Additive manufacturing
- Additive manufacturing builds parts layer by layer, instead of removing material. It is often called 3D printing.
- Fused deposition modelling (FDM) melts a plastic filament (such as PLA or ABS) and deposits it layer by layer.
- Stereolithography (SLA) uses a UV laser to set liquid resin, giving fine detail.
- Selective laser sintering (SLS) uses a laser to fuse powdered material, including metals and nylon.
- Advantages: complex shapes that can't be machined or moulded, very little waste, no tooling needed, easy customisation and rapid prototyping.
- Disadvantages: slow for large numbers, limited materials and sizes, visible layer lines, and parts may be weaker between layers.
CAD and CAM
- CAD (computer-aided design) is used to draw and model parts in 3D. Designs can be changed quickly, shared electronically and tested virtually before anything is made.
- CAM (computer-aided manufacture) uses the CAD data to control machines such as CNC mills, lathes, laser cutters and 3D printers.
- Together, CAD and CAM reduce errors, speed up development and make parts consistent. But software and machines are expensive and staff need training.
Rapid prototyping
- Prototypes let engineers test form, fit and function early, finding problems before expensive tooling is made.
Key terms
- Additive manufacturing
- Building parts layer by layer.
- FDM
- Fused deposition modelling, which deposits melted filament in layers.
- SLA
- Stereolithography, which uses a UV laser to set liquid resin.
- SLS
- Selective laser sintering, which fuses powder with a laser.
- CAD
- Computer-aided design.
- CAM
- Computer-aided manufacture.
- Rapid prototyping
- Quickly making test models of a design.