[ Ref. 081017 MMDigest, Player Piano Actions With Die-cast Valves ]

Bob Conant wrote to the MMD:

> Just an old memory of mine.  Has anyone else run across these
> Wurlitzer die-cast valve housings?

My Caliola player stack came with the four-in-one die-cast units.
Also from the same collection was a number of extra die-cast assemblies
and some attempts at replicating this style valve with aluminum sand
casting.

Bill Black advised me how to work on these valves.  Since then he has
posted a detailed description of the process to the Caliola article at
his web site:

  http://www.carousels.com/caliola/ten.php  and
  http://www.carousels.com/caliola/eleven.php 

I have learned that the center cores are adjustable.  The two sides
of the spool are actually held by a drop of shellac (probably burnt
shellac).  Soaking the wooden cores in alcohol causes the two halves
to separate.  In cases where hot glue was used these can also be
taken apart by steaming the unit.

I built a simple jig so when I re-leathered all the valves in my
Caliola I could set the depth without adding more packing material.
I used thick orange shellac for re-setting the valve seats.

Some years ago I looked into machining the aluminum castings.  This
proved to be too much work as the walls of the casting are quite thin.
Russ Doering was assisting me with this.  Since Russ had a plastic
injection molding machine I did some serious work making detailed CAD
drawings for tooling a mold.

The valves are actually made of three parts, not counting the leather
and wooden core units.  In my case I have from a Wurlitzer-R player
a large number of the manifold cover plates.  The center part is what
I need for another project.  The bed plate is stamped aluminum.  For
my next project I have half the number of center cores as needed.

After more discussion with Russ earlier this year we decided that,
rather than to make an injection mold, it would be better to make
a silicone rubber mold and use a casting resin instead of machining
a metal mold.  Another advantage of using a silicone rubber mold is
that it can also be used for casting low temperature metal alloys.
I got as far as purchasing the silicone an resin for some tests.  This
is a project I expect to continue as soon as I get my workshop ready
for winter.

I expect the use of new materials will create some controversy.  The
goal here is to produce a working instrument.  It is also known that
the old pot metal has a limited life expectancy.  The casting resin is
a modern form similar to Bakelite.  Examining the samples in the store
(some of which I know to be a decade old or more and subject to a lot
of handling) I would expect the casting resin to last at least as long
as the pot metal.

I like working with this valve design.  There are some advantages over
making and adjusting the wooden unit valves.

Julie Porter