HP 450c Service Manual - Page 184

Moving the Carriage CarriageĆDrive Mechanics Motor, Belt and Pulley D The carriage (YĆaxis) drive consists of a DC motor directly driving a single belt and the carriage. D The motor assembly itself provides the tension needed on the belt, eliminating the need for a separate pulley tensioner. D The belt clamps itself to the carriage; there are no separate belt clamps. D The interface between the motor shaft and belt is friction based. D You can remove the belt without having to remove the pulley on the left end of the belt. Carriage Guidance The carriage moves along on just one stainless steel slider rod. It is guided by two integrated bronze bushings, which are selfĆlubricating, and a back wheel. Positional Feedback An encoder strip provides feedback on the position of the carriage. The strip does not require adjustment. Carriage PCA The carriage PCA is based on that of the DesignJet 650C. It connects to the main PCA through a long 60Ćconductor (2x30) trailing cable. The carriage PCA contains: D Optical line sensor D Thermistor circuit D Linear encoder D Cartridge nozzle firing circuit Some electronic components on the DesignJet 450C and 450CA carriage PCA are not present on the DesignJet 430 carriage PCA. At powerĆon the Printer firmware identifies whether the carriage is for a color or a monochrome model, and behaves accordingly. 10-4 HP DesignJet 430, 450C and 455CA Printers Functional Overview