[ Ref. Early Duo-Art Roll Tracking Problem

The recent discussions on piano roll tracking all seem to have omitted
one important aspect which should be obvious, but can bear calling out:
centering of the take-up spool.  This should be the final step in any
comprehensive tracking alignment.

Once all of the other components have been adjusted to the center of
their excursions, take care to see that the take-up spool is likewise
centered so that there is equal distance on each side between the
inside of its flanges and the edges of the paper.  A misalignment here
will typically reveal itself within the first minute of playing and can
lead to severe paper damage if not corrected promptly.

The adjustment mechanism varies among manufacturers but in the case of
the Duo-Art typically takes the form of a small hex fitting outside the
left-hand side of the spool box which is turned clockwise to push the
spool to the right and counter-clockwise to allow it to move to the
left under spring pressure from the right-hand carrier.

This fitting is hollow and communicates with the hole in the take-up
spool which senses the presence or absence of paper to trigger the
repeat pneumatic or the motor cut-off switch pneumatic, depending on
the setting of the repeat switch.

John Grant