Adaptive direct slicing with non-uniform cusp heights for rapid prototyping

Abstract

Adaptive slicing varies layer thickness by taking the geometry change of the CAD model in the build direction into account to improve surface finish. Direct slicing generates exact slice contours from the original CAD model and avoids an intermediate representation, known as an ''STL file''. At present, most direct slicing approaches are restricted to some CSG solids or some CAD systems. In this paper, an approach toward adaptive direct slicing with non-uniform cusp heights independent of CAD systems for rapid prototyping is presented. First the geometry model is imported into the adaptive direct slicing system from CAD systems using the standard STEP format. Using OpenGL graphics libraries, the solid model is then displayed and the user is prompted to specify the allowable cusp height for each highlighted surface. Lastly, the CAD model is sliced adaptively with different cusp heights (tolerance requirements) for different surfaces. With non-uniform cusp heights, adaptive slicing has a higher efficiency. Implementation details and results are also presented.

Efficient slicing procedure based on adaptive layer depth normal image

“…Sabourin et al [8] adopted the cusp height as a criteria and computed each slab thickness by recursive subdivision until the layers thickness under a given tolerance. This was further extended by Yan et al [9], who obtained a higher efficiency using a non-uniform cusp height as a criteria. Mani et al [10] proposed a region-based adaptive slicing, where the given model surface is classified into critical surfaces which are adaptively sliced, and non-critical surfaces, such as part interior, which are sliced using the maximum allowable layer thickness.…”

Review of heterogeneous material objects modeling in additive manufacturing

“…Based on the concept of limited area deviation [114], a direct slicing algorithm was implemented using AutoCAD. For rapid prototyping, an adaptive approach was presented with non-uniform cusp heights independent of CAD systems [115]. Based on an NURBS model, a ray-tracing method was developed for direct slicing [116].…”

“…Within each layer, 2D material gradients are designed by subdividing the 2D shape into several sub-regions enclosed by Fig. 12 Some current slicing methods: Adaptive slicing results (a) [113], (b) [115] and (c) [118]; direct slicing results of NURBS models (d) [117], (e) [120], and T-spline models (f) [120]; direct slicing results of trivariate NURBS models (g) [64], and trivariate T-splines (h) [121] Li et al Visual Computing for Industry, Biomedicine, and Art (2020) 3:6…”

Surface slicing and toolpath planning for in-situ bioprinting of skin implants

“…Additionally, the printed fibre layup arrangement is known to affect the mechanical integrity of the object [19,20]. The use of adaptive slicing can reduce the stair-casing effect of planar printing by creating non-uniform build layers by adjusting the layer thickness according to the shape of the object being printed [21][22][23]. Another strategy to reduce the effects of planar printing is to slice the object with multi-directional tool paths, dividing it into different regions that are printed in different orientations [24,25].…”