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MMD > Archives > September 2008 > 2008.09.16 > 10Prev  Next

Testing & Regulating Roll Reader Pouch Switches
By Mike Walter

I have an up-and-running Aeolian organ and an Estey console which
needs a lot of work.  Inasmuch as I have Estey music rolls I figured
that I would play them on the Aeolian console and manually set the
stops.  With a few minor modifications I was able to play the Estey
rolls.  Then I ran into an unexpected problem.

The first Estey roll I tried to play was #403, "The Snow is Dancing",
by Debussy.  This has a lot of arpeggios and they would not sound as
the roll was playing.  The roll speed specified was Tempo 60 and I had
to slow it down to Tempo 30 to get the notes with single hole punches
to sound.

I next played an Aeolian roll ("Toccata" from "Suite Gothique" by
Boëllmann,  #1217), which has sections where rapid single notes are
played.  The speed of this roll was Tempo 40 and the roll sounded all
of the notes.

I measured the punched hole sizes and found the Aeolian to be
approximately .044 inches diameter and the Estey rolls to be
approximately .040 inch diameter.  Further, I found that the Estey
notes which did not play were single holes, whereas the equivalent
note on the Aeolian roll was two overlapping holes, which I feel
is a significant difference.  I looked at several other Estey rolls
and did not find many more with single hole punches for single notes.

I have an Aeolian test roll which has single punched holes for the
notes, and when I played this roll many of the notes did not play
unless I slowed down the roll speed.  There was no roll speed specified
on this roll.

Does anyone have a recommended play speed for this Aeolian test roll or
know what repetition rate I should  expect?  The problem is associated
with the console and the roll playing portion of the organ since one
can play very fast notes manually.

Some questions I have are:

1. Is there a preferred procedure to adjust the two screws which
set the electrical contacts for each note on the console?  The proper
setting is needed to get a high repetition rate.

2. Is the Estey console more responsive and able to play a rapid note
formed by a single punched hole?

3. Is it possible that I need to rebuild the pneumatic section of my
Aeolian console to get a faster response?

4. Would it be effective to somewhat increase the pressure in the
pressurized roll box on the Aeolian?

5. Should a second punched overlapping hole be added on the Estey roll
notes which do not play with the single hole?

Mike Walter

 [ The pouches must be supple, stray leakage must be minimized and
 [ then equalized by bleed adjustment, and the spring force must be
 [ equalized before the contacts are adjusted.  See the technical
 [ article by Richard Vance, "Pneumatic Switch Assembly for Reading
 [ Music Rolls - A New Design to Make Contact Pouch Boards for
 [ Converting Player Roll Pneumatic Signals to Electrical Contact
 [ Closures", at 
 [ -- Robbie

(Message sent Tue 16 Sep 2008, 15:05:30 GMT, from time zone GMT-0700.)

Key Words in Subject:  Pouch, Reader, Regulating, Roll, Switches, Testing

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