Rapid advancements in 3D printing have enabled new types of additive and hybrid manufacturing on a larger scale, explains Jan Larsson – senior marketing director EMEA, product engineering software at Siemens PLM Software.
3D printing is on the verge of mainstream adoption as businesses begin to recognise and embrace the cost and product manufacturing benefits of the technology.
This is predominately being driven by consumer and small-scale businesses, but it also has a significant impact on industrial manufacturing.
The challenge
While 3D printing offers the potential to significantly speed and streamline selected processes, it also brings challenges.
The first is the evolving nature of the technology, the available application knowledge and economic justification challenges.
Calculating the trade-offs between tooling costs, for example, and incorporating a 3D printing process for near-net shape development is difficult in a changing landscape with relatively few guideposts.
Manufacturers who want to move this technology out of the prototype shop and into production today are classic early adopters. There’s a consequent difficulty in justifying investment and making implementation decisions.
This combination means that a successful implementation in a single manufacturing application can take months, if not longer to complete.
Furthermore, additive manufacturing requires converting CAD geometries to STL files, involving inherent inaccuracies several orders of magnitude in difference to traditional subtractive/machining manufacturing.
Plus, additive manufacturing doesn’t currently allow dynamic monitoring of the process, something that is more or less standard with conventional machining.
Not only does it require new machines, but the shift from traditional subtractive manufacturing techniques to an additive – and ultimately hybrid – approach requires a new mindset with tools and processes to match.
Demand and bespoke manufacturing
Two of the primary benefits of 3D printing are the ability to create one-off custom products and non-standard, complex designs as a single unit.
This has a wide range of benefits that can offer savings on time, resources and costs.
A simple example comes when creating struts. Rather than a solid bar that is heavy and needs to be shaped, a 3D printed version can be hollow with a complex internal support structure and be printed in the shape required.
This is ultimately faster and the result is stronger, lighter and uses less material.
Also, a design that would require multiple parts being created and then joined later, can be printed as a single object.
When using conventional detractive manufacturing techniques, even relatively straightforward assemblies can require lots of separately produced parts, adding expense and limiting design options.
Using additive manufacturing, the object can be produced as one part in a single step, while being made lighter and more durable at the same time.
The freeform customisation that additive manufacturing offers not only enables rapid prototyping, but also means basic designs can be modified to individual requirements.
For the medical profession this means parts such as artificial knee and hip replacements can be created to the exact specifications of the patient.
Not only can 3D printers enable the creation of new designs but also new materials.
This isn’t just moving from plastics to metals and alloys, but whole new material categories that would never be generally considered in traditional manufacturing.
These include malleable and biological materials for use in the medical and food industry. Even in more traditional metals, there is an opportunity to introduce density gradients or multi-material configurations that aren’t possible with traditional metal forgings and castings.
A new design ecosystem
All of this points to an exciting and innovative path for the future of manufacturing, but realising that vision requires a whole new design and manufacturing ecosystem.
At the design level, it requires new CAD tools for the design of lightweight structures and complex surface patterns, as well as additive manufacturing design rules and multi-material support.
Additive manufacturing enables more complex structures – and especially unseen internal structures – in the finished parts.
Such structures have an increased requirement for up-front structural analysis in order to gauge the ability to withstand required stresses and test performance in different scenarios.
Increased structural complexity also introduces additional quality control challenges, as traditional CMM inspection may not be able to provide a complete picture
Similarly, there needs to be changes to CAE analysis systems to offer topology optimisation tools, deformation calculations and laser power regulation.
On the shop floor, new CAM systems will have to feature multi-axis additive solutions, as well as hybrid manufacturing controls and processes.
In this environment, the wider manufacturing ecosystem also needs rethinking. The ability to generate parts to order make it possible to take a zero inventory approach, which in turn leads to restructured supply chains.
Ultimately, this requires new worker skill sets and a more collaborative approach to the entire design and manufacturing lifecycle.
A hybrid approach
Despite the numerous benefits that additive manufacturing brings, it is not without its flaws – primarily in terms of accuracy and resolution (surface texture).
The solution here is to adopt a hybrid approach that incorporates additive approaches with machining in a single system.
This involves creating the object using an additive manufacturing process and then completing the finer detail by essentially shaving off the rough edges.
This approach also solves the problem of tolerances and accuracy as measurement and smoothing can be done on the final product.
The ability to add and remove material in small increments also enables designs to be tweaked and adjusted on the fly, rather than recreating it from scratch. As such, the analysis and testing phases can be much quicker and more accurate.
This approach also improves and simplifies maintenance and repairs. Worn or broken products can simply have some material added and then refined to become good as new.
For simple, high volume products, traditional manufacturing will remain in place for the foreseeable future.
But additive and hybrid manufacturing offers possibilities in whole new industries and a new approach to the design and creation of certain items.
There is clearly a business case for using additive manufacturing for certain production parts, but developing the required process knowledge can involve a tremendous investment in time and resources.
Developing this sector beyond just niche and small scale production requires the support of the whole industry to develop the tools required to support manufacturers that are adding additive and hybrid machines to their manufacturing process.
