Selecting appropriate tools, equipment and processes · Designing and making principles
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The manufacturing process
The required scale of production affects how a product is manufactured.
One-off production
A single product is made, often for a particular client. Skilled workers can use flexible tools and adjust individual components during manufacture.
Batch production
A set number of identical products is manufactured. Jigs, fixtures and templates can reduce repeated marking out and improve speed, consistency and accuracy.
Mass production
Very large quantities of standardised products are manufactured, often using dedicated tooling, automated machinery and organised production lines. Initial setup costs can be high, but unit cost can fall when large quantities are produced.
Effect of increasing production quantity
A process suitable for a prototype or one-off product may be too slow or expensive for large quantities. Moving to batch or mass manufacture can therefore require:
dedicated tooling, jigs or fixtures
greater automation
standardised components
tighter process control
planned quality-control checks
changes to the product so it can be manufactured and assembled efficiently.
Tool, equipment and process selection must match the material, operation, required accuracy and safety risk.Vacuum forming: a heated thermoplastic sheet is drawn over a former and held while it cools.Injection moulding: granules are melted and driven by a screw through a nozzle into a closed mould.Extrusion forces softened material through a shaped die to produce a continuous cross-section.Blow moulding: air expands a hot polymer parison against the inside of a mould.Rotational moulding coats the inside of a heated rotating mould before the hollow product cools.Compression moulding uses heat and pressure to form a measured charge inside a mould.A pattern forms a cavity in sand before molten metal is poured, cooled and removed.Die casting injects molten metal into a reusable metal die under pressure.Investment casting forms a ceramic mould around a sacrificial pattern for detailed components.MIG welding feeds a consumable wire electrode into a gas-shielded weld pool.TIG welding uses a non-consumable tungsten electrode and separate filler where required.Spot welding clamps sheet between electrodes and creates localised heat through electrical resistance.Steam softens lignin so timber can be bent around a former and held until dry.Thin veneers are glued and clamped around a former to create strong curved components.Flexography uses a relief plate and rollers to transfer ink to the substrate.Offset lithography transfers the image from plate to blanket cylinder and then to the substrate.Screen printing pushes ink through open areas of a mesh stencil onto the substrate.A focused laser follows a programmed path while assist gas helps clear the cut.Milling removes material with a rotating multi-point cutter while the work is accurately positioned.In turning, the workpiece rotates while a cutting tool removes material to create cylindrical forms.FEA divides a model into elements so stresses and deformation can be calculated.CFD predicts how fluids move around or through a product.A go/no-go gauge quickly checks whether a feature lies within its permitted tolerance.Vernier callipers measure external, internal and depth dimensions accurately.A micrometer uses a precision screw to measure small dimensions accurately.A tensile test records how a standard specimen responds as an increasing axial load is applied.Hardness tests compare resistance to permanent indentation under controlled conditions.Anthropometric data provides measured human dimensions for designing appropriate product sizes and clearances.Ergonomics applies knowledge of people to improve comfort, safety, usability and performance.Bauhaus design favoured functional forms, modern materials and design suited to industrial production.Art Deco is recognisable through geometric decoration, symmetry, luxury materials and machine-age influence.Memphis challenged restrained modernism with bold colour, pattern, geometry and playful forms.Arts and Crafts valued skilled making, natural inspiration, material honesty and resistance to poor-quality mass production.The life-cycle model helps explain how sales, competition and redesign priorities change over time.Sustainable design decisions should reduce resource use and keep products and materials useful for longer.
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