First 3D-print then turning

by Thomas Masuch

Additive manufacturing: The post-processing of printed components also offers enormous opportunities for machining companies

2019/07/15 - Double-digit annual growth rates ensure that the industrial 3D printing market is becoming more and more attractive economically. This is no longer the case only for companies that specialize in additive manufacturing and supply 3D printers or materials, but also for machining companies.

Especially in the additive manufacturing of metal parts, the components are rarely used as they come out of the machine and usually require post-processing. In addition to the frequent removal of support structures, this also includes surface treatment and classic machining such as turning, milling, drilling and tapping. Depending on the component, the application and the requirements of the industry, the post-processing can be very time-consuming, and in some cases even generate a significantly higher added value than the actual »3D printing« of the component.

As new technologies for industrial 3D printing are introduced to the market, the requirements and possibilities for post-processing are also expanding. And the growing number of materials that can be processed additively (such as Inconel, Hastelloy, titanium, aluminum, tool steel or various stainless steels) also increases the demands on post-processing.

Combining know-how

This can also be seen in a Deutsche Bahn project which, together with the manufacturing company Rolf Lenk and the machine manufacturer Gefertec, produces additively manufactured spare parts for locomotives from the 1960s and 1970s. The steel wheelset bearing caps with a diameter of 374 millimetres, weighing around 12 kilograms, are first produced by Rolf Lenk in Ahrensburg, North Germany, using wire deposition welding (3DPM). In a further step, the components are turned and brought to the exact dimensional accuracy and surface quality. Rolf Lenk benefits from the fact that it has many years of experience in machining and combines this know-how with additive manufacturing.

A further example from Rolf Lenk shows just how versatile »turning« has become in the post-processing of additive components: four titanium wheel suspensions were produced in the SLM process on a SLM 280 machine and used in the electric racing car »e-gnition EGN19« at the Technical University of Hamburg (TUHH). The inner radius of the wheel suspensions was machined on the lathe.

Seizing opportunities

These examples illustrate how important machining know-how is for industrial 3D printing and what opportunities this offers for companies that are originally at home in the field of turning and milling. Only those who have mastered the entire process chain can take full advantage of this state-of-the-art manufacturing process. The first port of call for this is Formnext. Here machining companies meet highly qualified trade visitors (2018: 26,919) - including decision-makers from international manufacturing companies from numerous sectors ranging from medical technology to gas and oil exploration to the aviation industry. At Formnext, they are also on the lookout for partners with whom they can further develop their own manufacturing potential.