Additive Techniques

Are manufacturing techniques that add material in order to create a product or component.

3D printing has rapidly advanced and become affordable which has resulted in the ability to have a 3D printers at home.

• Consumers can download plans for products from the internet and print these products themselves.
• Simple CAD software is more understandable these days so consumers can design and print custom parts.

Paper-based rapid prototyping

https://www.youtube.com/watch?v=LafffSXHNFY

• It lays sheets of regular office paper and cuts out the shapes.
• Description from Medium
• Materials used:  ummh Paper!
• Design contexts include: photo-realistic concept and presentation models, design and ergonomic prototypes, durable living hinges, low-cost castings and moulds for vacuum forming .
• Design contexts include: appearance models,
• MCOR technologies article

Advantages	Disadvantages
Low cost Readably available material Paper has a wood like structure so can be worked or finished by similar techniques Large parts can easily and cheaply be made Can be a low capital cost for machine Use recycled paper	Lower dimensional accuracy (low fidelity) than LOM or SLS when using more traditional techniques (i.e. not MCOR) In UCD – may not be quite like the intended outcome. 3D printing for paper prototyping can has a high initial capital cost for the machine

Laminated object manufacture (LOM) (see rapid prototyping topic 3)

• A rapid prototyping systems that creates a 3D product by manufacture (LOM) converting it into slices, cutting the slices out and joining/gluing the slices together
• Materials used:  paper, plastic, or metal
• Design contexts include: models, prototypes, vacuum forming moulds, pattern (for casting), or one-off products

Advantages	Disadvantages
no need for support structures only the shell is produced capability for  high manufacturing speeds	can produce whole products that are hollow poor surface finish

Stereolithography (see rapid prototyping topic 3)

• Materials used: photopolymer (photo sensitive polymer)
• Design contexts include: functional parts, pattern (for casting), pattern for various moulding techniques,
• Stereolithography aide surgeons for ear implants case study

Advantages	Disadvantages
Fast – functional parts can be made in a day Can be machined	Cost of the material a photosensitive resin Initial capital cost of machine

Cutting

• Is where a material is reduced into he desired shape through sitting away material.
• Saws (power and hand held)
• Scissors (power and hand held)
• Thicknessser/planer, router,  (equipment/power), spokeshave, sureform, plane (hand held), oxy-acetylene and plasma cutter (hand held)
• CNC (automated) – laser, plasma (can be hand held as well) or water jet cutting
• Materials applicable for: wood, plastics, metals, ceramics/stone and textiles.
• Design contexts include: Wall clocks, artwork, puzzles, toys, living hinges, flat pack furniture,  This website has some more examples.
• Advantages/Disadvantages of CNC cutting

Advantages	Disadvantages
equipment and CNC have a high accuracy equipment and CNC produce a high quality finish produce very fine details minimal distortion	equipment and CNC initial costs are high special training/skills are required

	Hand Saws

Machining

• Is the removal of material by a tool that moves across the material by use a machine or large equipment.
• Drill press, mill machine, lathes or shaper
• Can be CNC (automated) or mechanised
• Materials applicable for: wood, metal, plastics, ceramics,
• Design contexts include: components or parts for engines, for assemblies,

	Mill Machine

Advantages	Disadvantages
High accuracy can be achieved equipment and CNC produce a high quality finish produce very fine details CNC/CAM allows for 24/7 production	equipment and CNC initial costs are high special training/skills are required less workers requires in a CNC/CAM work environment

Turning

• The material is held between two centres and the tool moves longitudinally across it removing material.
• Wood or metal lathes
• Can be CNC (automated) or mechanised
• Materials applicable for: Wood, metal and rigid machinable plastics (nylon, delrin)
• Design contexts include: baseball bats, candle sticks, pens, cylindrical/Conical parts or components for assemblies for industries such as automative or aerospace.
• Advantages/Disadvantages see machining

Milling

• The material is held firm in a vice on a movable bed and a rotating cutting tool sweeps along the paths on the surface of the material. The bed moves the material around while the cutting moves only through the z-axis.
• Materials applicable for: wood, metal, rigid machinable plastics.
• Design contexts include: molds for injection moulding, ventilators, pens, paintball guns, rims for tyres, guitars, parts for wooden clocks, etc
• Advantages/Disadvantages see machining

Drilling

• Is boring a hole into a piece of material. The Material is held firm and does not move and a rotating drill bit moves through the z-axis removing material.
• Materials applicable for: wood, metal, ceramics, plastics.
• Design contexts include: wooden pens,  a hole in the stop of a candle stick, or anything that requires a hole.
• Advantages/Disadvantages see machining,

Abrading

• Wearing away material using abrasive material.
• Sand or abrasive paper, scapers (hand held tools)
• Grinders (bench and hand held)
• Disk, belt and spindle sanders (equipment and power tools)
• Materials applicable for: wood, metal, ceramics/glass, plastics
• Design contexts include: used to make things smooth, round edges usually a process used as part of the overall product of a product.

