Analisis Preventive Maintenance Mesin Bubut Cnc Berdasarkan Jam Operasi Praktikum Di Laboratorium Cnc Politeknik Negeri Bengkalis

This study analyzes the Preventive Maintenance implementation of an CNC lathe at the CNC Laboratory of Bengkalis State Polytechnic based on practicum operating hours, evaluates the technical condition of key components, determines Maintenance priorities, and develops an operating-hour-based Maintenance schedule. A descriptive-evaluative case-study approach was applied. Primary information was obtained through observation, interviews, documentation, and machine-use records; the workbook reproduced in Appendix 12 contains a simulated dataset used to demonstrate processing of failure, Downtime, temperature, vibration, run-out, backlash, and Alignment records. The estimated machine utilization from January to June 2026 was 540 h, corresponding to ten 50-h intervals, five 100-h intervals, two 250-h intervals, and one 500-h interval for planning purposes. The simulated workbook dataset produced 56.52 h of effective operation, three disturbances, 2.08 h of Downtime, a descriptive MTBF of 18.84 h/event, an MTTR of 0.50 h/repair, and an operational Availability of 96.44%. The maximum temperature rise of the main motor was 18.63 °C above ambient at 2,000 rpm, the maximum vibration was 1.947 mm/s RMS, test-bar run-out reached 0.029 mm, and the maximum backlash values were 0.021 mm on the X-axis and 0.029 mm on the Z-axis; the evaluated Alignment parameters remained below the dataset evaluation limits. The carriage, chuck, Coolant system, and lubrication system were classified as high-priority components. A Preventive Maintenance schedule was therefore developed for every use and at 50, 100, 250, and 500 operating hours, supported by operating logs, condition-monitoring sheets, disturbance histories, checklists, and technical validation.