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

Abstract

Figure 1: Given an input Horse model (a), our method generates a skin-frame structure (b), which is approximate to the model, to minimize 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. Abstract3D printers have become popular in recent years and enable fabrication 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 purpose 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 physically stable, geometrically approximate, and printable. Furthermore, 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 applicability and practicability of our solution by printing various objects using both powder-type and extrusion-type 3D printers. Our method is shown to be more cost-effective than previous works.

Cross section-based hollowing and structural enhancement

“…Second, our adaptive hollowing algorithm is mainly suitable for the model whose internal space needs to be reused. If users want to generate an object with light weight structures inside, our algorithm is not as good as [36,14,42].…”

“…Wang et al [36] use frame structures to fill the interior of the model with the constraints of stiffness and strength, static stability, printability, etc. Similarly, the work by Zhang et al [42] uses medial axis tree instead of frame structures, which can naturally transfer the external loads from different directions to the inner core structure.…”

“…Although several algorithms have been proposed to design light-weight structures for the purpose of reducing material usage, here we only compare with the algorithm [36] to evaluate our system. Because this method is the most close to our work.…”

“…We compare the material cost with their algorithm under the similar structural strength. In [36], the external force for the Hangingball model is set to 10N, so γ in formulation(9) is set to 1.0kgf . Figure 11(a) is generated by [36], and its volume is 3.940 × 10 4 mm 3 .…”

“…In [36], the external force for the Hangingball model is set to 10N, so γ in formulation(9) is set to 1.0kgf . Figure 11(a) is generated by [36], and its volume is 3.940 × 10 4 mm 3 . While the volume of the model generated by our system (Fig.…”