Tools, equipment and processes
Forming
Most materials need specialist tools and equipment to shape and form them. casing A removable outer layer of a product. and housingAn exterior case or enclosure. for electronic and mechanical products is shaped and formed to fit and protect products, making them more practical and aesthetically pleasing.
- vacuum forming Warmed sheet plastic is sucked against a mould to give it shape. - plastic casings can be vacuum formed over a form giving a thin casing that an electronic circuit can be hidden in
- injection mouldingMolten material forced into a mould. - molten plastic is injected into a mould giving an accurate form that can vary in thickness, ensures pieces fit together accurately, and can encase the electrical or mechanical parts, such as in children’s toys
- castingA method of producing a form by pouring molten liquid into a mould. - mechanical products, such as engine parts, can be made from metal and are formed by pouring molten metal into a mould to make a solid, strong and accurate shape
- bendingA bending force is applied at an angle causing a material to be in compression and tension at the same time. - simple shapes can be formed by bending sheet metal or heating and bending plastic to provide a casing for products such as fuse boxes
Wastage
Wastage is the process of cutting away material with tools and equipment. Good design can minimise the amount of wastage produced. For electronic and mechanical systems, there are several wastage processes available.
- laser cutterA machine that uses a laser beam to vaporise material and cut out shapes very accurately. - can use computer aided design (CAD)The process of creating a 2D or 3D design using computer software. programs to draw and then cut any shape out of wood, plastic or circuit board and can also cut out intricate shapes, such as plastic gears
- Guillotine - printed circuit boards (PCBs) should be cut into shape before any components are added, and the most accurate way to do this is with a guillotine, which uses a sharp blade to chop through the sheet
- Drilling - holes can be drilled through a PCB to provide an accurate place to add components either by hand or using a computer numerical controlled (CNC) routerA method by a computer to execute a pre-programmed sequence. Machines move via numerical values along X, Y and Z axes.
- Computer numerical controlled (CNC) router - for the cutting, engraving and drilling of PCBs, the cutting blade works by spinning and moving along a pre-programmed route quickly and accurately
Addition
Addition is the process of adding on material.
- soldering A method of joining, usually electrical components, by heating a filler metal called solder. When the solder cools, it fused the components together. - can be done by hand or machine, where solder is heated until liquid and then added to the components and PCB where it cools and sets, allowing electricity to flow from one point to another
- weldingA method of joining metal by the addition of molten material. - by melting the work material as well as the filler or welding rod, it creates a strong bond that can join metals together in mechanical systems
- arc welding is used for manufacturing products with mild steelSteel with a low carbon content (around 0.25 per cent)., eg trailers
- mig welding is used for light steel, eg in car bodywork
- spot welding is used to attach panels of metal together
- gas welding is used for joining pipes
- 3D printing A method of adding material in layers to build a solid form. - can be used to build up or cover areas that need protecting, producing very little wastage, but it is time-consuming and expensive
