How to inspect a used Okuma lathe

I. Static Inspection of Used Okuma Lathe

Overall Appearance and Maintenance Condition:

Observation: Check for obvious bumps, damage, or repair marks on the machine body. Severe corrosion, especially on the guide rails and lead screw, is a major hidden danger.

Cleanliness: Open the protective cover and observe the internal debris and oil stains. Excessive dirt may indicate poor maintenance by the previous owner.

Inquiry History: Understand the machine tool's usage background (24-hour continuous production or intermittent use?), processed materials (has it been used to process castings or hard materials?), and reasons for idleness.

Key Mechanical Component Inspection:

Guide Rails and Lead Screws: This is the machine tool's "lifeline." Touch the surface of the guide rails and lead screws to feel for obvious wear pits or scratches. Slight, uniform wear is acceptable, but any "biting" indicates the need for major overhaul.

Spindle Box: Check for oil leaks. Manually rotate the spindle to check for smoothness and abnormal noises.

Tailstock: Check if the sleeve extension and retraction are smooth and the locking is reliable.

II. Dynamic Inspection: Core Performance Test (Must have a test cut with material)

Dry Run Test:

Listen to the sound: During the spindle speed change from low to high, carefully listen for any abnormal impact sounds, friction sounds, or continuous sharp noises from the spindle box and drive system. The sound should be smooth and even.

Observe the movement: Test the accuracy, speed, and lack of impact of the turret's indexing and locking. Test the smooth and proper movement of all pneumatic/hydraulic components, including the tailstock, sleeve, and chuck.

Accuracy and Function Test:

Spindle Accuracy: Use a dial indicator to check the spindle's radial runout and axial movement. Okuma machine tool standards are typically very high; radial runout should be better than 0.005mm.

Geometric Accuracy: Cutting a test piece is the only reliable inspection method.

Turning the outer diameter: Check cylindricity and dimensional accuracy.

Turning the end face: Check flatness.

Boring: Inspect the coaxiality and surface finish of the hole.

Use qualified measuring tools to measure the test piece. Compare the data with the values ​​displayed on the machine tool screen to identify potential problems such as lead screw backlash.

III. CNC System and Electrical Inspection

Okuma OSP System Inspection:

Screen and Buttons: Check if all buttons and knobs are sensitive and effective, and if the screen display is complete and without defects.

Check Alarm History: Access the system backend and check for frequent or unresolved historical alarm records. This can reveal hidden faults.

Functional Testing: Test if all G-codes, M-functions, user macro programs, etc., execute normally.

Parameters and Backup: Ensure the seller can provide a complete backup of system parameters that matches the machine tool. This is the "soul" of the machine tool; its absence will cause the machine to malfunction.

Electrical Cabinet Inspection:

Open the electrical cabinet and observe for signs of overheating (burnt marks), component replacement, wiring modifications, etc. Smell for any burnt odor.