Lesson 1Key process steps: setup, roughing, finishing, inspection, deburring, cleaningThis section decomposes the CNC process into key steps: setup, roughing, semi‑finishing, finishing, deburring, cleaning, and inspection, clarifying objectives, inputs, outputs, and typical equipment or documentation 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 needed before redesign, such as demand volumes, batch sizes, order variability, supplier lead times, floor space, staffing, skills, and shift patterns, to ensure realistic process improvement options.
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 aluminum housings from billet to finished partThis section traces the full workflow for precision aluminum housings, from billet receipt through programming, setup, roughing, finishing, inspection, and shipping, highlighting information flow, handoffs, and typical documentation 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 aluminum housing characteristics, including envelope sizes, wall thickness ranges, tolerance bands, flatness and position requirements, surface finish targets, and how these assumptions influence process selection and risk.
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 issues in CNC aluminum housings, including tolerance stack‑ups, form and position errors, surface damage, burr formation, residual stresses, and coolant‑related contamination that can drive 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 utilization, cycle inefficiencies, long setups, tool life, material removal ratesThis section identifies drivers of high cost and long lead time, such as poor machine utilization, long non‑cutting time, inefficient toolpaths, extended setups, conservative cutting data, tool life problems, and unbalanced material removal strategies.
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 primary manufacturing metrics for CNC housings, including cycle time, takt, throughput, scrap, rework, first‑pass yield, cost per part, and capacity utilization, and explains how to measure and interpret each indicator.
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 used for aluminum housings, linking equipment choices to rigidity, accuracy, thermal control, uptime, and maintainability.
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
