Lesson 1Key process steps: setup, roughing, finishing, inspection, deburring, cleaningWe break down the CNC work into important stages like preparing the machine, removing rough material, smoothing it out, checking for errors, removing extra bits, and cleaning. Each stage has clear aims, what goes in, what comes out, and usual tools or papers used in Eritrean workshops.
Preparing materials before setup and job readinessSetting up the machine and checking how parts are heldRough cutting to remove big pieces of materialSemi-finishing to shape main featuresFinal smoothing, edge rounding, and surface qualityRemoving burrs, cleaning, and last checksLesson 2Data to gather before redesign: volumes, batch size, order variability, supplier lead times, floor space and workforce capabilitiesBefore changing the process, we need to collect key work data like how much is needed, batch sizes, changes in orders, time from suppliers, space on the floor, number of workers, their skills, and work shifts. This helps make sure improvements fit real needs in local settings.
Amounts needed and types of productsBatch sizes, how to group lots, and switching tasksChanges in orders and patterns of demandTime from suppliers and how reliable they areSpace available on the floor and layout issuesSkills of workers, shifts, and how flexible they can beLesson 3Typical workflow for precision aluminum housings from billet to finished partWe follow the full path for making precise aluminum casings, starting from getting the raw billet, planning the program, setting up, rough cutting, finishing, checking, and sending out. We point out how information moves, handovers between people, and usual papers used in the process.
Specs for billets and checks when they arriveComputer planning and step-by-step process designSetup, holding parts, and setting reference pointsWays to rough cut and choose tool pathsFinal cuts and checks during the workLast checks, packing, and shippingLesson 4Typical part assumptions: sizes, wall thicknesses, tolerances, surface finish requirementsWe describe common features of aluminum casings, like overall sizes, thickness of walls, allowed errors in size, flatness and position needs, targets for surface smoothness, and how these choices affect picking the process and spotting risks in production.
Usual sizes and shapes of casingsRanges for wall thickness and strength limitsAllowed errors in size and shapeFlatness, straight angles, and position needsSmoothness of surface and appearance levelsKey parts and reference pointsLesson 5Quality issues and failure modes: geometric tolerance stack-up, surface integrity, burrs, residual stress, coolant contaminationWe review common problems with quality in CNC aluminum casings, like errors building up in sizes, mistakes in shape and position, damage to surfaces, extra bits forming, stresses left in the metal, and dirt from coolant that can cause redoing work, waste, or failures later.
Errors in size and how they add upShape, position, and wobble not meeting standardsSurface strength, shaking marks, and tool scratchesHow burrs form, how to remove them, and missed spotsStress left, bending, and warpingDirt from coolant and risks to cleanlinessLesson 6Root causes of high cost and lead time: machine utilization, cycle inefficiencies, long setups, tool life, material removal ratesWe find the main reasons for high costs and long waits, like machines not used well, too much time not cutting, poor tool paths, long setup times, careful cutting speeds, problems with tools lasting, and uneven ways to remove material.
How well machines are used and shortfalls in efficiencyTime cutting versus time not cuttingTime for setup, switching, and quick change methodsLimits on tool life and sudden breaksRates of removing material and chip sizePlanning, waiting lines, and losses from delaysLesson 7Primary manufacturing metrics to collect: cycle time, takt, throughput, scrap, first-pass yield, cost-per-partWe explain main measures for making CNC casings, like time per cycle, takt time, output rate, waste amount, rework, success on first try, cost per piece, and how well capacity is used. We show how to measure and understand each one.
Parts of cycle time and how to measure themTakt time, demand, and balancing the lineOutput, work in progress, and narrow pointsWaste, rework, and types of defectsSuccess on first pass and overall outputCost per piece and what drives costsLesson 8Common machine types, tooling, fixturing, coolant and chip managementWe look at usual CNC machines, tools, ways to hold parts, coolant systems, and handling chips for aluminum casings. We connect choices of equipment to strength, accuracy, heat control, uptime, and ease of keeping them working.
Choices between 3-axis and 5-axis machine centersSpindles, holders, and tools for aluminumHolding work, vises, and special fixturesTypes of coolant, how it's delivered, and cleaning itRemoving chips, using conveyors, and storage binsKeeping up maintenance and reliability
