Methods to reverse engineer spare parts

The introduction of additive manufacturing allows to picture a new supply chain for spare parts. In this new model the concept of digital spare parts is defined. The only information needed to reproduce a part using additive manufacturing technology is a ready-to-be- produced 3D model, that already contains manufacturing instructions. The scope of this work is to present reverse engineering methodologies to obtain a ready- to-be-produced 3D model from each of the possible single and combined input data available of a spare part: 2D paper drawing, 2D digital drawing, the physical spare part or the physical mold/tool used to produce it and nominal 3D model and their combinations of interest. The pieces of equipment used in this work are three different CAD modeling software (SolidWorks 2018, PTC Creo 3.0 and Siemens NX 11), a structured light- stereovision 3D scanner and two specific reverse engineering software (Scan2CAD v10 and Geomagic Design X 2018). The reverse engineering methodologies are defined after a research on the scientific literature is accomplished. For each of the inputs aforementioned one or more procedures to obtain the final 3D model are proposed. In the experimental phase, different versions of a recoil starter were used as spare parts to be reversed engineered. The methods defined for single input cases were tested to acquire real-life results and to define their effectiveness. The results obtained were time needed to perform the reverse engineering task, advantages and disadvantages of the procedure tested. These are discussed in order to propose further developments and to evidence where the processes can be enhanced. All the methodologies defined and tested demonstrated to be operational to accomplish reverse engineering of spare parts, aside from vector image-aided CAD modeling, where the conversion from 2D paper drawing to 2D digital drawing was proved not sufficiently accurate. In conclusion, this thesis work defined a standardization of the methods to obtain a ready- to-be-produced 3D model of a spare part from every possible starting piece of information available.