Portable printer with asymmetrically-damped media centering

An asymmetrically-damped media centering mechanism, comprising

• a first media support member moveable along a longitudinal axis thereof;
• a second media support member moveable along a longitudinal axis thereof;
• a reciprocal movement mechanism operably coupled to the first and second media support members, the reciprocal movement mechanism configured to translate a longitudinal movement of the first media support member into a corresponding opposite longitudinal movement of the second media support member;
• a pivoting arm coupled to the reciprocal movement mechanism and pivotable between at least a first and a second position, wherein the pivoting arm pivots to the first position when the first and second media support members are moved closer to each other, and the pivoting arm pivots to the second position when the first and second media support members are moved further apart from each other;
• and
• a damping gear configured to operably engage the reciprocal movement mechanism when the pivoting arm mechanism is in the first position and to disengage the reciprocal movement mechanism when the pivoting arm mechanism is in the second position.