Problems on this page:
Results not repeatable
Hits OEE: Quality
Symptoms: Measuring the same part twice gives different results.
Room temperature changing
Keep the measuring room at a steady temperature and let parts soak to room temperature first.
Part not held firmly
Use a fixture that holds the part without distorting it.
Probe not qualified after a change
Qualify the probe after every stylus change.
Dirt on the part or stylus tip
Clean the part and the stylus before measuring.
Prevention: Repeatability checked with a reference part on a fixed schedule.
Probe qualification failing
Hits OEE: Quality
Symptoms: Probe qualification gives a large error or fails.
Stylus loose or damaged
Check the stylus is tight and the tip is undamaged.
Reference sphere dirty or loose
Clean the sphere and check it is firmly mounted.
Wrong stylus data in the software
Check the stylus definition matches the one fitted.
Probe damaged in an earlier collision
Have the probe checked if it was in a crash.
Prevention: Qualification results logged per stylus.
Machine colliding with the part
Hits OEE: Availability
Symptoms: The probe hits the part or fixture during a programme.
Part alignment wrong at the start
Check the manual alignment step before running the programme.
Fixture changed since the programme was written
Update the programme or put the fixture back as it was.
Clearance moves too tight
Raise the clearance plane in the programme.
Programme edited without a dry run
Run edited programmes slowly first.
Prevention: Collisions recorded with their cause.
Air bearing alarm
Hits OEE: Availability
Symptoms: The machine stops with an air pressure or air bearing alarm.
Supply pressure low
Check the compressed air supply pressure at the machine.
Oil or water in the air
Check the filters and dryer on the air supply.
Filter element blocked
Replace the machine air filter.
Air leak in the machine pipework
Have leaks found and repaired.
Prevention: Air filters on the machine checked weekly.
Results disagree with other gauges
Hits OEE: Quality
Symptoms: The CMM passes parts that the line gauge fails, or the other way round.
Different datums or alignment
Check that both use the datums on the drawing.
Different measuring method
Compare the number and position of points each method uses.
One of the instruments out of calibration
Check the calibration status of both.
Part temperature different at each gauge
Measure both at the same part temperature.
Prevention: Correlation study run when a new programme or gauge is introduced.
Measuring cycle too slow
Hits OEE: Performance
Symptoms: Parts wait at the CMM and production waits for results.
Programme takes more points than needed
Review the programme against what the drawing actually needs.
Slow moves between features
Optimise the path and the move speeds.
Manual alignment every time
Use a fixture with a stored alignment.
Stylus changes during the programme
Group features by stylus.
Prevention: Cycle time per programme recorded.
Axis or scale error
Hits OEE: Availability
Symptoms: The machine stops with a scale or axis error.
Scale dirty or contaminated with oil
Have the scales cleaned as the maker describes, without touching the scale surface.
Read head misaligned after a knock
Have the read head alignment checked by the service provider.
Cable worn in the cable chain
Check the cable chains for worn or pinched cables.
Controller fault
Read the controller error log and give it to the service provider.
Prevention: Machine guarding and covers checked so dust cannot reach the scales.
Temperature compensation errors
Hits OEE: Quality
Symptoms: Results drift with the time of day.
Part temperature sensor not used or faulty
Check the part sensor and that compensation is switched on.
Machine temperature sensors faulty
Have the machine sensors checked.
Parts measured straight from the line while warm
Let parts reach room temperature.
Sunlight or heaters near the machine
Shield the machine from direct heat.
Prevention: Room temperature logged beside the machine.
Calibration overdue
Hits OEE: Quality
Symptoms: The machine is used past its calibration date.
No reminder in the maintenance system
Add the calibration due date to the maintenance or quality system with an advance warning.
Calibration postponed for production
Book the calibration into the production plan like any other planned stop.
Certificate not filed after the visit
File certificates where quality and auditors can find them.
Interim checks not done between calibrations
Run interim checks with a reference artefact so a problem is found before the next calibration.
Prevention: Calibration status visible on the machine.
Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.
Related equipment guides: CNC machine · lathe · surface grinder · vision inspection · EDM machine · leak tester
Stop the same fault coming back
Recurring coordinate measuring machine stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.
Book a Fabrico demo
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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary
Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover