I was wondering what response the span question would garner.  On
some pianos that are usually early models there is no stop rail for
the whippen or the pneumatics so the opening of the pneumatic is
critical.  On some later players there is either a stop rail for the
pneumatics or the whippen.  These later ones give some room for an
opening span greater than actually needed.

Standard Pneumatic Player Co. actions come to mind as one example
with the stop rail.  One model player action that I have seen has
four rows of pneumatics and is known as a four-tier stack.  These are
almost square and somewhat wide.  There was no stop rail of any kind
in this player so I measured the amount of travel the whippen needed
to play the piano and added the thickness of the felt punching inside
the side the pneumatic to figure the inside span of the pneumatic.

A pneumatic fully open has more power than one that is half closed.
Several makes of coin pianos had no stop rail so it is best to measure
everything before you start restoring one.

If I am are doing a wind motor that someone may have done before,
then I turn the motor by hand to see how much travel the pneumatic
needs and add 1/4-inch.  This pneumatic must have some fold to work
when fully open.  Pumps are the same situation in that there has to
be a fold to the cloth so the bellows close with the cloth going in
and not blowing outward.

Another thought off the subject concerning the glue that may have
been previously used.  If you cannot remove the glue successfully then
make new boards from poplar or maple and then shellac the inside and
outside, avoiding the part where the hinge is glued.

Don Teach - Shreveport Music Co.
Shreveport, Louisiana