Lesson 1Basic CNC program structure and common G-code/M-code elements relevant for verificationThis section introduces basic CNC program structure, key G and M codes, and how to read blocks, comments, and tool calls so operators can verify programs for safety, correct motion, and compatibility with the setup in local manufacturing environments.
Program header, safety lines, and commentsTool call, spindle speed, and coolant commandsLinear and circular motion G-code essentialsWork coordinate systems and tool length offsetsCommon M codes for spindle, coolant, and program endLesson 2Actions for abnormal conditions found during pre-start (tagging, notifying, isolating, initiating maintenance)This section defines proper responses to abnormal pre-start findings, including tagging, isolating, notifying responsible personnel, and initiating maintenance, while preventing unsafe bypasses or unauthorized repairs in industrial settings.
Recognizing critical versus minor abnormalitiesApplying tags and documenting out-of-service statusIsolating energy sources when hazards are presentNotifying supervisors and maintenance promptlyRecording issues in logs or digital systemsLesson 3Mandatory PPE for CNC work and rationale (eye protection, hearing protection, cut-resistant gloves, aprons, safety shoes)This section details required PPE for CNC milling, why each item is needed, and how to select, inspect, and use it correctly, linking hazards such as chips, noise, and sharp edges to specific protective equipment for worker safety.
Eye and face protection for chips and coolant splashHearing protection selection for shop noise levelsCut-resistant gloves for handling tools and stockProtective clothing, aprons, and sleeves near rotating partsSafety footwear for impact and slip protectionLesson 4Common lockout/tagout procedure steps applied to CNC machines (isolation, verification, documentation)This section outlines typical lockout/tagout steps for CNC machines, including energy isolation, dissipation, verification, and documentation, stressing coordination with maintenance and compliance with site procedures in Botswana.
Identifying all CNC energy sources and pointsShutting down machine using normal stop sequenceApplying locks, tags, and group lockout devicesVerifying zero energy and tryout of controlsRestoring energy and removing locks safelyLesson 5CNC milling machine components and control interface (spindle, axis drives, tool changer, coolant, PLC/HMI)This section explains main CNC milling components and the control interface, showing how spindle, axes, tool changer, coolant, PLC, and HMI interact, and how operators use screens, keys, and modes safely in daily operations.
Spindle assembly, drive, and speed controlLinear axes, ball screws, and feedback systemsAutomatic tool changer and tool magazine basicsCoolant delivery, chip evacuation, and guardingHMI screens, soft keys, and mode selectionPLC safety logic, interlocks, and status lightsLesson 6Machine-specific safety hazards (entanglement, flying chips, tool breakage, coolant exposure, electrical risks)This section reviews machine-specific CNC hazards such as entanglement, flying chips, tool breakage, coolant exposure, and electrical risks, and links each hazard to preventive measures and safe work practices for local industries.
Entanglement risks from rotating tools and partsFlying chips and high-velocity particle hazardsTool breakage causes and containment methodsCoolant mist, skin contact, and ventilation needsElectrical shock and arc risks around CNC cabinetsLesson 7Daily and shift inspection items for CNC (tool wear, spindle runout, coolant level, chip evacuation)This section defines daily and shift inspection items such as tool wear, spindle runout, coolant level, and chip evacuation, showing how routine checks prevent failures, improve finish, and support stable production in factories.
Visual inspection of guards, doors, and panelsChecking tool wear, chipping, and pull stud conditionMonitoring spindle noise, heat, and basic runoutCoolant level, concentration, and contamination checksChip conveyor, augers, and filter cleanlinessLesson 8Verifying guards, interlocks, and emergency stops on CNC machinesThis section focuses on verifying guards, interlocks, and emergency stops, explaining test methods, acceptance criteria, and documentation so operators can confirm that safety systems function before and during use in Botswana.
Types of fixed, movable, and interlocked guardsTesting door interlocks and safety switchesVerifying emergency stop buttons and circuitsConfirming light curtains or area scannersDocumenting safety device tests and findingsLesson 9CNC pre-start checklist: mechanical, electrical, tooling, workholding and coolant system checksThis section covers a structured CNC pre-start checklist, including mechanical, electrical, tooling, workholding, and coolant checks, emphasizing documentation, repeatability, and early detection of unsafe or abnormal conditions.
Visual walkaround and housekeeping verificationMechanical axis travel and limit stop checksElectrical panels, indicators, and cable conditionTooling integrity, clamping, and offset confirmationWorkholding security and part location verificationCoolant level, concentration, and flow path checks
