Whilst the development of materials and techniques suitable for large scale manufacturing has sometimes been slow to progress, the role for 3D printing in producing prototypes, or patterns for moulding them, has never been in doubt.
Something like 80% of commercial printers are used for prototyping, and according to a recent forecast, the global market for rapid prototyping materials will reach over $900million within the next 3-4 years.
So when McLaren Racing announce a four-year partnership with a 3D printing company, it drums home the fact that the technology has come of age. In fact, motorsport is increasingly reliant on rapid 3D prototyping.
Speed is of the essence in motorsport, and not just on the track. Parts are often one-off and replacements, whether copies or new designs are needed quickly – too quickly to send blueprints away to engineering shops to set up new moulds for castings and so forth. The whole car is essentially one big assemblage of prototypes, constantly being tweaked to squeeze a little extra performance or to solve a weakness between every race.
Using a 3D printing service has enabled the turnaround on such parts to be reduced from something approaching a week to as quickly as overnight.
One of the technological challenges in using 3D parts for this kind of purpose has been their temperature stability. Some materials melt at low temperatures or expand way beyond demanding automotive tolerances. However, materials available now can withstand temperatures of at least 120°C – easily enough for testing purposes, if not for actual end components.
As well as metallic materials, developments in carbon fibre are believed to be enabling this new generation of high-spec printed products. In fact, a 3D printing bureau will typically see this rapid prototyping as an opportunity to demonstrate that its production equipment is up to the job of full commercial product manufacturing – not just for the prototype.
More sophisticated 3D printers enable different materials to be mixed on the fly, and can thereby produce an item with different properties at different locations within it. In this, 3D printing is exceeding the capabilities of traditional manufacturing technologies, where parts made of different materials almost always have to be made separately and somehow glued or riveted together, often introducing weak points and extra construction costs and weight.
3D construction methods often allow a thorough internal redesign, not just of the component shape as such, but in the very structure of the material from which it’s built. For example, solid castings can be replaced with honeycomb structures of equal strength but much less weight, which is ideal for aerospace applications.
The most common technologies used by the 3D printing bureau to produce a prototype are variations of Stereolithography (SLA) – such as DLP (digital light processing), Fused deposition modelling (FDM), Selective Laser Melting (SLM), or the newer Selective laser sintering (SLS, and similar DMLS). All treat the product as a succession of 2D layers constructed consecutively, which can introduce fracture plains into the product or a discontinuous “digital” surface. Newer techniques (Continuous Liquid Interface Production, for example) create more continuous parts, with perfect finishes, and extend even further the range of unique materials that can be made with 3D.