In MMD 06.09.06 , Niels Berkers is having problems with his
late Aeolian player piano:

> ...  a few notes will only sound when pedaling very hard.
> The others all work fine.

I hope we are talking about the same player.  The later Aeolian is the
one with the plastic valves and the stack under the keybed.  It also
has the tempo regulator on the left of the spool box with the air motor
just above it.

I don't think your problem is with the bleeds.  On the plastic valves
they just drilled hole in part of the plastic shell for the bleed and
it won't pop out.  Your problem is probably due to old, hard pneumatic
cloth.  Old cloth gets hard and the rubber flakes off and starts
leaking a bit.  This allows the cloth to flex at the creases, even
through the cloth is hard, but takes more vacuum to get it to operate.
With most of the pneumatics in this leaking state, the playing volume
will reduce all of a sudden when playing a large number of notes at
the same time.  I know you didn't talk about this, but read on.

The other problem with the hard cloth is that the hinge is made from
the same material.  With hard cloth at the hinge and if excess glue
was used in the gluing, it won't want to close, which might explain why
some of the keys only play when pumping hard.

Mark the keys that are not playing and locate the pneumatics that are
associated with the bad keys.  Manually operate the pneumatic with your
finger and see how much force it takes to close the pneumatic and still
get the note to play.  If they are considerably harder to move than the
good keys, you found the problem.  You could just replace the few that
are bad but the real fix is to replace all of the pneumatic cloth on
the stack.  You will be surprised at how much better the player will
play with all new cloth.

Another problem that could cause the same problem is a leaky valve.
Dirt can get into the valves and cause them to leak when played.
If you hear a continuous hiss in the valve area when the bad note is
played, then remove the hose on the valve and operate it by covering
the nipple with your finger.  If it still sounds like it is leaking,
attach a hose to the nipple and use your mouth to force the valve open
and closed with a sucking and blowing action.  This sometimes clears
the problem.  If not, then the valve needs fixing.

Another problem might be a clogged or kinked hose between the tracker
bar and the stack.  There are a lot of hoses going through a small
opening at the ends of the piano.  The hose that is closest to the
outside sometimes gets crushed when it contacts the edge of the wood.


> Also, the larger music rolls will barely play when I'm near the end
> of the roll, as if there's too much drag, but the brakes are all off.

As far as the braking problem, check the tension of the paper above
the tracker bar while the roll is playing.  You indicated that all of
the brakes are OFF so this means that there shouldn't be any tension on
the paper as it comes off of the top roll, which could be your problem
too.  If it is tight, then the problem might be that the transmission
needs lubricating.

If you find that the problem is in the top brake, I would clean off all
oil on the brake drum and replace the felt on the brake shoe.  I know
that some people on the list have indicated to use a drop of oil on the
brakes but don't use any oil on either surface.  If it is clean, it
will remain clean and keep the same tension on the paper for years.
Once you put oil on it, it starts collecting dirt and will gum up due
to temperature changes and need more attention later.

If there are already signs of oil or a greasy substance on the brake
drum, go ahead and use a drop of oil on it and try to remove as much
of the grease from the shoe and drum using a paper towel or rag.  Doing
this on an already oiled brake won't hurt it any more than it already
is.

You didn't explain what really happens to the roll when it gets to the
end of the long roll.  Does the paper stop over the tracker bar while
the bottom take up spool is still turning?

If this is the case, then you have the top tension on the roll too
loose.  There has to be tension on the top roll.  If it is too loose,
then the paper slips across itself on the take up spool, causing the
diameter of the paper on the take up spool to get smaller and the paper
slips even more.

As paper is removed from the top feed roll, the diameter gets smaller.
This causes the tension of the paper at the end of the roll to be
greater than at the start.  Experiment with different tensions so at
the end of the song you don't put too much drag on the motor and slow
down the music and it doesn't slip either.

This tension also helps the tracking system of the player when it is
playing the roll.  I would suggest disabling the bottom brake when the
roll is rewinding.  The extra tension seems to cause the paper to tear
when you get a roll that starts snaking left and right while rewinding.

Hope this helps.
Pete Knobloch
Tempe, Arizona