Connected Fermat Spirals for Layered Fabrication with FDM-Printers

This work discusses the implementation process of the algorithm presented in Connected Fermat Sprials for Layered Fabrication[8]. Layered fabrication is an addaptive manufactoring process that describes a set of techniques to construct 3D objects. In comparison to casting, molding or milling, these techniques are used to create unique individual parts layer by layer using a 3D printer. Sometimes, these parts would not even be generatable by conventional approaches. The algorithm[8] is designed for fused deposition modeling(FDM) in particular but without limitation. FDM is a technique that uses heated filament and a movable nozzle to create lines of viscous, fast hardening printing material. These lines form a 2D layer representing the shape of the object at the respective cross-section and can also be refered as the tool path. By creating the next layer on top of the current one, the printer eventually generates the final 3D Object. The composition of the toolpath directly influences the quality of the resulting product as well as the overall printing time[8]. There are different approaches to create such a tool path and using connected fermat spirals is one of them. To explain the motivation behind the Fermat Spiral approach and discuss the method as well as some disagreements on the used definitions and possible work arrounds, the next chapter lays the groundwork and defines some general concepts. Afterwards, the algorithm and the implementation process is described and finally the results are discussed in the conclusion. The overall implementation process took longer than expected and did not come to a satisfying completion. The reasons for that are described and evaluated in the following chapters. The original goal to validate and compare printing results from the underlying algorithm was not reached. The new aim of this work is to describe the obstacles found during the implementation process and present solutions as well as an outlook for more possible extensions. It should lay the basic groundwork for future investigations and implementations regarding this topic.