OT0501

Release Overtravel Condition

Hold the overtravel release button (if equipped) or follow machine-specific procedure to bypass the limit switch temporarily. Jog the axis in the positive direction until clear of the limit switch.

Move slowly to avoid sudden jerks that could damage components.

Ensure no personnel or tools are in the axis path during jogging.

Review Program Coordinates

Access the active program in the CNC control and check the coordinates for the affected axis. Look for negative values that exceed the machine's soft or hard limits.

Compare with the machine's documented travel limits in the manual.

Do not edit programs without proper authorization or backup.

Verify Work Offsets

Check the work offset values (e.g., G54-G59) for the affected axis. Correct any values that could push the axis beyond the negative limit.

Use a test run in dry mode to simulate the program after corrections.

Incorrect offsets can cause crashes; double-check all values.

Release Overtravel Condition

Hold the overtravel release button and jog the axis in the positive direction until the alarm clears and the axis is within safe limits.

Note the current position display to identify discrepancies.

Avoid rapid jogging to prevent mechanical stress.

Perform Machine Homing

Initiate the homing sequence for all axes as per the machine manual to reset the reference point. Ensure no obstructions are in the way during homing.

Watch for unusual sounds or jerky motion during homing, indicating potential issues.

Ensure the area is clear of personnel during homing.

Verify Origin Position

After homing, check the position display to confirm the axis origin matches the expected value. If incorrect, consult the machine manual for origin reset procedures.

Document the correct origin values for future reference.

Incorrect origin can lead to repeated alarms; escalate if unresolved.

Release Overtravel Condition

Hold the overtravel release button and carefully jog the axis in the positive direction to move away from the limit switch.

Mark the current position for reference during inspection.

Ensure power is off if accessing hardware near moving parts.

Inspect Limit Switch

Locate the negative limit switch for the affected axis. Visually check for damage, debris, or misalignment that could cause false triggering.

Clean the switch area with compressed air to remove dust or chips.

Do not adjust the switch position without proper tools or training.

Test Switch Operation

Use a multimeter to test the limit switch for continuity when activated and deactivated. Replace the switch if it fails the test.

Refer to the machine's electrical diagram for switch wiring details.

Disconnect power before testing to avoid electrical shock.

Release Overtravel Condition

Hold the overtravel release button and jog the axis in the positive direction to clear the alarm temporarily.

Record the position where the alarm triggered for comparison with soft limits.

Ensure no obstructions are in the axis path while jogging.

Access Soft Limit Parameters

Navigate to the parameter menu in the FANUC control (typically under maintenance mode) and locate the soft limit settings for the affected axis.

Backup current parameters before making changes.

Incorrect parameter changes can cause machine damage; proceed with caution.

Adjust Soft Limits

Compare the current soft limit values with the machine's physical limits. Adjust the negative soft limit if it is set too close to or beyond the hardware limit.

Set soft limits slightly inside hardware limits for added safety.

Test adjustments in a controlled environment before full operation.

Release Overtravel Condition

Hold the overtravel release button and attempt to jog the axis in the positive direction to clear the alarm.

Listen for grinding or unusual noises indicating binding.

Stop immediately if resistance is felt to avoid damage.

Inspect Axis Path

Visually inspect the axis travel path for debris, tools, or fixtures that may be obstructing movement. Remove any obstructions found.

Check for hidden debris under covers or in hard-to-see areas.

Power down the machine before reaching into the work area.

Check for Mechanical Binding

Manually move the axis (if possible with power off) to feel for binding or excessive resistance. Lubricate or adjust components as needed per the machine manual.

Inspect ballscrews or linear guides for wear or damage.

Do not force movement; escalate if binding persists.