Cost-effective printing of 3d objects with skin-frame structures

the cost of material used in printing it. The frame structure is designed to meet various constraints by an optimization scheme. In (b) we remove the front part of the skin in order to show the internal structure of frame. (c) is the photo of an printed model by removing part of its skin to see the internal struts. (d) is the photo of the printed model generated by our method. A small red drawing pin is put under the object as a size reference in (c) and (d) respectively. The material usage in (d) is only 15.0 % of that of a solid object. 3D printers have become popular in recent years and enable fabri-cation of custom objects for home users. However, the cost of the material used in printing remains high. In this paper, we present an automatic solution to design a skin-frame structure for the pur-pose of reducing the material cost in printing a given 3D object. The frame structure is designed by an optimization scheme which significantly reduces material volume and is guaranteed to be phys-ically stable, geometrically approximate, and printable. Further-more, the number of struts is minimized by solving an `0 sparsity optimization. We formulate it as a multi-objective programming problem and an iterative extension of the preemptive algorithm is developed to find a compromise solution. We demonstrate the ap-plicability and practicability of our solution by printing various ob-jects using both powder-type and extrusion-type 3D printers. Our method is shown to be more cost-effective than previous works