Machine tool maintenance
Inspection and care to keep machines accurate and in service for a long time, organized by machine type. Compiled with sources from machine makers' instruction and maintenance manuals, materials from chuck, bearing and lubricant makers, and from standards and regulations. Intervals and oil types differ from machine to machine, so finally check the manual for your own machine.
Heat, noise, oil level.
Small changes every day
are signs of a failure!
By machine type
Lathes
Before-start-up checks through annual checks of manual lathes and CNC lathes, lubrication, chuck care, accuracy checks and common problems.
✓Machining centers
Daily through annual checks of vertical and horizontal machining centers, lubrication, tool holders, spindle taper and drawbar force, accuracy checks (ballbar, etc.) and common problems.
✓Grinding Machines
Inspection of surface, cylindrical, internal and centerless grinders; wheel surface speed, flanges, balance and dressing; test running and special training (Japan); troubleshooting chart for grinding problems.
✓Gear Cutting Machines
Inspection of hobbing machines, gear shapers and similar machines; fire prevention for non-water-soluble cutting oil; care of hobs and pinion cutters (shifting, regrinding, spacing error); troubleshooting chart for gear problems.
✓汎用フライス盤
ひざ形の立て, 横フライス盤とタレット形フライス盤の点検, ワンショット給油, ジブ, アーバ, 主軸頭の手入れ, トラミング (主軸の直角出し), 不調の早見表。
EDM machines, band saws, drill presses, presses and more will be added in turn.
Checks and calculations common to all machines
Coolant Management
Calculate concentration from a refractometer reading and factor, and the amounts of concentrate and water needed to return to a target concentration. Also pH, signs of spoilage, and inspection frequency.
🛢Lubricating oil and grease
A calculator that looks up the ISO VG kinematic viscosity range at 40 °C, oil types and VG for machine tools, how to choose hydraulic fluid, and NLGI grease grades.
🌡Thermal growth
Calculates elongation from length, temperature difference and coefficient of linear expansion. Guide values for ball screw elongation, causes of thermal displacement in machine tools and countermeasures.
📷Inspection with a thermal camera
Cautions on emissivity, what to look at in electrical equipment and motors, guide values for judging temperature differences, and how to compare with images from normal operation.
↻Bearing and ball screw life
Calculates bearing L10 life in hours, and ball screw life in hours and travel distance, from basic dynamic load rating, load and speed. Load factors and guide values for required life.
〰Vibration evaluation
Judges ISO 10816-3 zones A to D from the RMS vibration velocity. Relative judgment by the ratio to the normal value, and how to choose measurement points.
⚡Insulation resistance
Judges pass or fail against the low-voltage circuit standard values (0.1/0.2/0.4 MΩ) from the working voltage and the measured value. How to choose the test voltage and how to measure.
🎓Machine Maintenance Skill Test (Japan)
Grades and tasks of the national skills test "Machine Maintenance" (Japan), exam format and subjects, practical experience required to take the exam, and passing criteria.