20

Check for physical obstructions

Manually jog each axis at slow feed rates using the JOG keys to feel for binding, rough spots, or mechanical resistance.

Ensure machine is in proper jog mode and use slow jog rates to avoid further damage

Inspect ways and ball screws

Look for crash damage, chips, or debris on linear ways and ball screw assemblies. Check way covers for proper alignment.

Use a flashlight to inspect under way covers - small chips can cause significant binding

Verify lubrication system

Check Parameter 310 (Lube Timer) and ensure way lubrication is functioning. Verify oil levels and pump operation through CURRENT COMMANDS > AUX FUNCTIONS.

Dry ways are a common cause of following errors after extended downtime

Test axis performance

Run a slow axis movement test and monitor following error in real-time through CURRENT COMMANDS > POSITION to identify which axis and location causes the fault.

Check servo drive status LEDs

Inspect the servo drive module LEDs in the electrical cabinet. Green indicates normal operation, red indicates drive fault.

Only qualified personnel should work inside electrical cabinet with proper lockout/tagout procedures

Verify motor cable connections

Check motor power and encoder cable connections at both motor and drive ends. Look for damaged, loose, or corroded connections.

Encoder cables are particularly sensitive to damage and can cause intermittent following errors

Monitor servo current draw

Use CURRENT COMMANDS > POSITION display to monitor axis load during movement. Excessive current draw indicates mechanical problems or motor issues.

Swap servo drives if possible

If multiple identical axes exist, swap servo drive modules to isolate whether the problem follows the drive or stays with the axis.

Power down machine and follow proper ESD procedures when handling drive modules

Check encoder cable integrity

Inspect encoder cables for damage, especially at cable track connections and motor junction boxes. Look for pinched, cut, or oil-contaminated cables.

Encoder cables should be routed separately from power cables to avoid electrical interference

Verify encoder coupling

Check encoder coupling at motor for looseness or damage. The encoder must be mechanically coupled to the motor shaft without slippage.

Test encoder signals

Use DIAGNOSTICS > ENCODER TEST to verify encoder counts are incrementing properly during manual axis movement.

Encoder counts should change smoothly and consistently - erratic counting indicates encoder problems

Check encoder power supply

Verify +5VDC encoder power supply voltage at the drive module and ensure clean power delivery to encoder circuits.

Review Parameter 17 settings

Check SETTING > PARAMETERS > Parameter 17 for each axis. Typical values are 0.005-0.020 inches depending on machine size and application.

Don't just increase Parameter 17 without finding root cause - this masks real problems

Check servo gain parameters

Review Parameters 70-79 (servo gains) and compare to factory defaults. Incorrect tuning can cause oscillation or poor following.

Only adjust servo parameters if you understand servo tuning - incorrect settings can cause instability

Monitor actual following error

Use CURRENT COMMANDS > POSITION to observe real-time following error during various feed rates and accelerations to determine if Parameter 17 is appropriate.

Reset to factory parameters

If parameters have been modified, consider restoring factory defaults through SETTING > PARAMETERS > RESTORE and retest.

Backup current parameters before restoring factory defaults

Check programmed feed rates

Review G-code for excessive F values that exceed machine capability. Compare to maximum feed rates in Parameter 8.

Following errors often occur during rapid positioning moves (G00) rather than feed moves (G01)

Verify acceleration parameters

Check Parameter 15 (Acceleration Time) and Parameter 16 (Deceleration Time) settings. Values too low cause excessive acceleration demands.

Increase acceleration time in small increments (0.1 second) to reduce servo demands

Test with reduced feed override

Run the same program with 25% feed override to determine if following error is feed rate dependent.

Monitor during different move types

Observe when following error occurs - during rapids, linear moves, or circular interpolation to identify specific motion causing the problem.