3D printing, also known as additive manufacturing, is an iterative production method that has risen from the basement to factory in just a couple of decades. In the year 2020, 3D printing in the automotive sector is rampant. From established OEMs to fresh start-ups, it seems like everyone wants a piece of the additive cake. While 3D printing non-critical decorative pieces have been done for some time now, manufacturers are slowly but surely making their way into engine components too.

The design freedom granted by the technology makes it perfect for highly complex bespoke prototyping. As it stands, however, the vertical and horizontal integration of AM into current industrial manufacturing lines for mass production is generally difficult due to a lack of standards. The standards aren’t in place due to the relative infancy of AM-specific workflows and processes such as post-processing and part transport.

On the digital side of things, there is a lack of transparency, a proneness to errors, and limited process chain monitoring capabilities. This is a result of a lack of interface continuity in the horizontal digital data chain. 3D printing in the automotive sector has been limited to prototyping thus far, but things are changing.

The POLYLINE project

Leading the mass production charge would have to be the POLYLINE project, a lighthouse project bringing together 15 industrial and research partners from across Germany to develop a digitalized additive manufacturing production line specifically for serial automotive parts made of polymers. Initiated in May of this year, the project has received a total of €10.7M in funding from the German Federal Ministry of Education and Research and is set to take place over the course of three years.

The idea is that by complementing traditional manufacturing techniques with industrial-grade AM technology, partners, which include 3D printer OEM EOS and the BMW Group, should be able to produce several high-throughput production line systems for the industry. To consider the project successful, partners will have to develop a “breakthrough” system covering both the digital and physical aspects of manufacturing.

All individual sub-processes, including preparation, SLS printing, cooling, unpacking, cleaning, and post-processing will be automated and integrated into the production line. According to EOS, this will be the first time all the individual elements of an SLS production line will be linked together in one continuous automated chain – truly a piece of history in the making.

The other major partners in the project include 3D printing software solutions provider Additive Marking GmbH and Munich-based post-processing specialists DyeMansion,

3D printing in the automotive sector

So who are the manufacturers that have been making use of the technology until now? To kick things off, Continental AG recently installed a Stratasys Fortus 450mc FDM 3D printer at its Additive Design and Manufacturing (ADaM) Competence Center in Karben, Germany. Although famous for its tyres, Continental also produces engine parts and provides mobility services through its Continental Engineering Services (CES) division. The company cites cost-effectiveness, high throughput, and electrical safety as key factors to its manufacturing success, which it reportedly sees in Stratasys’ 3D printing technology.

Elsewhere, in LA, start-up Czinger is set to launch its first 3D printed hypercar, the 21C, in 2021. The mostly hand-assembled vehicle is expected to sell at an eye-watering $1.7M and will be fully street legal in the US. The manufacturer plans to only produce 80 models and cites savings in weight, cost, and time as the main factors in its decision to employ powder bed fusion technology from the well-established SLM Solutions.

BMW has also opened its new additive manufacturing campus, which will bring together prototyping production and series production under one roof. The objective is to industrialize 3D printing methods for automotive production.

In the motorsport world, Chevrolet’s racing division recently announced that its teams had raced over 80,000 miles, this season alone, in cars fitted with 3D printed parts. The racing division comprises the brand’s Corvette, INDYCAR, NASCAR Camaro, and Silverado teams, with the 3D printed components including oil tanks, air conditioning cooling boxes, integrated hydration systems, headlight assemblies, and even power steering pump brackets.

Spare parts on-demand

A single car contains about 30,000 individual components, many of which have the potential to break, crack, or fail in some way. The original manufacturer may not always have spares for those parts in stock, especially when it comes to older models. According to leading 3D material jetting company Stratasys, the additive manufacturing of these spare parts could reduce lead times by up to 90% while reducing costs by up to 60%. With failing components, a spare part manufacturer rarely needs to go down the mass production route, unless every model of the car has the same problem (in which case the OEM needs to call the design team in for a serious meeting). Using the tool less additive process, the production line itself can be omitted, and the spare parts can be fabricated as and when needed, so the time and money savings are no surprise at all.

3D printable tooling

Alternatively, in cases where the mass production of these spare parts is necessary, 3D printing can also be used to create the jigs and fixtures used on the production line. 3D printing companies have even started formulating 3D printable materials specifically for production tooling.

In EOS’ case, this is the newly released ToolSteel 1.2809. It is an ultra-high-strength maraging steel designed for high-stress molding applications. The 3D printing steel features excellent fatigue resistance and improved polishability, and its properties can be fine-tuned with heat treatments after 3D printing. The recommended applications include plastic injection molding, extrusion tools, hot pressing tools, and die casting tools. In what can be seen as an ‘indirect’ benefit of 3D printing, the tooling made of this steel would enable the mass production of other parts on a conventional production line.

Future of Industrialisation of 3D printing looks bright

It’s clear then, just how vast the application of additive manufacturing is in automotive, whether it be for polymer, metal, or ceramic parts. Many manufacturers have already realized the potential of the technique, and continue to use it for prototyping purposes. With projects such as POLYLINE, however, we will undoubtedly see the shift to mass production happen at an ever-increasing rate.