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Check Axis Movement

Put machine in HANDLE JOG mode and manually move the affected axis at slow speeds to feel for binding or rough spots.

Ensure all safety interlocks are active before manual movement

Inspect Way Covers and Bellows

Remove way covers and inspect for chip buildup, coolant residue, or damaged bellows that may be interfering with axis travel.

Look for shiny wear marks on ways that indicate contact points

Check Ball Screw and Nut

Inspect ball screw for damage, contamination, or loss of lubrication. Listen for unusual noise during slow jogging movements.

A dry ball screw will often make a squeaking or grinding sound

Verify Gibs and Preload

Check gib adjustments for proper preload - too tight causes binding, too loose causes chatter and following errors during direction changes.

Check Drive Status LEDs

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

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

Monitor Servo Load Display

Access CURRENT COMMANDS > POSITION and observe the servo load percentage during jogging. Excessive load (>80%) indicates drive or motor issues.

Compare load values between axes - significant differences indicate problems

Check Motor Connections

Inspect motor power and encoder cable connections for corrosion, looseness, or damage. Verify proper seating of all connectors.

Encoder cables are sensitive to EMI - ensure proper routing away from power cables

Verify Drive Parameters

Access SETTING > PARAMETERS and verify servo-related parameters (28-35) match machine specifications. Document any changes made.

Check Encoder Cable Integrity

Inspect encoder cables for cuts, pinch points, or excessive bending. Pay attention to cable tracks and areas where cables flex during axis movement.

Encoder problems often show up as intermittent alarms during rapid movements

Monitor Position Display

Access CURRENT COMMANDS > POSITION and watch for erratic position readings or sudden jumps in displayed position values during slow jogging.

Sudden position jumps can cause unexpected machine movement

Verify Encoder Mounting

Check encoder mounting hardware for looseness or damage. Ensure proper coupling between encoder and ball screw or motor shaft.

A loose encoder coupling will show up as following errors during acceleration and deceleration

Test Encoder Signal Quality

Use oscilloscope to verify clean encoder signals if available, or swap encoder cables between axes to isolate cable vs. encoder issues.

Review Parameter 29 Setting

Access SETTING > PARAMETERS and check Parameter 29 value. Compare against Haas factory specifications for your machine model.

Typical values range from 0.005" to 0.020" depending on machine size and application

Monitor Following Error

Use CURRENT COMMANDS > POSITION to observe actual following error values during normal operation before alarm occurs.

Do not increase Parameter 29 beyond factory specifications without understanding accuracy implications

Test with Temporary Adjustment

If following error approaches but doesn't exceed normal limits, temporarily increase Parameter 29 by 25% to test if alarm clears during normal operation.

Document original parameter values before making any changes

Verify Machine Specifications

Consult machine manual or contact Haas to confirm proper Parameter 29 setting for your specific machine model and serial number.