Many of our subscribers will be interested to know about another use of
Delrin.  It's not in a solenoid piano, however.

In the mid 1970's, Werner Eisen, an industrialist from the Black Forest
town of Trossingen, Germany, and his designer, Hans Messner, were
called on by a company called Studio Oyen, headquartered in Wermels-
kirchen in the Rhine country near Cologne, to manufacture a run of
replicas of a 'Symphonion' disc musical box.  It turned out to actually
be a replica of a Kalliope Model 50G with a single comb and six bells.
One of these replicas is in the Wineburgh's collection.

Several manufacturing hurdles needed to be overcome in order to make
the musical boxes as they were totally new to the field.  Particular
to the subject here was the use of Delrin for dampers!

For our friends on MMD not familiar with musical box dampers:  They are
small 'appendages' to the comb teeth, either integral to the tooth on a
cylinder musical box or on a rail in a disc musical box so that each
damper stands in close proximity to its assigned tooth.

As the cylinder (or disc) revolves, the action of the pin on the cylin-
der (or the star wheel activated by a projection on a disc) forces the
damper upon the tuned tooth.  The tooth is thus forced to stop vibrat-
ing immediately before being plucked by the pin (or the star wheel).

The choice for dampers in the 1970's version of the Kalliope was
Delrin!  The wear and fatigue resistance coupled with the elasticity
of the product made it a clear choice over other candidates.  It might
also be noted that Eisen's factory was set up for injection molding
Delrin!  The stress testing included putting the Delrin-equipped star
wheels through a punishing one million cycles (eight million rotations
of a star wheel containing eight Delrin dampers) and showed no
noticeable wear or changes to their properties.

The design they used was quite interesting.  Eisen and Messner replaced
the old dampers-on-a rail system with dampers incorporated into the
star wheels.  Each star wheel (there is one star wheel for each comb
tooth) has eight projections around the star wheel circumference.
Each projection has an associated 'tongue' of Delrin molded into
cutouts in the brass body of the wheel immediately ahead of the
projection.

Thus, as a star wheel turns to strike a tooth on the comb, the Delrin
damper precedes it to stop the tooth from vibrating before the star
wheel projection plucks the tooth.  Oh, and the Delrin used was white
(not black) in color.

By the way, there are several applications of Delrin in the music
field.  M. Hohner, Inc. (coincidentally also headquartered in Trot-
tingen, Germany) used Delrin in the slide and resonating chambers of
their Model 2016 CBH, called "The Professional".

An even earlier musical use of Delrin (before commercialization of
the product) was as a replacement for crow quills in the plectra of
harpsichords!

Information for this article was obtained from the March-April 1977
issue of DuPont Magazine, the makers of Delrin.

There is a very thorough article about the manufacturing of the
Kalliope replicas by Arthur Ord-Hume in "The Music Box", the excellent
publication of the Musical Box Society of Great Britain, Volume 6,
No.  7 (1974) on pages 440-443 and 469.

Musically yours,

Bill Wineburgh
WWineburgh@aol.com
http://members.aol.com/WWineburgh/musicbox.html