25070

Check current drift value: Navigate to NCK Diagnostics > Service Displays > Axis Monitoring, select affected axis and observe actual drift compensation value.

Verify MD36710 DRIFT_LIMIT setting for the affected axis. Typical value is 200-500 encoder increments. Check if value is appropriately set for your drive resolution.

Mechanically inspect axis for worn ball screws, loose couplings, bearing play, brake drag, or guideway contamination that would cause position drift.

Do not increase MD36710 without addressing mechanical root cause - this masks safety-critical wear issues

Reset drift compensation: Execute synchronization action or power cycle NCK after mechanical repairs. Monitor drift accumulation rate over several operating cycles.

Check drive amplifier temperatures via NCK > Commissioning > Drive > Drive Monitoring. Compare to rated operating temperature range.

Inspect analog interface connections between NCK and drive: check X411/X421 analog output signals and feedback connections for noise, ground loops, or deteriorated shielding.

Perform analog drive offset calibration: Access NCK > Commissioning > Axis > Analog Interface, execute automatic offset compensation routine with axis mechanically locked.

Ensure axis is mechanically secured before offset calibration

If drift persists, measure analog command voltage at drive input terminals during standstill. Should be <50mV offset. Replace drive amplifier if electronics are faulty.

Check encoder signal quality: NCK > Diagnostics > Drive > Encoder Signals. Verify amplitude levels are within specification (typically 1Vpp for analog encoders, proper TTL levels for digital).

Inspect encoder for contamination, moisture ingress, cable damage, or connector corrosion. Clean encoder scale and read head per manufacturer specifications.

Verify encoder reference mark is detected consistently: Execute reference point approach multiple times and check NCK display for consistent encoder offset values.

Check MD31020 ENCODER_TYPE and MD31050 ENC_IS_DIRECT for correct encoder configuration. Mismatched settings cause position calculation errors appearing as drift.

Review servo optimization: NCK > Commissioning > Axis > Controller. Check MD32200 POSCTRL_GAIN (Kv factor) and MD32910 DYN_POSCTRL_GAIN for appropriate values (typical 1-10).

Verify MD32800 EQUIV_SPEEDCTRL_TIME is correctly set for drive inertia matching. Incorrect value causes position lag appearing as drift.

Check MD36300 AX_MOTION_DIR and MD31020 ENCODER_TYPE match actual mechanical/electrical configuration. Inverted direction causes continuous following error compensation.

Execute servo optimization routine: NCK > Commissioning > Axis > Optimization > Automatic Servo Tuning. This recalculates optimal controller parameters and resets drift compensation.

Ensure machine is unloaded and axis moves freely before automatic optimization

On vertical axes, verify counterbalance system pressure (pneumatic/hydraulic). Check MD37100 BRAKE_MODE_MASK is correctly configured for axis orientation.

Check motor holding brake: Execute brake test via NCK > Diagnostics > Drive > Brake Test. Verify brake releases completely and does not drag during motion.

Secure axis against falling before brake testing vertical axes

Measure standstill current demand: NCK > Diagnostics > Axis Monitoring > Actual Torque. Excessive holding current (>15% rated) indicates external force or brake drag.

Review MD36710 DRIFT_LIMIT value relative to application. For vertical axes with expected load variation, value may need adjustment after addressing mechanical issues.