Browsing by Author "Oberholzer, J. F."

Now showing 1 - 6 of 6
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    Evaluation of resource efficient process chains for secondary manufacturing processes of bamboo bicycles
    (Elsevier, 2017) De Weta, P.; Oosthuizen, G. A.; Oberholzer, J. F.; Burgera, M. D.; Ras, C. I.
    ENGLISH ABSTRACT: In order for manufacturing suppliers to stay competitive in the global market, innovative and resource efficient process chains need to be a part of the manufacturing strategy. Secondary manufacturing process steps entail the assembly and surface treatment manufacturing steps after the primary cutting and shaping of the components. Bicycles have an enormous effect on society, both in terms of socio-economics and of advancing modern industrial processes. In order to manufacture bamboo bicycle frames in South Africa innovative designs and process chains need to be developed. In this study process chains for secondary manufacturing processes of bamboo bicycles were developed and compared. The manual secondary process steps for manufacturing bamboo bicycles in Africa were mapped and compared with developed technological process chains in terms of resource efficiency. The effect on time and cost were evaluated.
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    Investigating the performance of custom manufactured cermet mounted points when grinding Ti6Al4V alloys
    (Central University of Technology, 2017) Enever, A. A.; Oosthuizen, G. A.; Sacks, N.; Burger, M. D.; Oberholzer, J. F.
    ENGLISH ABSTRACT: The use and implementation of mounted grinding points in industrial applications are wide spread, ranging from the bio-medical and automotive industries to the aerospace and mining industries. These smaller variants of the larger, more conventional grinding wheels are more affordable to produce, but equally effective in grinding applications. Generally, the abrasive materials implemented in the manufacturing of mounted points do not include the cermet WC-12-wt-%-Co, but rather use alumina- or silicon carbide. This study investigates the use of this WC-12-wt-%-Co cermet as abrasive medium. The resin was varied to manufacture two sets of cermet WC-12-wt-%-Co mounted points that contained 12-wt-% and 16-wt-% resin content, respectively. The grinding performance of these mounted points were evaluated in terms of the tool wear rate, the surface finish and the surface hardening of the Ti6Al4V work piece. The grinding tool wear rate of the 16-wt-% mounted points were more gradual than for the 12-wt-%. The 16-wt-% mounted points produced a smoother surface finish and work hardening occurred on most of the Ti6Al4V work piece surfaces.
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    Optimal machine parameters to maximize the accuracy of producing aluminum dovetails using WEDM
    (Elsevier, 2017) Oberholzer, J. F.; Oosthuizen, G. A.; De Wet, P.
    Dovetail joints are one of the strongest joining methods used to connect two perpendicular components together. Dovetail joints are predominantly used in wooden components but can also be found in other non-wood components and products such as lathes, turbine blades, clock gears, and large 3D printed components. The manufacturing of these joints have largely been done by CNC milling machines that use specialized tools. The objective of this study was to determine the optimal machine parameters to produce a dovetail joint in Aluminum 7075-T6 plate with the highest accuracy as possible using a WEDM process. The experimental results were analyzed through ANOVA and the optimal results were presented. Further work is also discussed to incorporate the manufacturing time into the model.
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    Resource efficient process chain development of a modular CubeSat spaceframe
    (Elsevier, 2019) Oberholzer, J. F.; Uheida, E. H.; Oosthuizen, G. A.
    ENGLISH ABSTRACT: A CubeSat is a 10×10×10 cm cube that can weigh up to 1.33 kg. This design offers a less expensive alternative for space enthusiasts to explore the cosmos, even though the total weight is very limited. For a CubeSat to be allowed to launch, it must adhere to certain specifications outlined in the CubeSat Design Specifications document. This places several restrictions on the satellite in terms of weight, size and center of gravity, and innovative solutions need to be explored during integration to meet these specifications. Having a spaceframe that can easily be assembled and disassembled will help smooth out the integration stage and save a significant time that can then be allocated elsewhere in the developmental stages. The increasing relevance of resource efficient manufacturing is prevalent through the continually rising costs of resources and energy. In order to stay competitive, manufacturers must develop resource efficient process chains to gain an advantage in the market. This study focused on developing a resource efficient process chain to manufacture a modular CubeSat spaceframe. This spaceframe must adhere to the CubeSat Design specifications, as well as meet the customer’s needs. A unique assembly process was designed that eliminated the need for screws structure together. Instead the spaceframe relies on interference fits, and utilizes the unique deployment method of the Poly-Picosatellite Orbital Deployer to ensure that the assembly does not fail. A material selection procedure was utilized, along with resource efficient manufacturing process chains to develop a CubeSat structure that is very cost effective to produce, easily assembled and disassembled and weighed less than most of the market leading CubeSat structures.
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    Strategies to standardise bamboo for manufacturing process chains
    (Elsevier, 2017) Burger, M. D.; Oosthuizen, G. A.; Oberholzer, J. F.; De Wet, P.; Ras, C. I.
    The manufacturing challenges industry face need to be addressed in the multifaceted context of sustainability. In order to stay relevant and competitive the manufacturing industry is investigating several types of sustainable hybrid materials for structural components. Bamboo is a versatile plant with thousands of applications, but is produced in various shapes and sizes with different mechanical characteristics. Therefore, the objective of this study is to investigate strategies to standardise bamboo for manufacturing process chains. The treatments that bamboo must undergo in order to be used in high quality and resilient products were investigated. Sustainable and environmental friendly approaches to deal with pests and different drying methods of bamboo are discussed. Factors to be standardized are identified and strategies to standardize this in each phase before the manufacturing process chains are elaborated on. Benchmarking is done on the diameter and wall-thickness of the different tubes and an allowable variance is identified for each tube.
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    Sustainably manufacturing a bamboo bicycle in a container factory
    (Elsevier, 2017) De Wet, P.; Oosthuizen, G. A.; Burger, M. D.; Oberholzer, J. F.
    In order for manufacturing suppliers to stay competitive in the global market, innovative and resource efficient process chains need to be a part of the manufacturing strategy. Secondary manufacturing process steps entail the assembly and surface treatment manufacturing steps, after the primary cutting and shaping of the components. Bicycles have an enormous effect on society, both in terms of socio-economics and of advancing modern industrial processes. In order to manufacture bamboo bicycle frames in South Africa, innovative designs and process chains need to be developed. Container factories could be the answer to reduce costs and increase resource efficiency. In this study, the feasibility of manufacturing bamboo bicycle in shipping containers is investigated. These results are then used to evaluate the sustainability of manufacturing bamboo bicycles in container factories.