TL;DR
CMM air bearing contamination causes drag, axis sticking, or erratic motion. Verify the compressed air supply is clean and dry, and check the air filtration before suspecting internal bearing damage.
What you might see
- axis movement feels sticky or dragging on manual operation
- CMM reports axis force fault during automated measurement
- compressed air supply alarm on the CMM
- linear scale readings jump erratically during slow axis motion
Likely causes
Compressed air supply containing moisture, oil aerosol, or particles
CMM air filtration cartridge exhausted not removing contaminants
Air supply pressure below the minimum for the bearing design
Bearing surface contaminated from operating with contaminated air over time
Required tools
- Air pressure gauge (calibrated)
- Replacement inline filter elements (coalescing and particulate)
- Zeiss air supply specification for the installed model
Safety first
- Do not attempt to disassemble air bearing components in the field. CMM air bearings are precision ground surfaces and will be permanently damaged by improper handling.
- Ensure the CMM is parked in its rest position before making any changes to the air supply circuit.
Procedure
- 1
Check the compressed air supply pressure at the CMM inlet. It should be within the range specified by Zeiss for the CONTURA / PRISMO model.[1]
- 2
Inspect the inline coalescing filter and particulate filter at the CMM inlet. Replace filter elements if they have reached the service interval or if the color indicator shows saturation.[1]
- 3
Drain accumulated moisture from the air filter bowl.
- 4
After replacing filters and verifying supply pressure, allow the CMM to run with air bearing pressure for 5 minutes before attempting a qualification or measurement.
- 5
If sticking persists after air quality is confirmed, park all axes at the center of travel and listen for any change in the air-on-bearing sound. Uneven hissing suggests a contaminated bearing surface.
- 6
Air bearing cleaning requires factory-trained service. Do not attempt to clean bearing surfaces in the field. Contact Zeiss service if the issue persists after air quality correction.
Sources
Zeiss Zeiss CONTURA / PRISMO Coordinate Measuring Machine (CMM) general technical documentation, Zeiss
Zeiss CONTURA / PRISMO CMM operator manual, compressed air supply requirements and air bearing maintenance (general)
More guides for Zeiss Zeiss CONTURA / PRISMO
How to fix probe qualification failure on a Zeiss CONTURA / PRISMO CMM
Probe qualification failure means the CMM cannot establish a reliable stylus reference and should not be used for inspection until resolved. Clean the reference sphere and inspect the stylus before re-qualifying.
How to diagnose linear scale reading errors on a Zeiss CONTURA / PRISMO CMM
Linear scale errors cause systematic dimensional errors on all measured features. Clean the scale reader heads and verify the scale strip is free of oil film before concluding a scale or encoder failure.
Stop fixing the same fault twice.
Dovient turns guides like this into your team's shared playbook, with AI that catches recurring issues before they break the line.