Improved intermediate point curve model for integrating reverse engineering and rapid prototyping

Direct integration of reverse engineering and rapid prototyping removes two intermediate steps of surface fitting from point cloud data and STL file generation from CAD models. Therefore errors introduced due to surface fitting and triangulations are eliminated and also the process of STL data validation and repair is avoided. Intermediate point based curve model (IPCM) method is one of the promising approaches for direct integration of reverse engineering and rapid prototyping however this approach has the limitation that it cannot handle objects, which result in multiple contoured slices. Moreover, IPCM based method is implemented with layers of constant thickness slices, and adaptive slicing with this method is not attempted. The present work is an attempt towards improving the capabilities of IPCM based method by overcoming the above-mentioned two limitations. The new system developed here has been tested on many parts, which demonstrates the capability of the proposed system. An erratum to this article can be found at     

鼠标曲面点云数据处理及快速原型制作研究

以鼠标为研究对象,实践了逆向工程技术与快速原型技术相结合的工艺方法。在逆向工程中应用SURFACER软件处理三维激光扫描仪测量得到的鼠标点云数据,进而使用三维造型软件Pro/E对其进行了曲面重构,获得了所需的鼠标实体模型,为新产品开发预评估、新产品有限元分析等提供了宏观模型,可减小新产品开发过程中遇到的风险。     

Direct integration of reverse engineering and rapid prototyping based on the properties of NURBS or B-spline

As product varieties increase and life cycles shorten, the need to reduce product development time becomes more critical to maintain competitiveness in the market. The reduction of the product development time, therefore, requires revolutionary improvements rather than gradual changes in technology. Based on a novel strategy the procedure for integration of reverse engineering and rapid prototyping was developed in this paper. Direct integration of reverse engineering and rapid prototyping is not a new issue and its importance has been demonstrated by many authors. However, all traditional algorithms for integration of RE and RP operate on scattered points directly such that some useful information for example curvature, normal and geometric shape, which are necessary for adaptive slicing in RP, cannot be obtained. To resolve the difficult dilemma a new algorithm is developed to build a bridge between scattered points and adaptive slicing.     

Re-triangulation in STL meshes for rapid prototyping and manufacture

The main objective of this research is to identify ways to simplify the STL meshes, while simultaneously maintaining the accuracy of the STL file. It demonstrates a technique to simplify large and complex STL triangular meshes and to optimise STL shape for rapid prototyping and manufacture. STL mesh re-triangulation can be separated into two processes, i.e., mesh deletion and mesh rearrangement. In the mesh deletion process, two kinds of weighted-value ratio algorithms can be chosen for determining the suitable value of STL mesh deletion. A genetic algorithm that incorporated fitness functions was used for the optimisation of the rearranged STL meshes. Two case studies of STL mesh reconstruction, which examine the effects of the algorithms, are presented. These studies show that optimisation of the shape of the STL file reduces its size, resulting in a reduction of the fabrication time and improvement of the rapid prototyping process.     

The design and manufacturing of porous scaffolds for tissue engineering using rapid prototyping

This research paper addresses the issue of developing an efficient methodology to design and manufacture a complex scaffold structure of desired porosity required for tissue engineering applications using a novel approach based on fused deposition modelling (FDM) rapid prototyping (RP) technology. The scaffold provides a temporary biomechanical structure for cell growth and proliferation to produce the required body parts. Conventional techniques of scaffold fabrication (such as fibre bonding, solvent casting and melt moulding) generate scaffolds with unpredictable pore sizes due to their limitations in flexibility and control of pore volume and distribution. Moreover, such scaffolds have poor mechanical strength and structural stability. The paper describes an FDM pre-processor that ensures the fabrication of scaffolds of desired porosity and inter-connectivity on the FDM system.     

Process chain development for the rapid prototyping of microstructured polymer, ceramic and metal parts: composite flow behaviour optimisation, replication via reaction moulding and thermal postprocessing

Different variants of reaction moulding techniques exploiting the rapid light-induced photopolymerisation of reactive resins are widely used in microsystem technologies for the fabrication of plastic components or for rapid prototyping (RP) purposes. In this paper, the further development of micro reaction moulding with respect to a rapid prototyping of ceramic and metal parts will be described. As in powder injection moulding, the process sequence binder–filler–formulation, replication, debinding and sintering has to be passed. The mould filling and, hence, the accurate reproduction of surface details depend strongly on the composite’s viscosity, which is a function of the filler load. Especially, an improved process control of the composite formation prior to moulding and the thermal debinding is crucial for the realisation of microstructured ceramic or metal parts. The development of the whole process chain and some examples will be presented. This paper was originally presented at the International Conference on Multi-Material Micro Manufacture (4M), Karlsruhe, Germany, 29 June 2005 to 1st July 2005, and is extended for publication in this journal.