Lesson 1Key process steps: setup, roughing, finishing, inspection, deburring, cleaningThis section breaks down the CNC process into main steps: setup, roughing, semi-finishing, finishing, deburring, cleaning, and inspection, explaining objectives, inputs, outputs, and typical equipment or documents at each stage.
Pre‑setup staging and job preparationMachine setup and workholding verificationRoughing operations and bulk removalSemi‑finishing and feature definitionFinishing, chamfering, and edge qualityDeburring, cleaning, and final inspectionLesson 2Data to gather before redesign: volumes, batch size, order variability, supplier lead times, floor space and workforce capabilitiesThis section lists the operational data required before redesign, such as production volumes, batch sizes, order variations, supplier delivery times, available floor space, staffing, skills, and shift schedules, to ensure practical process improvement choices.
Demand volumes and product mixBatch sizes, lot sizing, and changeoversOrder variability and demand patternsSupplier lead times and reliabilityAvailable floor space and layout limitsWorkforce skills, shifts, and flexibilityLesson 3Typical workflow for precision aluminium housings from billet to finished partThis section traces the full workflow for precision aluminium housings, from receiving the billet through programming, setup, roughing, finishing, inspection, and dispatch, highlighting information flow, handovers, and typical documents used.
Billet specifications and incoming inspectionCAM programming and process planningSetup, workholding, and zero referencingRoughing strategies and toolpath selectionFinishing passes and in‑process checksFinal inspection, packaging, and shippingLesson 4Typical part assumptions: sizes, wall thicknesses, tolerances, surface finish requirementsThis section defines typical characteristics of aluminium housings, including overall sizes, wall thickness ranges, tolerance limits, flatness and position specs, surface finish goals, and how these assumptions affect process choice and risks.
Common housing sizes and aspect ratiosWall thickness ranges and stiffness limitsDimensional and geometric tolerance bandsFlatness, perpendicularity, and positionSurface finish and cosmetic class levelsCritical features and datum structuresLesson 5Quality issues and failure modes: geometric tolerance stack-up, surface integrity, burrs, residual stress, coolant contaminationThis section reviews common quality problems in CNC aluminium housings, including tolerance stack-ups, form and position errors, surface damage, burrs, residual stresses, and coolant contamination that lead to rework, scrap, and field failures.
Dimensional errors and tolerance stack‑upsForm, position, and runout nonconformanceSurface integrity, chatter, and tool marksBurr formation, removal, and missed edgesResidual stress, distortion, and warpageCoolant contamination and cleanliness risksLesson 6Root causes of high cost and lead time: machine utilisation, cycle inefficiencies, long setups, tool life, material removal ratesThis section identifies reasons for high costs and long lead times, such as poor machine utilisation, extended non-cutting time, inefficient tool paths, lengthy setups, conservative cutting parameters, tool wear issues, and unbalanced material removal.
Machine utilization and OEE shortfallsCutting vs non‑cutting time breakdownSetup duration, changeovers, and SMEDTool life limits and unplanned breakageMaterial removal rates and chip loadScheduling, queues, and waiting lossesLesson 7Primary manufacturing metrics to collect: cycle time, takt, throughput, scrap, first-pass yield, cost-per-partThis section defines key manufacturing metrics for CNC housings, including cycle time, takt time, throughput, scrap, rework, first-pass yield, cost per part, and capacity utilisation, and explains how to measure and analyse each one.
Cycle time components and measurementTakt time, demand, and line balancingThroughput, WIP, and bottleneck analysisScrap, rework, and defect categorizationFirst‑pass yield and rolled throughputCost per part and cost driver breakdownLesson 8Common machine types, tooling, fixturing, coolant and chip managementThis section surveys common CNC machine types, tooling, fixturing, coolant systems, and chip management methods for aluminium housings, linking equipment choices to rigidity, accuracy, thermal stability, uptime, and maintenance.
3‑axis vs 5‑axis machining center choicesSpindles, holders, and aluminum toolingWorkholding, vises, and custom fixturesCoolant types, delivery, and filtrationChip evacuation, conveyors, and binsMaintenance and reliability considerations
