In the world of engineering, product design and prototyping, everyone has heard of 3D printing. Sadly the majority of professionals working in the industry still struggle to identify the most promising use-cases for the technology, and often time and money is wasted chasing 3D printing for its own sake, or as an exciting manufacturing process, rather than because it is a fundamentally good fit for the project at hand.
This lack of understanding is one of the issues that has led to many of the negative experiences that some people have had with additive manufacturing (AM), and as with anything, a bad first experience can stick for life. This leaves these unfortunate designers and engineers reluctant to engage with a technology that is spectacularly powerful when used correctly – which is a tragedy.
That’s why I’ve categorised every great application of 3D printing into one of the three (and a half!) cases below. It’s a short and simple list, but if the way you’re considering using AM doesn’t fall neatly into one of these, then the chances are you’ll end up disappointed with the result.
This is the most frequent use-case, leading to the common synonym of ‘rapid prototyping’ which is used to refer to 3D printing by many people. Whether your design will eventually be injection moulded, cast, CNC-machined or fabricated, printing one or more prototypes to confirm that everything works the way you expect it to is always a smart move.
The mantra of “prototype early and prototype often” is worth repeating; It is exponentially cheaper to fix problems when they are identified early in the design cycle than later. Holding a product in your hand and physically interacting with it is the single most powerful way to spot issues with fit, form and function immediately.
Whether you are a product designer, mechanical engineer or technician, a thorough understanding of the principles of design for manufacture (DFM) will be invaluable throughout your career. For some applications though, conventional manufacturing methods can restrict your options so much that there is no path forward, and at times like that, additive manufacturing can be the ace up your sleeve that allows you to solve the problem.
Complex internal channels that optimise airflow; tiny features in seemingly inaccessible locations; beautiful lattice structures designed to optimise heat exchange… the most innovative and advanced designs demand nothing less than the most innovative and advanced manufacturing technologies to create them.
Be careful though! Design for additive manufacturing (DfAM) is a complex discipline in and of itself. “Don’t worry, we’ll 3D print it” shouldn’t be used as a ‘Get of Out Jail Free Card’ which permits you to submit wildly impractical designs for no other reason than you didn’t feel like reworking your design to make it machinable. You have been warned!
Injection moulding, CNC-machining and many other manufacturing processes are inherently influenced by economies of scale. Generally, this is not the case for 3D printing. This means that if you’re producing 10,000 of the same plastic electronics casing, then I cannot emphasise enough that 3D printing is not the way to go! The cost per part when additively manufacturing designs stays relatively static as production quantities increase.
If on the other hand, you only need five or ten copies of your design, for a novel experimental test rig perhaps, or very short production run of certain components, then printing will certainly be worth considering. This applies whether or not the design was originally intended to be 3D printed. Think discontinued parts from classic cars, or one-off replacements for a broken machine component on a factory floor.
The exact point at which short-run production changes from being economically and practically viable using 3D printing, to being better suited for other processes, varies. Often it lies somewhere between 20 and 100. More than that, and you should probably stick to more conventional methods.
I’ve classed this one as half an application (because its really a sub-category of number three, with some elements of two thrown in) and it is the possibility of mass-customisation. This is the production of a basic design that is adapted slightly for every part, so as to meet the requirements of the end-user perfectly every time.
A very simple example of this would be integrating a different company logo into every part manufactured, and a more complex one might be custom made artificial knee joints, that are perfectly adapted to fit an individual patient’s anatomy. This second application is a major focal point of medical engineering research, and overlaps heavily with trends around ‘personalised medicine’ that will dominate the coming decades in health innovation.
So, there you have it! Hopefully this will help clarify the value of 3D printing, and assist you when identifying whether an application would really benefit from an additive approach. Was this useful? Do you have a great use-case that defies categorisation using this method? Let me know what you think!
