Paper Transport System41Paper Transport SystemFigure 13. Paper Transport SystemA two-phase DC stepper motor, directed by the EC on the controller board,drives two tractor sprockets by means of a toothed belt and splined shaftpulley arrangement. The stepper motor permits extremely accurateincremental vertical paper movement. This drive configuration is designed forcontinuous, fan-folded paper three to 17 inches wide and one to six sheetsthick. For reverse paper feeding, the platen open motor opens and closes theplaten via a toothed belt. Opening the platen prevents paper jams when paperdirection is reversed—that is, paper is moved downwards—in order to viewthe print area, set top of form, or allow applications to overprint forms.Paper is positioned horizontally using the tractors and the horizontaladjustment knob. Each tractor engages paper perforations with six sprocketpins and locks in place with a friction lock. The horizontal adjustment knoballows vernier positioning of the left print margin.Paper can be positioned vertically by hand with the vertical adjustment knob.Paper SupportsShuttle CoverAssemblyTractorSupport ShaftHorizontalAdjustmentKnobTractorsPaper PathSplinedShaftVerticalAdjustmentKnob andSplined ShaftPulleyPaper Feed TimingBelt (under the cover)
