MPL-A420P-HJ22AA – X-axis motor assembly + Cone Drive AccuDrive gearbox

X-axis motor assembly – Allen-Bradley MPL-A420P-HJ22AA + Cone Drive AccuDrive gearbox

The X-axis motor assembly drives the print carriage. It comprises the Allen-Bradley servo motor and its right-angle gearbox, factory-fitted and aligned, and fits directly in place of the original assembly without the need for coupling adjustment.

The Allen-Bradley / Kinetix MPL-A420P-HJ22AA brushless AC servomotor (Rockwell P/N 7042-00-1202, Series A) is controlled in a closed-loop system by the Kinetix drive, with absolute encoder feedback. It is coupled to a Cone Drive AccuDrive right-angle gearbox, which adapts the torque and transmits the drive at a 90° angle to the carriage belt.

This drive train determines the consistency of the scanning speed across the entire print width, which is essential for the correct placement of ink droplets. If the gearbox exhibits play, noise or a sticking point, the entire assembly must be replaced: the motor alone is not sufficient.

Technical specifications

• Motor catalogue reference: MPL-A420P-HJ22AA
• Rockwell P/N: 7042-00-1202 – Series A
• Motor manufacturer: Allen-Bradley (Rockwell Automation) – Kinetix MP-Series range
• Gearbox manufacturer: Cone Drive Operations – AccuDrive, 90° right-angle gearbox
• Part type: fully assembled unit (Assy) – AC servomotor + gearbox
• Motor type: low-inertia brushless AC servo motor, integrated absolute encoder
• Axis concerned: X-axis – print carriage drive
• Power supply: 230 V RMS peak-to-peak, three-phase – frequency 0 to 333 Hz
• Power: 2.0 kW / 2.8 HP – continuous duty
• Maximum speed: 5,000 rpm
• Continuous holding torque: 4.74 Nm (42 lb.in)
• 0-peak continuous current: 12.7 A
• Voltage constant Ke: 53 V 0–peak between phases per 1,000 rpm
• Resistance between phases: 0.96 Ω at 25 °C
• Insulation class: 180 (H) – permissible ambient temperature 40 °C
• Protection rating: IP66 with shaft seal
• Control: Kinetix drive – voltage PWM control, absolute encoder feedback
• Delivery: complete, assembled unit, ready for installation

Identification prior to ordering

• It is the gearbox that determines the interchangeability of the unit, not the motor: note the model and reduction ratio shown on the Cone Drive AccuDrive nameplate
• Check the catalogue number of the existing motor: it must correspond to MPL-A420P-HJ22AA
• The MPL-A420P-HJ72AA and MPL-A420P-SJ72AA variants differ in terms of the encoder feedback, the shaft or the presence of a brake, and are not interchangeable without verification
• Check the output orientation of the right-angle gearbox and the centre-to-centre distance of the mounting holes on the frame
• Check the type of connectors and the length of the feedback and power cables
• If in doubt, please send us a photograph of both nameplates (motor and gearbox): we will confirm compatibility before dispatch

Function

• Drives the print carriage back and forth along the X-axis, above the table or the media
• Maintains a constant scanning speed across the entire print width, which is essential for correct droplet placement
• Ensures the carriage accelerates and decelerates at the end of its travel without losing position
• Transmits the drive at 90° via the AccuDrive gearbox to the carriage belt, adjusting torque and speed
• Feeds back the carriage’s actual position to the Kinetix drive via the integrated absolute encoder

Possible symptoms of wear

• X-axis fault or servo error on start-up; carriage fails to initialise
• Carriage jerks, moves in fits and starts or exhibits irregular speed during printing
• Vertical bands, registration misalignment between passes, double outlines
• Metallic noise, whistling or rumbling at the right-angle gearbox
• Perceptible mechanical play (backlash) in the carriage when the motor is stationary
• Abnormal motor overheating, thermal shutdown during continuous production
• Loss of position or encoder feedback error signalled by the drive

Replacing the X-axis motor assembly restores smooth carriage movement and eliminates print quality defects related to the kinematics. As the most common cause of failure on this axis is motor overheating, it is recommended that the ventilation and correct operation of the X-axis motor cooling kit be checked at the same time.

♻️ DG Spare Parts – European specialist in spare parts for large-format printers and plotters.