The Carriage Axis Drive - ENCAD CADJET Service Manual

CadJet 3D Service Manual

The Carriage Axis Drive

The Carriage Axis Drive moves the printer's carriage assembly along
the length of the printer. The drive consists of a servo motor, linear
encoder strip, drive belt, and tensioning assembly. These items are
illustrated in Figure 2-3.
The servo motor, drive belt, and tensioning assembly are the compo-
nents that actually drive the carriage assembly. The servo motor drives
the belt back and forth allowing the attached carriage assembly to be
repositioned as required. The tensioning assembly is spring controlled
and allows the proper amount of tension on the belt.
The linear optical encoder strip is used to obtain the printers accuracy
along the axis of the printer. It is made with 150 parallel lines per inch
etched into it. By utilizing two optical encoder sensors that are slightly
off set from each other, and reading the leading and trailing edges of the
lines, a resolution of 600 dpi can be obtained.
The stepper and servo motors are controlled from the main printed
circuit board by the microprocessor.
2-4 Theory of Operation
Figure 2-3. Carriage Axis Drive.