In 2017 a consortium of companies, universities and research institutes came together to explore the potential for hybrid manufacturing in medium and large-scale construction. The result was the LASIMM (Large Additive Subtractive Integrated Modular Machine) Project, which led to the development of a scalable manufacturing system combining 3D printing and subtractive techniques to produce large metal parts.
The LASIMM employs a dual-robotic system, one for additive manufacturing of aluminium and steel, and the second for machining to finish and remove any excess material. The three-year project recently concluded with a series of demonstrator parts for three industrial end-users including British architectural design and engineering firm Foster + Partners. Here, Johnny Van Der Zwaag, project manager in the Collaborative Research and Innovation team at Autodesk, which developed the software to drive the LASIMM, gives TCT an update.
Q: The LASIMM project went live a little over three years ago and has now concluded - what were the key findings from the research?
A: When the LASIMM project kicked off, we worked with the project partners to build the large cell the machine would reside in. We then assembled the LASIMM, built the software that would drive it, and began testing it to build parts using aluminium and steel.
Parts were manufactured – both additive and subtractive methods – for three end-users in Architecture (Fosters + Partners), Aerospace (BAE Systems), and energy (Vestas).
Typically, the main objective for materials research is to improve performance through areas such as time savings, using less material and therefore reducing waste. We found that the effectiveness of the machine with dual-robots and integrated machining capabilities outweighed traditional manufacturing methods, because of the increased flexibility and robustness of the machine, as well as reduction of work floor space and inventory required. Not to mention, this could enable more localised manufacturing environments and reduce the length of the supply chain.
The technology also has the potential to transform the supply chain for architectural projects. Though the machine used in LASIMM was large, its functionality could be replicated using smaller, more portable components and configurations.
Johnny van der Zwaag
Q: Can you talk about the types of demonstrator parts you’ve been working on and why these parts were a good fit?
A: The parts were designed by leading industrial end-users Foster + Partners, BAE Systems and Vestas to enable the machine to reach its full capabilities.
The machine first started working on a steel cantilever beam designed by Foster + Partners. The full design of the beam was five meters long, 0.5 m wide and 120 mm deep, tapering to the end, where it’s 50 mm deep. The beam was designed for a load of a 500 kg point load at the tip.
Different-size beams were tested with the machine (five meters, two meters, and options in between), which showed potential uses for different scales. The generative workflow adapted its designs to the different shapes and dimensions.
The additive construction process for the cantilevered beam began with a steel plate, with components welded on layer by layer. Below is an image demonstrating what was built in full; which was the two-metre beam, with final measurements of 2 x 0.4 x 0.05 metres.
BAE Systems is active in developing additive manufacturing and complementary processes to support current and future air platforms. It provided expertise in the definition of part and process requirements from an industrial perspective. During the LASIMM project, a demonstrator part was built in aluminium for BAE. This part was a fuselage frame, which is a primary airframe structural component that is dynamically loaded during the aircraft operation and is safety critical. Today it is typically machined from solid billets, and so Directed Energy Deposition (DED) is used to reduce the waste and reduce lead times. The size of this part is about 1 metre by 0.5m and 100mm high (50mm each side).
For Vestas we looked at a component from the wind turbine, at hybrid manufacturing the main shaft: adding features to a generic shaft. The part was less developed than the other two end users for a couple of reasons. Firstly, the part was designed originally for casting rather than additive, dual-sided building on a planar plate. There was also timing constraints in the project, outlined in the next question. As a result, the focus for Vestas was on redesigning the casting component to benefit additive manufacturing, and less so on making the demonstrator part itself. The energy end user’s case was interesting because it looked at a different aspect of hybrid: adding features to an existing shaft and exploring how it could be done, revealing another field for additive to be used in.
Q: Did you come across any challenges or limitations along the way?
A: There were various challenges to tackle in order to make LASIMM a successful research project, managing the complexities of such a machine and the timeframe we had.
From a software point of view, we had to ensure the robot arms were programmed to work together in parallel, yet still independent from one another. The machine would build on both sides of the part, so it would be flipped, and then each robot would need to know where the right place was to continue welding. In addition, both robots work on different areas of the same part and needed to do so without interfering with each other (collisions) or interfering with each other’s process. This was successfully achieved but ensuring the two robot arms worked effectively on one part without interrupting one another was an important part of driving the machine. Zoning (dividing the work across multiple robots) was done in such a way that both robots were manufacturing as efficient as possible by minimising waiting times.
The project timeline was slightly pushed back due to some delays in assembling the cell, as well as complications with the size of the beam with the material used.
The robots were provided by the robot integrator partner, Global Robots, based in the UK. We needed to start assembling the robots at its facility first, to ensure we had parallel access to the additive and subtractive hardware. Once the robots were shipped, they needed to be fully assembled and fine-tuned to the necessary requirements before they could start building. This is an intricate process and needed to be done sequentially. The timing to get this right was longer than anticipated, but it was a necessary part of the assembly and testing, to understand different hybrid manufacturing methods as part of LASIMM.
