The Council for Scientific and Industrial Research’s (CSIR’s) 3D metal printer – the largest of its kind in the world – is being used for a number of projects, including components for the Ahrlac, Marlin missile and Armscor.
Done layer upon layer, the process (also known as additive manufacturing) starts with designing a 3D computer-aided design and drafting (CADD) model and associated design file. In the CSIR’s case an STL (stereolithography) file then gets transferred onto the 3D printing machines software. The machine then translates that design into multiple layers, depending on the desired layer thickness and begins printing out layer by layer.
The 3D printer uses a powder bed fusion process called selective laser melting where a 5 kW laser melts titanium powder. A bed of powder is added for each layer and the subsequent layers are fused through the selective laser melting. The machine prints from 2 000 layers up to 10 000 layers.
The CSIR’s 3D printer is able to use a variety of metals but it is currently using titanium. The CSIR’s printer is currently the biggest in the world in terms of printing size (.6x.6.x2 metres) and is able to print faster than other 3D printers due to it being able to print up to four different designs at the same time. The 3D printer has been created through Project Aeroswift. The project was developed and driven by a group of CSIR researchers and a team from Aerosud. The printer was funded by Department of Science and Technology (now the Department of Science and Innovation) and when asking how much the printer cost, Senior researcher at the CSIR, Dr Ntombi Mathe, stated it was well over R100 million.
CSIR researcher, Londiwe Motibane, stated that the advantageous side to 3D printing is that complex designs are able to be printed, printing can be faster than other forms of manufacturing, and that there is less waste than in traditional manufacturing methods.
In an interview with Mathe during a CSIR event on Tuesday with the theme “Female researchers working with the world’s largest 3D printer”, Mathe told defenceWeb that the printer is involved in a number of on-going projects. Recently, the Project Aeroswift team worked with Denel to produce a Marlin missile boat tail (the exterior end of the experimental missile), for research purposes, which reduced a complex assembly of pieces into a single component, which resulted in weight reduction. Denel Dynamics is developing the Marlin as a radar-guided air-to-air missile.
More complex prints were on display at the event such as a .5x.5 metre topology optimised quadcopter (drone) frame. The frame was designed by Altair and was printed for a prototype drone by Aeroswift. The printer first began producing parts in 2016 and this has included the condition lever grip and throttle grip as well as fuel strainers for the Ahrlac aircraft (the fuel strainer acts primarily as a fuel drain for water and small particles of sediment and is usually found at the lowest point of an aircraft’s fuel system). When pressed about the work done for the Ahrlac, Mathe stated that due to legal reasons the CSIR cannot comment on anything to do with the project.
Mathe did add, however, that there are several projects in the pipeline. One is with Airbus for an approximately two metre wing and another project is with Armscor for ballistics testing in their laser department. Aeroswift is also understood to have printed a fuel tank pylon bracket for a commercial aircraft.
The 3D printer’s current and on-going application in the defence industry, aside from the small completed projects, is still unclear yet Mathe stated they (the CSIR team) are in the process of gaining the relevant certification for the 3D printer to produce structurally integral parts for aircraft, specifically for Airbus.
The system has the ability to produce geometrically complex parts according to a customer’s specification, minimising material wastage while processing difficult-to-machine materials. The system can also be used to produce parts for the power generation, automotive tooling, defence and manufacturing sectors.
The event on Tuesday was split into a presentation on 3D printing at the CSIR, a stem cell research programme presentation and a presentation/exhibition of the world’s largest 3D printer. Stem cell reprogramming is the ability to reprogram stem cells which allows scientists to be able to turn any cell of the human body into a pluripotent stem cell. This has many benefits, one of which is making it possible to study and treat diseases.
Researcher Dimakatso Gumede works on creating disease models of the innate immune system to study unique African gene variants that lead to elite controllers that naturally control viral load levels without antiretroviral therapy. She said her research seeks to address adverse drug reactions observed in the African population due to genetic diversity.
In the spirit of women’s month, the event was presented by three female researchers at CSIR, two from 3D printing research and one from stem cell research backgrounds. “I was previously working in mining and I must say that it was difficult to compete as a female. Women should be allowed to showcase their talents at all times because they are very capable. Organisations such as the CSIR should be commended for the continued support to women professionals,” said Motibane.
“We are able to show that we can do just as well as our male counterparts and even better sometimes. But mostly this shows that science and engineering can be and should be done by anyone regardless of background, gender or race.”