Andy Ott has a Steinway Duo-Art that is tearing some of his older
rolls.  I have to assume that you have the tracker system that when
the piano is put into the re-roll position, both of the tracker ear
lines are closed off by a pouch cut-off valve.  Doing this should cause
the tracker pneumatics to move to the center.

The first thing that might change over time is a small leak in one of
the tracker pneumatics that would cause the pair to not center properly
during rewind.  This can also include a leak in one of the cut-out
valves due to dirt, a leather problem or even leaky pneumatic cloth.
If you do any adjustments with problems in the system, you will just be
compensating for the problem.

For the system to rewind well, the tracker must be adjusted properly
during play such that the paper on the bottom roll doesn't wander from
side to side.  The two tracker ears should be adjusted to where each
ear doesn't touch the paper except when it starts to move to either
side of the center line of the tracker bar.

I watch the expression holes on the left and right side of the tracker
bar holes and when they are covered by the same amount of paper then
I know that the paper is centered properly.  I usually find that having
a total gap of about twice the thickness of a playing card is about
right.

And don't adjust the fingers based on an extremely bad roll.  Play a
few rolls and make an assessment as to which roll is best.  While
playing the rolls, note how far off center the tracker pneumatics move.
They should be near centered most of the time and move slightly right
and left of center while playing a good roll.  If most of the good
rolls show that the tracker pneumatics is not centered most of the
time, then the rod linkage needs to be changed.

On the rod that links the tracker pneumatics to the roll shifting cam
are two nuts or even a turnbuckle that allows for adjusting the length
of the rod.  Loosen the nuts with a small open-end wrench so you can
make adjustments.  If the pneumatics is too far to the left, then you
have to effectively shorten the rod linkage.  If they are to the right,
lengthen the rod linkage.

As an example, if the tracker pneumatic is about 0.2 inches to the
right, you have to lengthen the rod by about 0.2 inches.  Now tighten
the nuts, start the player and see how close to center you have the
tracking pneumatics centered.  It might take a few tries to get it
right.

Now when you put the player into rewind, the tracker will center and
the upper roll should move to its optimal center position and align
with the paper on the bottom roll.  What you want is that when
rewinding, the roll doesn't rub excessively on the right or left side
of the top spool flanges.

I have a few older rolls that wander badly right and left during rewind
and I know it is only a matter of time before they destroy themselves.
To help solve this problem, I make sure that the left flange is opened
up a little and the roll paper is tapped to the right flange before
putting into the chucks.  I have also adjusted the tracking pneumatics
so that when the piano is put into rewind, the top roll moves ever so
slightly to the right so any wandering to the right won't tear the
right side of the older rolls.

Pete Knobloch