Advantages	Disadvantages
provides a good finish takes sharp edges away – safety Cheap shaping technique – relatively low capital cost	can be noisy so health hazard can be dusty so health hazard

Shaping techniques:

Are manufacturing methods for modifying the shape of a material.

Moulding

• Heat a material until it is a liquid or pliable state.
• Then placing into a mould.
• Materials used: usually  plastic/polymer but can be glass or metal.

Common types moulding …

• Injection moulding
  • Producing products or parts by injecting plastic into a mould.
  • Can considered a clean technology as there is little waste.
  • See below video on the Paton Chair
  • Materials used include thermoplastics
    • Design contexts include: plastic garbage bins or tubs, plastic combs, or anything that is usually plastic and mass produced.

Advantages	Disadvantages
fast production material and colour flexibility low waste design flexibility	high initial capital costs part and size design restrictions

• Blow moulding
  • Is the process of inflating a hot, hollow, thermoplastic that is inside a closed mould. A blast of hot air is sent in which expands the plastic so it conforms which the mould cavity.
  • Can considered a clean technology as there is little waste.
  • Materials used include thermoplastics and glass
  • Design contexts include: bottles,

• Rotational moulding
  • Heated hollow mould is rotated during the heating up of the plastic and cooling.
  • Materials used include thermoplastics
  • Design contexts include: water tanks, buoys, pontoons, toys

• Compression moulding
  • Where the material is heated so it is pliable. It is placed in an open mould that closes and compresses the material to the shape of the mould cavity.
  • Can considered a clean technology as there is little waste.
  • Materials used include thermoset plastics and ceramics, Special thermoplastics
  • Design contexts include: power sockets,

https://www.youtube.com/watch?v=-FxiWMnY4aQ

Thermoforming

• Where a plastic sheet is heated  until it is in a  pliable state. Then placing into a mould to form a shape. Vacuum forming is a common method used.
• Materials used:  thermoplastic
• Design contexts include: disposable cups, egg cartons,  trays, blisters, clamshells, . e door and dash panels, refrigerator liners, etc

Advantages	Disadvantages
high speed production material optimization Cost effective material flexibility low cot of tooling	shape and size restrictions matching of the edges are required

Laminating

• sheets of thin veneer (about 1 mm thick) are layered with a glue (polymer) in-between.
• Materials used: glass, timber, paper and plastic
• Design contexts include: chairs, plywood

Advantages	Disadvantages
range of veneers available strength to weight ratio Cost effective flexible in design	time consuming moulds will have to be made bends need special consideration

Casting

• Pouring a molten material (metal) into a mould. Often the mould is broken. The shape is called a casting.
• Materials used: metals.
• Design contexts include: sculpture, parts for cars (engines etc), marine propellors

Advantages	Disadvantages
complex shapes can me made cost-effective flexible in size (really big castings can be made)	finishing is required labour intensive for sand casting

Knitting (see textiles)

• Yarn is used to produce fabric or textiles. Loops are formed and stitched together.
• Materials used: synthetic and natural fibres
• Design contexts include:  fabric, scarves

Weaving  (see textiles)

• Weaving is an ancient textile art and craft that involves placing two sets of threads or yarn called the warp and weft of the loom and turning them into cloth. In general, weaving involves the interlacing of two sets of threads at right angles to each other: the warp and the weft.
• Materials used: synthetic and natural fibres
• Design contexts include: fabric, tapestries, scarves

Joining techniques:

Permanent

• Adhering (or Gluing) – the use of adhesives (glues). One part receives a layer of an adhesive substance, and the second part will be placed next to the object with the sides touching. Once the adhesive dries, the products have been formed into one object, with the adhesive between the two holding them together.
  • Design contexts include:

• Fusing (this includes welding and brazing)
  • Fusing is a manufacturing technique used to join similar materials together by melting them at high temperatures and usually adding a small amount of a similar material.
  • Design contexts include: used in combination in producing artefacts. Artwork maybe produced by welding decorative polices together. Construction of steel frames.

• Fasteners (Permanent )
  • include  nails, rivets,
  • Design contexts include: used in combination in producing artefacts. Often used for two dissimilar materials.

Advantages	Disadvantages
cost effective – low cost permanent easy to carry out	Cannot be taken apart if something needs replacing welding or brazing requires skills welding or brazing requires specialised equipment welding or brazing has safety issues

Temporary

• Fasteners (Temporary)
  • The use of fasteners stands for using certain connecting devices to join two or more dissimilar materials together. They can be undone to separate the materials if needed.
  • Types of temporary include – nut & bolts, screws, keys, studs, pins, rings, rivets and nails, velcro and knock-down fittings.
  • Design contexts include: to join two or more dissimilar materials together. Used in flat pack (think Ikea) furniture

• Adhering
  • Thermoplastic glue such as that used in hot glue guns
  • Design contexts include: holding materials or electrical components in place  temporarily

	Velcro

Appropriate manufacturing techniques

• When selecting manufacturing techniques it should be based on the following criteria
  • Material characteristics such as form, melting/ softening point.
  • Cost
  • Scale of production
  • Desired properties

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International Mindedness

More expensive modern processes tend to take place in technologically advanced regions/ countries.