110

Check counterbalance pressure

Access DIAGNOSTICS > PNEUMATICS and verify counterbalance pressure reads 80-90 PSI. Low pressure indicates cylinder or valve failure.

Ensure spindle is retracted and Z-axis is supported before checking counterbalance system

Test counterbalance operation

In MDI mode, jog Z-axis up and down slowly (F10). Movement should be smooth without jerking or binding that indicates counterbalance issues.

Listen for air leaks around counterbalance cylinders during movement

Verify counterbalance adjustment

With spindle at mid-travel, the Z-axis should hold position when servo is disabled via DIAGNOSTICS > SERVOS. Drift indicates improper counterbalance.

Only disable servos with spindle properly supported

Inspect Z-axis ways and covers

Remove way covers and inspect for chip buildup, damaged wipers, or scoring on the ways. Clean with way oil and lint-free cloths.

Lock out power and use proper lifting equipment when accessing Z-axis components

Check ballscrew condition

Manually rotate Z-axis ballscrew (power off) and feel for rough spots, binding, or excessive play that indicates wear or contamination.

Use a dial indicator on the ballscrew to check for runout - should be less than 0.0005 inches

Verify lubrication system

Check automatic lubrication system operation via DIAGNOSTICS > LUBRICATION. Ensure proper oil flow to Z-axis components and reservoir levels.

Never operate machine with insufficient lubrication

Check servo motor current draw

Access CURRENT COMMANDS/POSITION and monitor Z-axis current during slow jogging. Compare to nameplate ratings and other axes for abnormal readings.

Normal Z-axis current should be 2-4 amps during light jogging with counterbalance working

Inspect motor connections

Check all Z-servo motor connections for corrosion, looseness, or damage. Verify encoder cable connections are secure and undamaged.

Disconnect power before inspecting electrical connections

Test servo drive parameters

Verify parameter 71 (Current Limit) is set correctly for your Z-servo motor. Check parameter 72 (Current Limit Time) for proper I²T timing.

Factory default for parameter 71 is typically 150% of motor rating

Review program feed rates

Check G-code for excessive Z-axis feed rates (F values) during plunge cuts or rapid positioning that may overload the servo system.

Z-axis feed rates should typically not exceed 200 IPM for most operations

Analyze cutting parameters

Verify depth of cut and tool geometry are appropriate for material. Excessive DOC forces high Z-axis loads during retraction.

Always follow tool manufacturer's recommended cutting parameters

Check acceleration settings

Review parameters 75-77 (acceleration limits) to ensure Z-axis acceleration isn't set too aggressively for the mechanical system.

Reduce parameter 77 (Z-axis acceleration) by 10-20% if overloads occur during rapid moves

Check servo gain parameters

Access SETTINGS > PARAMETERS and verify Z-axis servo gains (parameters 80-85) match factory specifications for your machine model.

Only qualified technicians should modify servo gain parameters

Monitor following error

Use CURRENT COMMANDS/POSITION to observe Z-axis following error during movement. Excessive error indicates tuning problems.

Following error should typically be less than 0.001 inches during normal operation

Reset to factory defaults

If parameters have been modified, restore Z-axis servo parameters to factory defaults and test operation before making adjustments.

Document all parameter changes before resetting to factory defaults