Fachbereich Informatik

Multi-material support in OpenSCAD

Bachelor-Thesis at group TAMS


While most low-cost 3D-printers are still limited to a single tool, affordable multi-material FFF/FDM machines are entering the market recently. For example, the Prusa i3 MMU printer uses a simple multi-material feeder to select from up to five different filaments at runtime, while the E3D Toolchanger can be equipped with up to four different tools, one of which is active at any time.

However, the required design and slicing software for multi-material 3D-printing is still an open question. Recent versions of PrusaSlicer already provide options for automatic filament retraction and exchange, with dumping of excess material outside the actual printed object. This works well for the small set of provided demo objects, but even loading a multi-material object for printing is not trivial, as the common STL file format does not support (volumetric) material annotations.

In this thesis, we will look at proposed approaches to model and export multi-colored and multi-material 3D designs in the open source tool OpenSCAD. The tool already supports colors as object attributes, and it seems straightforward to map specific colors to user-defined materials when exporting a design. The goal of the thesis is to develop a full 3D-design tool-chain that allows the user to interactively create multi-colored objects and to export those objects in formats suitable for automatic printing on the Prusa i3 MMU and/or E3D toolchanger machines.

The precise scope of the software implementation is to be discussed, with a basic functionality achievable in a BSc-thesis. Given the current Corona restrictions, large parts of the software can be designed (and tested) at home, but access to a 3D-printer would of course be a plus.

Thesis Goals: