Scrappy: Using Scrap Material as Infill to Make Fabrication More Sustainable

Ludwig Wilhelm Wall, Alec Jacobson, Daniel Vogel, Oliver Schneider
2021 Proceedings of the 2021 CHI Conference on Human Factors in Computing Systems  
Figure 1 : Scrappy is a system that lets users use scrap objects as infll to reduce time, cost, and material: (a) a library tracks scrap objects, like an old print, as well as other common objects; (b) an add-in for Fusion 360 suggests scraps from the library that can ft into a model, sorted by saved printing time; (c) an algorithm fnds the best scrap placement and generates a modifed model; (d) a custom slicer optimizes infll and adds machine commands to pause the printer with instructions how
more » ... to insert the scrap into the object; (e) the fnal printed object has the scrap inside, reducing the material, time, and energy needed to print. ABSTRACT We present a software system for fused deposition modelling 3D printing that replaces infll material with scrap to reduce material and energy consumption. Example scrap objects include unused 3D prints from prototyping and calibration, household waste like cofee cups, and of-cuts from other fabrication projects. To achieve this, our system integrates into an existing CAD workfow and manages a database of common items, previous prints, and manually entered objects. While modelling in a standard CAD application, the system suggests objects to insert, ranked by how much infll material they could replace. This computation extends an existing nesting algorithm to determine which objects ft, optimize their alignment, and adjust the enclosing mesh geometry. While printing, the system uses custom tool-paths and animated instructions to enable anyone nearby to manually insert the scrap material.
doi:10.1145/3411764.3445187 fatcat:fbhn2dd6yreu5f2x2n7hrbc7d4