Deon de Beer

Entry level RP machines: how well can they cope with geometric complexity?

Purpose – The purpose of this paper is to examine the limitations of entry‐level rapid prototyping (ELRP) machines when fabricating objects with high complexity.Design/methodology/approach – The literature review provides an overview of RP technologies, followed by a discussion on the different levels of complexity in objects. The paper continues with a discussion on the definition of ELRP, followed by a number of experiments to explore the limitations of an ELRP system when fabricating complex models, and to compare the results obtained with those from a professional RP machine using standardised build parameters and the same acrylonitrile butadiene styrene material.Findings – Of the five complex models that were produced from the Rapman machine, four of them were affected by warping; also, support structures were difficult to remove due to the interwoven build pattern. The study also found that the Rapman parts were coarsely built as opposed to the Dimension parts that were less coarse. The Rapman parts...

Development of a stereolithography (STL) slicing and G-code generation algorithm for an entry level 3-D printer

Additive manufacturing (AM) is a method that creates physical objects layer by layer. This paper presents a prototype STereoLithography (STL) slicing and tool path generation algorithm, which serves as a data front-end for an entry level three-dimensional (3-D) printer. Used mainly in AM, 3-D printers are devices that apply plastic, ceramic and metal, layer by layer, in all three dimensions on a flat surface. 3-D printers, unfortunately, cannot actually print an object without a special algorithm, required to create the computer numerical control (CNC) instructions (commonly known as G-code) for printing. Therefore, the STL slicing and tool path algorithm forms a critical component for AM. The purpose of this study was to develop an algorithm that is capable of processing and slicing an STL file or multiple STL files resulting in a tool path and finally generating a G-code file for an entry level 3-D printer.

Development of a Stereolithography (STL) input and Computer Numerical Control (CNC) output algorithm for an entry-level 3-D printer

This paper presents a prototype Stereolithography (STL) file format slicing and tool-path generation algorithm, which serves as a data front-end for a Rapid Prototyping (RP) entry- level three-dimensional (3-D) printer. Used mainly in Additive Manufacturing (AM), 3-D printers are devices that apply plastic, ceramic, and metal, layer by layer, in all three dimensions on a flat surface (X, Y, and Z axis). 3-D printers, unfortunately, cannot print an object without a special algorithm that is required to create the Computer Numerical Control (CNC) instructions for printing. An STL algorithm therefore forms a critical component for Layered Manufacturing (LM), also referred to as RP. The purpose of this study was to develop an algorithm that is capable of processing and slicing an STL file or multiple files, resulting in a tool-path, and finally compiling a CNC file for an entry-level 3- D printer. The prototype algorithm was implemented for an entry-level 3-D printer that utilises the Fused Deposition Modelling (FDM) process or Solid Freeform Fabrication (SFF) process; an AM technology. Following an experimental method, the full data flow path for the prototype algorithm was developed, starting with STL data files, and then processing the STL data file into a G-code file format by slicing the model and creating a tool-path. This layering method is used by most 3-D printers to turn a 2-D object into a 3-D object. The STL algorithm developed in this study presents innovative opportunities for LM, since it allows engineers and architects to transform their ideas easily into a solid model in a fast, simple, and cheap way. This is accomplished by allowing STL models to be sliced rapidly, effectively, and without error, and finally to be processed and prepared into a G-code print file.

Additive manufacturing as an enabler for enhanced consumer involvement

This paper draws on previous work by the authors that aimed to use functional prototypes, produced using additive manufacturing (AM), as a means to draw customer input and preferences into the development of new products. This technique is referred to as Customer Interaction through Functional Prototypes (CIFP). The CIFP philosophy has been proven in both consumer and medical products. In recent years, the authors have developed further concepts of AM-enabled enhanced consumer involvement within their respective research teams. This paper discusses the extended use of CIFP to develop innovative new product concepts in the Vaal University of Technology, to support grant- holders of the Industrial Development’s Corporation (IDC) Support Programme for Industrial Innovation (SPII) and the Technology and Innovation Agency (TIA). The paper goes on to discuss a novel method of consumer interaction developed at Loughborough University, referred to as a Computer-aided Consumer Design (CaCODE). This technique allows non- designers to take an existing product design (e.g., a pen) and modify its shape in real time, in order to create a customised version of the product that meets their needs. The modification is limited within pre-defined parameters to make sure that any final design is functional and can be produced using AM.

