Feed-roll condition affects both traction and the surface of the strip. Look for deposited material, embedded particles, scoring, uneven contact and recurring marks on representative stock. Record where the mark occurs and whether it repeats; this is more useful than describing the entire feeder as “dirty.”

Clean stock-contact surfaces only with the method and products approved for the roll finish and material. The manuals’ references to gear lubrication do not mean that oil or grease should be applied to the stock-contact feed rolls. Likewise, an upstream stock-lubrication process should not be confused with maintenance lubrication of bearings or gears.

• Rolls and guides: check contamination, wear, damage and signs that the strip is rubbing or being forced sideways.
• Drive and fastening: qualified personnel check the specified lubrication points, debris, retention and visible damage under the approved isolation procedure.
• Alignment: compare roll parallelism, support and guide condition with the applicable service limits rather than adjusting by appearance alone.

If slipping or surface marking remains after cleaning, record the material, operating condition and symptom. Increasing clamping pressure is not a universal remedy. The feed slipping and material pullback guide distinguishes roll contact problems from upstream load and material-path effects.

Check the condition and response of the operator display, buttons, switches and indicators through the approved operating checks. Record a sticking button, unreadable display, damaged enclosure or intermittent indication rather than working around it.

Cabinet contamination and restricted ventilation deserve their own maintenance entries. Check the fitted vents and filters for dust or oil buildup and keep their service schedule consistent with the environment. Do not direct compressed air into energized equipment or use an unapproved cleaning method that pushes contamination onto electrical components.

Qualified electrical personnel should inspect external wiring, cable protection, connections and applicable relay or timing-switch components according to the machine’s electrical documentation. An article cannot supply universal acceptance values or a safe live-testing procedure. Damaged insulation, loose components, overheating evidence or repeated electrical faults require a controlled service response.

Before changing anything, preserve the alarm text, operating mode and relevant settings. Do not change servo parameters or erase a program simply to make a maintenance warning disappear.

A checklist is useful only if it changes what happens next. Record the exact location and observed symptom, attach a clear photograph where helpful, and identify who will assess the finding. Use “acceptable,” “not applicable,” “service required” or “not inspected” so an unchecked item cannot silently become a pass.

Hold the affected equipment for authorized review when there is damaged wiring, a cracked or loose mechanical component, loss of release function, an unresolved abnormal noise, or a failed protection check. The response depends on the hazard and approved plant procedure; do not continue production merely because the feeder can still move.

For a feeding symptom, preserve the commanded length, measured result, material details and when the error appeared. The NC servo feeder error diagnostic guide helps distinguish consistent error from irregular error. That distinction helps the service team avoid replacing parts before identifying the cause.

“Cleaned and lubricated” describes work performed, not an acceptance result. Before maintenance starts, retain the approved setup baseline and the part or strip characteristics that will be checked afterward. Record any authorized change to that baseline.

1. Confirm the setup: correct material, tooling, program and feed length; include active stages, repeats and counter state where applicable.
2. Restore the equipment: verify guards, connections, mounting, stock guides and the material path under the approved return-to-service procedure.
3. Verify the sequence: check feed completion, release, re-clamping, relevant signals and protection functions through safeguarded, controlled checks.
4. Measure the result: compare delivered pitch, strip tracking, surface condition and representative part results with the agreed acceptance criteria.
5. Authorize release: record the trial conditions, measurements, remaining exceptions and the person approving the return to production.

A satisfactory slow trial does not automatically confirm operation at the intended production rate. Use the agreed acceptance plan and the NC feeder commissioning guide for the broader verification framework. For a changing-length job, verify the entire sequence described in the multi-step NC feeding guide, not only the first programmed move.