Kodak NOVAJET 700 - Manual (Page 27)

Theory of Operation 2-3
NovaJet 500/630/700 Series Service Manual
THEORY OF OPERA
TION
Paper (Media) Axis Drive
LOWER ROLLER SHAFT ASSY
PINCH ROLLERS
STEPPER MOTOR
REDUCTION GEAR
Figure 2-2. Paper (Media) Axis Drive.
The Paper (Media) Axis Drive moves the plotting media in a direction
perpendicular to the length of the printer. This friction drive utilizes a
micro-step drive technology and consists of a stepper motor, reduction
gears, lower drive shaft assembly, and pinch rollers. This can be seen
in Figure 2-2.
The micro-step technology associated with the stepper motor gives the
capability of a resolution up to 9600 dpi.
The reduction gear meshes the stepper motor to the lower drive shaft
assembly which allows the media to advance or retract. The purpose of
the pinch rollers is to apply pressure to the media onto the drive shaft
assembly to reduce the chance of slipping.
Misaligned pinch wheels is a main cause of skewing of the media. For
that reason the NovaJet 500/630/700 Series was designed with self
aligning pinch rollers. As the media is fed forward, the rollers are
aligned correctly. However, these pinch rollers will not stay aligned
while the media is being fed backwards.