Conversion of a GIS surface data directly to a 3D STL part for terrain modeling

Purpose – This paper aims to convert surface data directly to a three-dimensional (3D) stereolithography (STL) part. The Geographic Information Systems (GIS) data available for a terrain are the data of its surface. It doesn’t have information for a solid model. The data need to be converted into a three-dimensional (3D) solid model for making physical models by additive manufacturing (AM). Design/methodology/approach – A methodology has been developed to make the wall and base of the part and tessellates the part with triangles. A program has been written which gives output of the part in STL file format. The elevation data are interpolated and any singularity present is removed. Extensive search techniques are used. Findings – AM technologies are increasingly being used for terrain modeling. However, there is not enough work done to convert the surface data into 3D solid model. The present work aids in this area. Practical implications – The methodology removes data loss associated with intermediate fil...

Direct generation of STL files from USGS DEM data for additive manufacturing of terrain models

ABSTRACT Geographical information system (GIS) data in digital elevation model (DEM) format contains surface data of terrain on the Earth. This surface data needs to be converted into a 3D faceted file before uploading to an additive manufacturing (AM) machine. Commercially available software packages perform this task indirectly by translating and modifying data through different file formats. This paper discusses a methodology to convert the United States Geological Survey (USGS) 7.5-minute and 1-degree DEM file formats directly to 3D stereolithography (STL) ASCII format. A software program in C is developed to create a base and walls around the surface data to make a 3D STL part of the terrain. The STL file was uploaded to an AM machine (EOSP395) to fabricate a physical scale model of the terrain. This work not only removes intermediate steps and the associated data loss but can generate an STL part in relatively less time.

PHYSICAL PROPERTIES OF SAND PARTS PRODUCED USING A VOXELJET VX1000 THREE- DIMENSIONAL PRINTER

Successful case studies of metal casting applications using sand moulds and cores produced by additive manufacturing (AM) processes have been widely reported in the literature. The layered- based manufacturing process has revolutionised traditional sand moulding methods. This is essentially due to the numerous advantages of AM, including the reduction of design lead time and the ability to manufacture objects with complex geometry in a rapid turnaround time. Locally-available AM processes that are capable of producing sand moulds and cores include laser sintering (LS) and three-dimensional printing (3DP), with the latter AM process growing in dominance over the former. However, a better understanding of the properties of parts produced by AM processes is required in order for the processes to be fully adopted by the foundry industry. Crucial characteristics of 3DP sand parts related to strength, dimensional accuracy, and hardness are not well- known in terms of their magnitude and in comparison with conventionally-moulded sand parts. In this investigation, the physical properties of test specimens produced under standard manufacturing conditions, using a Voxeljet VX1000 machine, were assessed for bend and tensile strength, hardness, friability, and surface finish. The physical properties of the 3DP test specimens were then compared with the properties of laboratory hand- rammed test specimens. The results of the investigation suggest that the properties of AM-fabricated sand parts are inferior to sand parts produced by conventional moulding processes.

HySA infrastructure center of competence: A strategic collaboration platform for renewable hydrogen production and storage for fuel cell telecom applications

The Department of Science and Technology of South Africa developed the National Hydrogen and Fuel Cells Technologies (HFCT) Research, Development and Innovation Strategy. The National Strategy was branded Hydrogen South Africa (HySA). HySA has been established consisting of three Competency Centres - HySA Infrastructure, HySA Catalyst and HySA Systems. The scope of the Hydrogen Infrastructure Competency Centre (HySA Infrastructure CoC, [1]) is to develop applications and solutions for small- and medium-scale hydrogen production and storage through innovative research and development. The aim of this paper is to present an overview of the HySA Infrastructure CoC projects related to renewable hydrogen and fuel cell applications. The presentation will discuss how the HySA Infrastructure could assist telecommunication industry with providing a potential strategic platform for developing and testing various hydrogen generating solutions for fuel cell applications specific to African conditions. More specifically, the following enablers will be discussed: existing active projects for hydrogen production: solar-to-hydrogen demonstrations based on PEM electrolysis, ammonia-to-hydrogen projects for telecom, advanced PEM electrolysis concepts (high-current density operation), hydrogen storage, safety and codes, as well as close proximity of HySA Infrastructure to Gauteng, an economical hub of South Africa, commercialization road map, activities towards establishing “Platinum Valley” SEZ (special economic zone for Pt-related activities).

Using Idea 2 Product Labs® as a strategy for accelerating technology transfer

Technology transfer poses particular problems to developing countries whose governments cannot always afford to fund expensive high-tech solutions. This article reports on the Idea 2 Product Labs® concept that was developed in South Africa to offer a low-cost open-source alternative. The motivation behind the work was to put innovative new technologies into the hands of more people within a shorter timeframe than would otherwise be possible. The background, planning, objectives, outcomes and impact of the project are reported together with some conclusions on how this model could be adopted across a wider domain.