A scoring bridge includes a plurality of moveable mounted carriages. The
carriages each have a rotor, and the bridge has a linear stator to move
the carriages. The position of a carriage designated as a reference
carriage is recorded as it moves past a motion detector. The position of
each remaining carriages is recorded as they individually move past the
detector. The difference between the position of a carriage and the
position of the reference carriage is an offset that is added to the
position reading of the carriage to accurately space the carriage form
the reference carriage. Each of the carriages can have a scoring assembly
that includes servomotor acting through a gear arrangement on a scoring
wheel. The servomotor applies a constant load to the scoring wheel and
adjusts the load for any positive or negative displacement of the scoring
wheel from a reference position.