I have noticed this problem too, and find that [it occurs] when the
cardboard core of a music roll is too wide, (wider than the paper).
When rewinding, the paper has room to wander back and forth, and if
not tapped down on the slotted flange every time it is rewound, the
roll will not track well the next time the roll is played.  (That is
on *my* player; your player may be different.)

If the paper is allowed to stay in this "wandering" position, eventu-
ally it forms a memory in the paper and it will always wander from
side to side, getting worse as time goes on.

I think the real problem is: different players rewind differently, and
if they are out of alignment in the slightest, they can be rough on the
edges of new rolls.  If there is a space to allow the roll to wander,
on rewind,  it can save the edge, especially if it is tapped down
*every* time the roll is played and rewound.

On my model A Ampico, this extra space makes tracking worse!  The rolls
have to be tapped pretty hard to get the paper back in line with the
slotted flange, and I have even broken some flanges trying to get the
paper back in line.

Therefore, I have trimmed each core slightly shorter than the width of
the paper and the rolls wind up, and do not wander in the slightest
bit.  They play and track perfectly.  However I would like to add that
the removable flange should be slightly loose to allow for slight
expansion and contraction of the paper during variances of moisture
content in the paper.

The same roll on a model B Ampico might benefit from this extra space,
as the model B is notorious for being rather rough on the edges of
rolls.  So notorious was this fact, that men from the Ampico factory
would take cardboard roll cores and put them on a lathe, and cut thin
cardboard rings to place on the removable flange end of rolls, to make
rewinding a bit easier on rolls.

The problem has been around a long time, but it all boils down to the
particular piano -- the alignment of the spool in relationship to the
roll chucks; the alignment of the tracker bar; and how it handles rolls
during rewind, and playing.

When your player is rewinding, watch the edge of the paper closely.
Experiment with a shorter core, and a wider core, and use the one that
works best for you.

Bruce Clark