Damper TouchWeight

[Delwin D Fandrich]

----- Original Message -----
From: "Tom Driscoll" <tomtuner@mediaone.net>
To: <pianotech@ptg.org>
Sent: August 08, 2001 9:00 AM
Subject: Re: Damper TouchWeight


>
> From: Delwin D Fandrich <pianobuilders@olynet.com>
> Subject: Re: Damper TouchWeight
>
>
> Del ,
>            Would the weights be placed on the damper heads?  How heavy
and
> how installed?
> Thanks, Tom Driscoll
> ------------------------------------------------------

Placing them on the damper head would be ideal but I don't know how you
would do it and keep them from interfering with things and/or coming loose.
With our upright we solved the problem by switching from wood damper barrels
to brass barrels (both from Renner). Obviously this would be overkill in
most simple damper ringing cases.

Much more practical is locating them on the damper wire. Exactly how this is
done depends on the types of fishing that go on in your area and the types
of leads available. The best I've seen so far is a relatively long
football-shaped lead with a slit through to a longitudinal hole running
through the middle. They come in several different sizes. As I recall from
the last time this came up, the store I visited carried three sizes that
were physically practical. I would carry a couple of each of these for trial
use.

How heavy? That depends on the piano and the extent of the damping problem.
Make sure the dampers are mechanically working the way they should be
working--that is, spoons smooth and shiny, spoons properly adjusted, action
centers free, damper felts in reasonable condition, etc. Then back off on
the damper springs until they exert only a reasonable amount of force
against the string--no, I don't have a measurement for this, I go by feel.
One day I'll measure it. Or I'll ask Roger. But you shouldn't really feel
the damper kick in under anything above pianissimo.

Now listen to the piano. Find a couple of real ringers--the kind you would
normally really stiffen the spring on--and clip on the lightest of your
leads. Now listen again. If that didn't quite do it, go up a size and listen
again. Remember that there is a certain amount of interactivity here. In
general, use the larger weights toward the lower bass and the smaller
weights toward the upper bass. Don't forget the hacked-up mini-dampers just
above the bass/tenor crossover.

Once you've selected the appropriate leads, put a couple of drops of PVC-E
or white glue in the hole, slip it over the wire just above the wood lever
and lightly crimp it in place. Don't use CA glue. It won't stand up to this
kind of load. The glue is really only there to keep the lead from rattling
and/or buzzing.

Once the damper leavers are properly mass-loaded, you'll find that much less
damper spring pressure is needed for good damping.

There is more on this issue in the PT Journal. See
The Designer's Notebook
 Dampers—Why Are They So Darn Much Trouble?
December, 1995
in which I discuss the need for such mass-loading but not much on how to do
it.

Del