John Rutoskey was discussing PPCo. reroll pneumatic problems and it
got me to thinking about a constant bothersome detail on my Pratt-Read
player in a 1919 Fischer upright (burled walnut, non-electric, rebuilt
1997 by me).  It operates beautifully in all respects but one: the
damper pneumatic takes a finite time to close and open, delaying
slightly the lift and release of the dampers.

Most of the 88-note rolls that I pump through the machine seem to have
the damper holes aligned to the roll notes assuming a faster reaction
of the damper pneumatic.  This condition leads to the dampers coming
off the strings slightly late, which works out okay for most music.

But the dampers return to the strings a little late, which can lead to
notes ringing into the next chord/note sequence.  The pneumatic takes
about 1/4 to 1/3 second to open or close by my visual estimation,
whereas, the individual notes are being struck almost instantaneously
with the roll hole passing over the corresponding tracker bar hole.
This problem is more noticeable on some rolls than others.

There is at least 7-8 feet of tracker bar tubing and manual push button
tubing running to a switch on the spoolbox and a y-connector near the
pneumatic.  (This calculates out to about 2.6 cubic inches by volume).
I would guess that some delay is introduced by the volume of air that
must be moved to fill or evacuate those tubes on each cycle.  There is
a large supply tube running to the damper pneumatic, about 5/8" i.d.

I am wondering if I might benefit from an amplifier (adding a primary
valve unit) between the y-connector and the damper pneumatic.  I will
open up the pneumatic to see if things look hunky-dory (no blocked
bleeds, proper valve clearances, etc.).

Any comments would be appreciated.

Larry Toto

 [ The little book, Dictionary of Word Origins, by Jordan Almond,
 [ says that "hunky-dory" is from the Low Dutch and Danish word "honk",
 [ meaning safe.  The word was also used to mean a goal in a game,
 [ and so the man who scored or safely reached base in a game like
 [ baseball was said to "honk" or "be honkey".  "Dory" quite possibly
 [ comes from "all right."   -- Robbie