Additive Manufacturing (AM) can become Addictive
In its simplest form, three-dimensional printing is the layering of materials that replicates precisely whatever input (usually from a CAD drawing) is received and requested by the ‘printer unit’. As if by magic, a working component can be produced from powder, liquid, metal, plastic, concrete and, in future, even human tissue, in a manner that would age Mary Shelley’s ‘Frankenstein’ to its Dickensian roots.
So fast changing is the technology that, no sooner has a comment, or critique, been committed to paper (or screen), another development makes it history. Of course, this formative period can make it very awkward in investment terms, not so much for the corporations funding the technology but for the manufacturing and service operations becoming early adopters of it.
The origins of Additive Manufacturing lay with the brains at Massachusetts Institute of Technology (MIT), which has a proud record of technological innovation. While its potential is probably beyond the current thought processes of many of us, not least in the medical area of reproducing human organs, the ethical and moral implications for which are simply immense, its applications within the manufacturing sector, for rapid prototyping, is already well advanced.
On a recent visit to Lotus Engineering, an arm of the Norfolk-based sportscar company, I watched in total amazement, as a brand new air inlet was developed for a future model that was already in the design studio. The speed with which the transfer took place from the design chief’s pen, to computer, to a photopolymer resin printer was mind-boggling. Naturally, as with numerous advances in technology in many fields, Lotus’s expertise arose from its commitment to Formula One racing. While SLA (Stereo Lithography Apparatus) has always been an expensive process, the costs are already dropping dramatically in terms of hardware, source materials and power requirements, to such an extent that ‘domestic 3D printers’, available for around an anticipated £500, will soon be available; sooner than you might believe were possible.
The prospect of (almost) instant gratification on the customising front, let alone for industrial tooling, or even small run production components, is mind-blowing. While it might seem like a dystopian adventure to some observers, the prospect of machines building machines, or even, for some existing companies, producing liveable structures, is actually more utopian…but available imminently.
Thermoplastic printing (FDM – Fused Deposition Modelling), MJM (Multi-Jet Modelling), full-colour 3D printing (3DP) and SLS (Selective Laser Sintering) are techniques that already well-advanced and have been so for almost a decade now. However, along with greater affordability weighs in a raft of benefits that the manufacturing scene will find compelling, not the least of which are a massive reduction in waste, slashing inventories and reducing down times, while awaiting component deliveries, factors that can make the difference between a business being profitable, or being forced to face the wall.
Traditional ‘subtractive’ manufacturing processes can often demand the removal of up to 95% of the raw materials to arrive at a finished part, while additive machines need only the materials that constitute its manufacturing. Yet, it is designers, who feel the greatest reward, as they are freed from the constraints of traditional manufacturing processes. The more complex the end component, the more beneficial is AM.
When you compare traditional with additive manufacturing, the end results can start to look as though they are miles apart. Engineering a component from a billet of material that might have to undergo finite stress analysis, heat treatment and topology optimisation, all prior to machining taking place, a load-bearing component, however beautiful it might look, will have demanded many processes in order to be produced. On the other hand, the AM structure is exceptionally complex but the layered construction replicates the specification, without redundant weight penalties, yet it is capable of meeting and exceeding all design parameters.
However, while blanket applications might meet the corporate demands of innumerable manufacturers, which are always attempting to balance the costs versus profits elements of running their businesses, for service companies like ISQA, a need for even more intense scrutiny and assurance will remain on demand. At the end of the day, the machine, however advanced, is only as capable as its operator, or information injector. As yet, the dark arts involved in orientating the layers, because there are no computerised, or even automated, shortcuts available (as yet), still require engineers to make manufacturing decisions.
There are issues with the equipment available currently. They are sensitive and require very careful optimisation. Maintaining an appropriate operating temperature is essential, as the machine properties, working with different materials, can alter on different days. In addition, design software is still trying to keep apace of the hardware developments, which is a most unusual technological situation, while production speeds will have to increase to meet significant volume demands. Multiple material applications are also under development and carbon-nanotube technology is being fast-tracked.
Yet, whether manufacturing porous replacement human hip joints, loaded flexible components for the aircraft industry, small fittings for refineries, or trim elements for a luxury motorcar, the application of the most magnificent supercomputer in the world – the human brain and the senses that feed it – still has a valuable place and role to fulfil. QA is still core to successful, problem and recall-free manufacturing. ISQA realises that AM does not signify the demise of conventional moulding, or machining, even though it will start to appear increasingly on the shop-floor.
‘Make Quality Count!’