How do I inspect a used Newway machine?

Author:J           Date:2025-11-05

Phase 1: Document and History Verification

Before making any payment, a document audit will be conducted first:

Technical Files: Request the used newway's instruction manual, electrical schematics, PLC program, and parameter tables. Complete documentation is invaluable for future maintenance; missing documents indicate high risk.

Maintenance Records: Inquire about and review past maintenance records, paying particular attention to the repair or replacement history of core components such as the spindle, guide rails, and ball screws.

Certificate of Conformity and Precision Inspection Sheet: Confirm the original factory precision standard of the equipment with the seller as a benchmark for subsequent acceptance.

Phase 2: Static and Functional Inspection

Structural Inspection: Carefully inspect the bed, column, crossbeam, and other major basic components for cracks, repairs, or irreversible corrosion.

Core Component Wear: Open the protective cover and inspect the wear of the guide rails and ball screws. Slight, uniform wear is acceptable, but deep grooves, dents, or rust indicate significant repair costs.

Functional Completeness Test: After power-on, test all auxiliary functions one by one to ensure they function properly, including:

The Automatic Tool Changer (ATC) tool changing process: Is it smooth, accurate, and impact-free?

The spindle tool release/pull mechanism: Is it reliable?

The cooling system, hydraulic system, and lubrication system: Are they functioning properly and without leaks?

The limit switches and safety interlock devices for each axis: Are they effective?

Third Stage: Dynamic and Precision Verification – “Accuracy in Motion”

This is the core of acceptance testing and must be performed on-machine:

No-load Run Noise Troubleshooting: Run the X, Y, and Z axes at different speeds throughout their full stroke, carefully listening for any abnormal vibrations or noises from the drive components.

Spindle Warm-up Test (Critical): Run the spindle continuously at its highest speed or commonly used high speed for at least 30 minutes. Immediately afterwards, use an infrared thermometer to measure the temperature rise of the spindle bearings. The temperature rise should be stable, and the maximum temperature should not exceed 60-70℃; otherwise, it indicates poor bearing condition.

Precision Inspection (Trial Cutting): This is the final and irreplaceable acceptance step.

Heavy Cutting Test: Perform large depth-of-cut, high-feed milling on a steel workpiece to test the machine tool's rigidity and stability under load, observing for vibration or "jamming."

Finishing Test: Finish mill a typical workpiece (such as a square cavity or inclined surface), then use a laser interferometer to test the positioning accuracy and repeatability of each axis, and use a ballbar to test the machine tool's roundness error and servo matching performance. If specialized instruments are unavailable, a third party must be commissioned to conduct a comprehensive inspection of the workpiece using a coordinate measuring machine to ensure that its dimensions and geometric tolerances meet your production requirements.

Fourth Stage: Final Negotiation and Delivery

Based on the above acceptance results, you will be in a position of absolute control:

Problem Listing: Compile all discovered problems, from minor faults to precision deviations, into a detailed list.

Negotiation and Price Negotiation: Use this list as a basis to conduct final price negotiations with the seller, or request that they complete specific repairs before delivery.

Final payment and warranty: Try to pay a portion of the final payment, and then pay the remaining balance after the equipment has been running stably for a period of time. At the same time, try to request the seller to provide a short-term warranty commitment for a certain period of time.

More Articles