A number of new and reoccurring trends have emerged across the additive manufacturing and 3D printing industry throughout the course of 2016, not least in the area of robotics. For the uninitiated, such as myself, the term robotics might conjure images of cute little (or large) humanoid robots that are programmed to imitate human behaviours.
In fact, the term robotics is much more inclusive and encompasses a vast array of industrial scale machinery and equipment that supports automation. Multi-axis robotic arms are one category within the fast growing robotics sector, and this year there has been a notable cross-over into the additive manufacturing sector in a couple of different ways — directly as a method of controlling a print head that deposits materials and indirectly as a way of facilitating an automated end-to-end additive manufacturing solution.
Both robotics and 3D printing are generally considered to fit in the realm of ‘emerging technologies’ independently courtesy of their (relatively) short histories, fast evolution and expanding user base. However, the intersection between the two, while currently small, now appears logical and will inevitably grow in terms of size and application. It is a comfortable fit, an observation that crystallised for me at the recent Formnext exhibition where a number of incumbent additive manufacturing system vendors were demonstrating new technology concepts and/or platforms introduced in 2016 that incorporate robotic arms in one form or another.
A couple of quick asides: in general terms robotic arms are increasingly used on production lines for process automation and, more specifically within the 3D printing industry; 2016 is not the first time that robotic arms have been linked to additive processes.
Indeed, the very first time I saw a robotic arm being used for 3D printing was during a tour of Loughborough University some years ago, when I was privileged enough to witness some of the research and development at that academic institution focused on 3D printing with concrete materials. I was hosted by team leaders Dr Richard Buswell and Professor Simon Austin from Loughborough University’s School of Civil and Building Engineering, who introduced me to 3D printing on a whole new scale.
The research set-up, funded by the EPSRC and IMCRC, is based on a vast gantry system developed to explore the potential of 3D printing for architectural and construction applications with specially developed, high-performance concrete materials. The research has been ongoing for more than a decade to investigate the production of complex structural components – such as curved cladding panels and architectural features – that cannot be manufactured using conventional construction processes.
A key feature of this research involves looking into how increasingly complex building services infrastructure can be included within building structures at the point of construction rather than adding them by retrofitting post-construction, which is both time-consuming and costly. Most recently the Loughborough team embarked on an 18-month development programme with global project development and construction group – Skanska – to create the world’s first commercial concrete printing robot.
Since then there have been other robot arm / 3D printer concepts demonstrated for construction applications from organisations such as D-Shape and MX3D. However, no single system has been commercialised to date.
Direct and Indirect
However, at Formnext 2016 three of the 3D printing industry’s longest standing incumbents — 3D Systems, Stratasys and EnvisionTEC — were all demonstrating additive platforms featuring robotic arms that they have introduced through the course of the year. Stratasys’s two platforms, the Robotic Composite and Infinite-Build 3D Demonstrators, illustrate a direct and indirect 3D printing approach respectively, 3D System’s Figure 4 demonstrates an indirect approach, while EnvisionTEC was showing a wholly unique, direct 3D printing approach with a robotic arm combined with a proprietary print head for a binder jetting process.
With Stratasys’ Robotic Composite 3D Demonstrator, the blindingly obvious clue is in the name. When this concept was first introduced back in August, the emphasis was largely placed on the composites. I know that’s where my attention was drawn. However, the process itself is said to operate around 8 axes. There was actually some debate around this claim at the company’s press conference in Frankfurt, whereby someone was querying the legitimacy of 8 axes and positing that 7 was more accurate, due to the actual movement of the print platform relative to the 6-axis robot arm. It was nuanced stuff but, regardless, it’s notable degrees of freedom more than the three offered by traditional 3D printers, and only possible through the utilisation of a sophisticated robotic arm.
The actual additive process is still Stratasys’ Fused Deposition Modelling process, facilitated by an extruder. The novelty of the system comes from the new freedoms introduced by the flexible robotic arm and the strength of the materials that can be processed.
The second demonstrator concept that Stratasys also introduced this year, at the same time, is the Infinite-Build 3D Demonstrator, with a system set-up that also includes an industrial robotic arm. In this instance however, the robotic arm does not facilitate the actual process of 3D printing, rather it is used indirectly to enable a manufacturing solution by automating material handling (plastic pellets — not filament) for the printing process, which, theoretically, and as the name suggests, can be infinite.
Another recent embodiment of direct 3D printing with a robotic arm that I have witnessed came from a rather unexpected source — EnvisionTEC — in the form of the RAM123 3D printer. On the politics first, this platform development is the result of a partnership between Michigan-based Viridis 3D and EnvisionTEC. The partnership is definite, to what depth is a little more shrouded in mystery. One of my sources at EnvisionTEC suspects that it might have been an out-right buy-out, but that is unconfirmed.
What is in no doubt whatsoever is that this is a whole new 3D printing concept, utilising a proprietary inkjet print head attached to an ABB robot arm and executing binder jetting technology in a wholly unique way — without any physical constraints such as a box.
The proprietary print head deposits layers of sand and liquid binder materials during each pass onto a print platform to create geometrically complex sand molds and cores. This tech is still in the early stages of commercialization, and currently has build size constraints but clearly it offers huge potential for scalability. It was interesting to learn that the founder of Viridis — one Jim Bredt — has a history with the binder jetting process and was a cofounder of Z Corporation (a brand that doesn’t exist anymore but everyone still uses!)
Finally, 3D Systems’ modular additive manufacturing end-to-end solution, the Figure 4, is another not yet commercialised concept that incorporates one or more robotic arms. Once again, this is not direct 3D printing using a robotic arm. The actual 3D printing process within the entirety of the Figure 4 configuration is Digital Light Processing (DLP). It is a continuous iteration of the process (similar to that developed by Carbon), and what it enables 3D Systems to do with a resin process that it hasn’t done before is process reactive materials. This, in turn, means increased strength and durability in the material properties of the final part.
The Figure 4 uses the robotic arm(s) in a much more traditional manufacturing sense —compared with the above — to automate the end-to-end process of manufacturing by moving parts from the build platform, through post-processing and (optionally) inspection operations. So, while the 3D printing part of the process takes place within a resin pool, a fundamental necessity of the DLP process, the Figure 4 is more about a holistic approach to 3D printing to facilitate high volume series plastic production. According to 3D Systems the Figure 4 offers production parts on a par with injection moulding both in terms of quality and quantities.
Final Word ….. For Now
As 2016 closes out, it is fascinating to see how similar but very different solutions with robotic arms have emerged from disparate sources. One does sense that this is only the beginning of the cross over between additive technologies and robotics — and that together the positive disruption to manufacturing processes will only increase.