, even aside from the
clicking syndrome.

If the friction is very low in the hammer center, you might have trouble
regulating your repetition springs and drop settings to prevent bobbling hammers
during soft play. A little added friction at the balancier center can compensate
without adding significantly to the touchweight of the action.

The action does need to have friction for other reasons, too. An action with too
little friction will usually feel out of control to the pianist, unless the the
parts are so low in mass that they don't require much damping.

Don Mannino RPT
74473.624@compuserve.com