Vacuum Gripper Trouble: What to Record Before Robot Service

When a robot's vacuum gripper does not hold a workpiece as expected, the fault may involve the workpiece, suction surface, vacuum generation, settings or another part of the system. A useful service record separates the observed behavior from the suspected cause. It also makes clear which conditions were present when the issue occurred and which tests still need to be performed by qualified personnel.

Describe the handling event

Record the gripper model, robot and controller identifiers, workpiece type and the task underway. Did the system fail to pick up a part, release it unexpectedly, or produce a warning before a transfer? Note the date, time and program or job identifier. If the behavior was intermittent, record how often it was observed and whether it appeared with a particular part or production batch.

Do not continue a potentially unsafe handling operation simply to obtain more examples. Follow the site's stop and escalation procedures. The service provider and responsible site personnel can decide whether a controlled test is appropriate and what safeguards are required.

Record the workpiece and contact surface

Vacuum handling depends on the interface between the gripper and the actual object. Record the workpiece material, shape, surface condition and any openings or contamination that were observed. Describe the gripper's contact area and whether the workpiece was positioned as intended. These observations are leads for investigation, not proof that a particular surface feature caused the fault.

SMC's ZGP vacuum gripper operation manual discusses maintenance, inspection and the relationship between vacuum observations and possible leakage. It applies to the specified product. A service team should consult the manual for the actual gripper, vacuum generator and installation rather than apply one model's settings to another.

Keep pressure readings with their conditions

If the system provides a vacuum or supply-pressure indication, record the value, units, timestamp and whether a workpiece was present. Note where the measurement was taken and whether the display was an instantaneous reading or another reported value. A pressure reading without its context can be difficult to compare with an earlier observation.

Where an approved monitoring system records a history, retain the relevant interval before and after the event and note any gaps in the data. A graph without a scale, unit or timestamp may be misleading. The service provider can compare the record with the equipment's documented operating conditions and decide whether further measurements are needed.

The SMC manual describes how pressure behavior can differ when a workpiece is absent and mentions leakage as one possible interpretation. A single low reading does not establish the location or cause of a leak. The technician needs the relevant equipment, settings and test method to investigate.

Check what changed before the event

Document changes to the workpiece, suction surface, hoses, filters, generator, settings or robot program. Record any recent maintenance and the identifiers of replaced parts. A change that occurred shortly before a problem is worth examining, but it should not be recorded as the confirmed cause without evidence.

SMC's ZXPE5 operation manual gives examples of troubleshooting conditions for that product, including settings, air leakage and testing with an actual workpiece. The relevant checks and service steps depend on the installed model and should be performed according to its instructions.

Plan maintenance safely

A pneumatic or vacuum system can retain energy and a suspended workpiece can create a hazard. Before inspecting or disconnecting components, qualified personnel must follow the site's isolation and support procedures and the applicable manufacturer instructions. Do not loosen hoses, change settings or reach into a robot cell merely to collect a symptom for a service ticket.

Provide the technician with the system layout, relevant readings, photographs of externally visible conditions and the maintenance history. Use an approved process to share logs or configuration files, which may contain production information. The service provider should document which conditions were tested and any limits of the inspection.

Separate a test result from a repair conclusion

After work is performed, record what was inspected, what was changed and how the system was checked. If a test uses a substitute workpiece or different operating conditions, state that explicitly. A successful pickup in a short trial does not establish performance for every part or prove that an intermittent issue has been eliminated.

If the symptom cannot be reproduced, retain the original observations and agree how future occurrences will be reported. For a broader maintenance process, read our inspection and repair approval guide and browse the robot service archive. A clear record helps the service team investigate without turning a pressure reading into an unsupported diagnosis.