It was mentioned, associated with the thread on large rolls stalling with
wind motor driven rolls, that the Ampico B used a powerful electric motor
for roll drive, which they did.

The Ampico B has another device that was considered necessary to handle
the jumbo rolls, and that was variable braking on the roll tensioning
device, to try to maintain the same tension on the paper regardless of
how drastically the diameter of the roll changed from beginning to end.

The roll brake is pneumatic adjusted by a lever that rides on the roll as
it accumulates on the take up spool.  The lever pulls a needle valve out
of its opening thus lessening the vacuum, hence the braking force, in the
bleed fed pneumatic applying the roll brake as the roll plays out.

On the subject of roll damage during reroll: The Ampico B's tracking
system design incorporates a very positive roll centering action for
reroll.  This position is independently adjustable, and I find that
taking time to get this exactly right definitely helps in reducing
reroll damage.

Sincerely,
Dick Merchant
Carlsbad, New Mexico

 [ Long ago player tech Iver Becklund showed me how to restore and
 [ adjust the Ampico B tracker so that the valve-faces in the system
 [ oscillated at high speed (the valve, not the pneumatic!).  This
 [ improved the system from a "bang-bang" control into a completely
 [ linear chopper-amplifier servo.  I had to add an extra supply hose
 [ to the drawer to handle the air-demand, however.  -- Robbie