Hello MMD'ers!  I have a question regarding primary valves, and their
location relative to their respective secondary valves.  I have a
"home-brew-build-up" 'O' roll orchestrion that I've been working on
for 21 (yes, 21!) years.

I now have all of the solo instruments in it, meaning a re-iterating
xylophone, single-stroke orchestra bells, and a small electronic organ
(for the pipes).  The solo instruments are contained in a side chest
attached to the right side of the piano.  All of the percussion
instruments are contained in the top of the piano by way of a cabinet
extension.  (This machine is affectionately known as "The Beast".)

The xylophone uses a small outboard valve chest to apply vacuum to each
note, which operates the valve _in_ the xylophone valve chest.  The
pneumatic has a pallet valve on the chest directly behind it, which is
opened by a small wire being pushed by the beater rod.  This in turn
spills atmosphere into the valve, which turns the note off.  The
pneumatic opens, and the process starts over again.

I'm explaining all of this for a reason -- I'm about ready to tie in
the valve chest for the bells, and now I have a question.  (I hope you
are still with me!)

The small valve chest that operates the xylophone is teed into the
piano pneumatic stack.  Both the small valve chest and stack valves are
inside types.  (I do have a small amount of sluggishness with those 24
notes, but it is not a problem.)

What I _was_ planning on doing was using a 24-note primary valve chest
to provide the atmosphere signal.  The primary chest would then be the
signal source to run the xylophone small valve chest (which then
supplies vacuum to the xylophone valves) _as well as_ the valves to
drive the orchestra bells (which are also inside valves):

TRACKER BAR <---------T------------------PRIMARY VALVES
                      |            ^           |
                      |            |           | <- [atmosphere signal]
                      |            |           |
                 PIANO STACK       |
T------------ORCHESTRA BELLS
                                   |           |
VALVES
           this run will be--------|           |                      |
                3~4 feet                       |                      |
                                    XYLOPHONE DRIVE VALVE CHEST       |
                                               |                      |
                                               |                BELL
PNEUMATIC
                                      XYLOPHONE VALVE CHEST
                                               |
                                               |
                                      XYLOPHONE PNEUMATIC

I realize that I might be "over-doing" it, but the xylophone's chest
valves induce a _lot_ of vacuum level bouncing when a note is playing.
I _have to_ use the small inside valve chest to drive the valves in the
xylophone.

I know that one way would be to use the primary valve chest to drive
all three valves (piano, xylophone drive, bells) but that is not
possible, due to space restrictions in the top of the piano.  The right
side of the top of the piano stack is cluttered with the roll drive
motor and the rewind pneumatic with its' valves, so I can't mount the
primary chest there.

I plan to mount the primary valve chest, the xylophone drive valve
chest, and the orchestra valve chest (which connects with ~3/8" tubing
to the individual bell pneumatics) in the bottom of the side chest.
This will enable me to have all of the valves in one place, and
connected.

Now the question:  Is the primary valve chest supposed to near the
tracker bar, or it is supposed to be near the valves it is operating?

I thought the primary should be close to the secondary it is feeding.
Someone told me that the primary valve should be right at the tracker
bar.

All connections from the tracker bar to the valve chests and stack are
all 5/32" tracker bar sized tubing.  Drilling into the stack to tap the
vacuum signal going to the stack pneumatics would help, but that is not
possible.

Any ideas?

Mike Carey