Another challenge we faced was complications with the materials used for the cantilever beam.
Buckling occurs when heat from the welding process distorts metal into a paraboloid saddle shape. Balancing the heat distribution on the plate required printing on one side and then rotating to print a mirror structure on the reverse side, because the plate was constantly being flipped and then printing another layer. The symmetry of the large parts was also essential, which was one of the constraints: the orientation of the parts relative to the original plate. As a result, two out of three of the demonstrator-builds for each of the end-users were completed, and only a proportion of the Vestas part.
Q: When we last spoke with Autodesk, we heard how the project had “brought hybrid manufacturing to a truly global and industrial scale” - can you elaborate on that now the project has concluded?
A: We can see huge potential for the manufacturing industry to take learnings from this hybrid machine. LASIMM took the technology available for manufacturing to a higher level. It changes what’s possible in the way we make parts, but also the way manufacturing can collaborate with other industries.
The process of more than one robot working together is not new, when you consider its already used in the automotive industry. However, we have taken that approach and applied it to software for manufacturing. Creating this safe system between two robots, where they understand and are talking to each other is a further step forward to hybrid manufacturing being used at an industrial scale. It means we can manufacture parts faster and scale up to make bigger parts. Not to mention, the time savings, using less material, reduced inventory and work floor space. The potential is to localise the manufacturing environment, which would also reduce the carbon footprint that comes with shipping parts worldwide. LASIMM’s functionality could be replicated using smaller, more portable components and configurations.
Q: You’ve been working with Foster + Partners who used the technology to produce a structural beam - can you talk about the benefits this afforded them and if they’re keen to apply the technology to more parts/projects going forward?
A: For architecture firm Foster + Partners, the studio was able to research and test the science behind the materials uses in buildings, to understand the requirements for the spatial or performance characteristics of the design. Being able to 3D print and have great control over structural volumes, means it could control the geometry and integrate lighting, ducts, airflow, heat transmission, and acoustics directly into the structure of the part.
A goal for its future projects is to devise ways to print more freeform shapes and build onto a smaller plate. The beam won’t be used in an actual construction project but will likely be displayed at F+P’s London offices as a research artefact.
The designers at F+P plan to explore how LASIMM could work with other disciplines, fabricating other materials and integrating what it can fabricate with timber, carbon fibers, etc. Additive construction is being used for different purposes in the industry, but F+P are interested in merging it into new techniques to use material more effectively. When materials are used that are off-the-shelf or cast concrete into forms, there are constraints and limits as to how it can be used. The goal is that it will eventually become more cost-effective to use additive processes in the industry.
Q: The technology is capable of producing huge metal parts - where do you see this technology having the biggest impact?
A: The technology has the potential to transform the supply chain for architectural projects, as we have seen with Foster + Partners’ work to date.
We have already seen this technology having an impact on the maritime industry, for example the RAMLAB project enables on-demand, on site, spare part manufacturing – removing the need to storage of spare parts in warehouses and reducing wait time for parts.
Aerospace is another industry looking at the potential of large-scale additive, which can enable lead-time reduction to deal with supply issues around titanium forgings (typically 12+ month lead times). However, there is no room for defects in materials in this industry, and therefore extensive research and safety testing is critical.
Industries that have more scope to explore new materials include those that build launch vehicles for space research and satellites. Relativity is a company looking at merging more parts into one, where smaller and lighter parts are highly favourable.
Q: In terms of AM for construction, it seems as though every day we see a new “world’s first 3D printed building” of some sort - are we likely to see this technology become a mainstream part of the construction industry?
A: We see AM as a complementary technology for construction. Indeed, for some components, prefab is the best solution and for others it is on-site, customisation that uses local raw materials to 3D print parts, like Royal BAM Group is doing with concrete.
Over the past few years, concrete printing has emerged as a popular manufacturing method for bridges, homes and other structures. It’s the perfect fit for additive technology, offering speed, accuracy and it can be done on-site with gantry-style extruder 3D printers. It is also useful for locations where prefabricated components cannot be transported by trucks, but the raw material can be transported – or local material used – and built on site.
Customers including Foster + Partners and AI Space Factory have been exploring AM methods for building on Mars, which can also inform more sustainable construction methods we can use on Earth.
As the global population increases and cities become even more crowded than they are today, we need to build things faster. The convergence of manufacturing and construction is redefining the future of making, changing the way the industry builds.
Q: Now the research phase is complete, what are the next steps or ambitions for the project?
A: The European Commission will build on the learnings and takeaways of this project to invest in further projects that bring us closer to commercial application of a machine like LASIMM.
Often, such projects run in isolation, so the commission launching opportunities for new projects means more industries can work together, share knowledge, and learn from one another to test new innovations for manufacturing.
For Autodesk, building large-scale additive allows us to feed this experience into the development of our software and capabilities for customers with PowerMill Additive and Fusion 360.
