A lathe machine is the cornerstone of any machine shop. When shopping for a used lathe, whether manual or CNC, a thorough physical inspection is necessary to ensure you are not buying a machine that will require expensive rebuilds. Here is our expert guide on inspecting a pre-owned lathe.
Step 1: Check the Bed Ways for Wear
Inspect the induction-hardened bed ways, particularly near the headstock where the carriage spends most of its time. Look for ridge wear, deep scratches, or scoring. Running a carriage over worn bed ways will result in tapers being cut on long parts.
Step 2: Spindle Bearing Tolerances
Mount a dial indicator to the bed and place the pointer on the spindle nose. Apply physical pressure to the spindle chuck to check for axial and radial play. Any movement greater than a few microns indicates the spindle bearings need adjustment or replacement.
Step 3: Gearbox and Feed Inspections
Run the lathe through all speed ranges. Listen for loud grinding or clashing gears in the headstock, which points to chipped teeth. Engage the lead screw and feed rods to ensure the feed carriage travels smoothly in all directions.
Taking these inspection precautions helps guarantee that your pre-owned lathe will produce concentric, accurate turned parts immediately upon delivery.