Just a week ago the Holtzer-Cabot motor of my Chickering Ampico A
failed.  Upon disassembly I noticed that all three carbon (graphite?)
linkages between the springs and their pivoting contact arms were
broken.

The material of the three pivoting contacts that disconnect by
centrifugal force after initial power application seems to me to be
cast bronze.  I need to find some replacements for the three carbon
pieces to which the springs connect.

I don't understand the necessity of them being made of carbon rather
than bronze, copper or any other conducting material.  I could make
those little buggers from scratch from any other material except
carbon.

Meanwhile, I have installed a 'pancake' motor, made by Westinghouse
for the American Piano Co., as it states on the nameplate.  The speed
is listed as 1140 RPM versus 1150 RPM on the Holtzer-Cabot motor, and
2.8 Amperes is listed for the H-C motor versus 1.9 Amperes for the
Westinghouse motor.  That's quite a difference.  In spite of this it
seems to perform well (so far), does not overheat and runs quietly.

By the way, I am almost done with installing the Gerety-Chase e-valve
system.  I had completed its initial trial runs when the Holtzer-Cabot
motor gave up the ghost.

So, my questions are:

1. Does somebody make replacement for those three carbon linkages?

2. Why is carbon used instead of any other conducting material?

3. Does anyone have a complete switching mechanism available that he
or she is willing to part with?

Please contact me by e-mail if so preferred.

Albert de Boer