Tool Path Generation, for Complex Surface Machining, Using Point Cloud Data

Abstract

This paper gives a detailed explanation of the project, related to reverse engineering, which was conducted by the authors of this paper. The project was based on direct machining, which is done by generating efficient tool paths directly from point cloud data, stored in STL format. The primary objective was to achieve high efficiency in the machining of free-form surface geometries, having complex machining areas. Reverse engineering traditionally involves surface fitting. However, it has several drawbacks. To overcome these drawbacks, the concept of direct machining is used. This skips the surface fitting process and consists of three main steps: digitizing, tool path generation and machining. Therefore, an algorithm to generate tool paths for direct machining was developed. The algorithm works for three-axis milling, using a ball-end mill cutter. It includes dividing the surface into ranges and generating B-spline curves which are best fit curves within each range. These curves are the required tool paths. A few case studies have also been conducted using this algorithm.

Integrating layer by layer manufacturing for the realization of polymer complex geometries with scanning devices: re-building by digital data

“…Further methods are available in literature, but strictly dependent on the compatibility among the softwares and among the machines to describe the complex shapes starting from the surface information supplied in terms of control nodes [1,[12][13][14][15]. In fact, the control points or nodes when considered in a clear way can be effectively used to generate the desired surface in particular for CNC processing [5,[14][15][16]. If not, the meshing technique based on the triangulation is very useful because the list of nodes and the normal position can be better readable by different softwares and neglects some other not required information that are very important only ESAFORM 2021.…”

Analysis of a novel tool path generation method for corrective machining in ultra-precision diamond turning based on point clouds

“…Besides, there are machining applications which are forced to handle the surface to be machined defined by (non-uniform or uniform) point clouds. An example is machining related to reverse engineering, where surface information typically consists of coordinate points gained by 3D scanning (as stated in [11,12]). The same applies for corrective machining of surfaces, where the actual measured surface form is mainly available as point cloud as well.…”

Algorithm for Micro‐Profiling from Image of the Injection Molds Complex Surfaces

“…[ 8 ] For simple NC programs, for the curve paths, coordinates of pixels in image were converted to line segments (vectors) with a contour tracing technique. [ 9 ] A descriptive model of the replication process has been developed, taking into account the thickness of the frozen layer during injection. The expected dependencies were proven by systematic injection molding tests with geometric surface microstructures, having depths of 45 or 100 µm and widths from 400 to 2000 µm, that were replicated into highcrystalline polypropylene and polycarbonate.…”