The goal of this graduation project was to investigate if 3D printing could serve as a promising alternative for manufacturing spare parts needed for the re-manufacturing of diesel injection pumps. This project was conducted under the EU ReCiPSS project, along with the support of Robert Bosch GmbH. The proposition was investigated on three levels and posed the following research questions:

1.Can 3D printing produce spare parts for the pump at an acceptable cost and quality level compared to the existing manufacturing methods? (Feasibility)
2.Does spare part 3D printing make business sense for the Automotive Aftermarket Division of Bosch to pursue as a remanufacturing strategy? (Viability)
3.Is 3D printing for spare parts more environmentally friendly compared to the existing manufacturing methods? (Sustainability)

To answer these questions for the entire VP30 pump and fuel injection pumps in general would have been difficult. Thus, tools such as the Disassembly Map and the Hotspot Mapping tool were used to identify potential parts within the pump for which this initial investigation could take place. Using functional importance and environmental impact as criteria, the selection of two parts, an aluminium Locking Cover and an alloy steel Cam Plate were made.

Visits to the remanufacturing facility and Bosch’s 3D Competence Centre opened doors to investigate the technology, its limitations, organisational barriers, and future potential. The metal printed parts arrived and were analysed on the three pillars mentioned.

The investigation found that metal 3D printed parts can meet the desired performance specifications. However, post-processing treatment such as annealing, case hardening and some machining might be required for specialised functions. The costs of metal 3D printing are not yet competitive with conventional manufacturing and are viable only for specific scenarios. These scenarios take the shape of lack of suppliers, urgent part demand, high tooling costs, and so on. Moreover, the non-competitive cost also brings to fore the organisational barriers within Bosch. Primarily, the automotive release procedure which requires significant investment of time and money to make a change. Lastly, on the sustainability front, middle volume production (~200-1000 units) was shown to be more sustainable than conventional manufacturing for the same volume.

The investigation shows that in 2022, 3D printing metal spare parts is feasible but needs specific scenarios to be viable and sustainable. However, with improvements in technology and greater acceptance of 3D printing as a core industry technology, these pains can be resolved and allow for better and long-lasting products with lesser environmental impact. The advent of the 2030’s will be exciting in this regard.