Design and Development of 3-Axis Benchtop CNC Milling Machine for Educational Purpose

The main factor in improving learning skills is providing students with hands-on laboratory experience, and the small-scale machine can accomplish academic programs requiring students to learn machining skills. This paper aims to design and develop a 3-axis CNC milling machine with a PC-based open architecture controller in a vertical position open frame structure. Some technical specifications were randomly selected based on the capabilities of similarly sized machines reviewed in previous work. The designed machine consisted of inexpensive off-the-shelf hardware components capable of machining the sample block with high cutting speed and reasonable precision. The accepted percentage error of circular and straightness test readings is below the set requirements. This machine is not intended for series production and precise machining. It can still effectively replace the high cost of commercial CNC machines and be used in any higher education institution offering technical courses

Design and Development of 3-Axis Benchtop CNC Milling Machine for Educational Purpose

The main factor in improving learning skills is providing students with hands-on laboratory experience, and the small-scale machine can accomplish academic programs requiring students to learn machining skills. This paper aims to design and develop a 3-axis CNC milling machine with a PC-based open architecture controller in a vertical position open frame structure. Some technical specifications were randomly selected based on the capabilities of similarly sized machines reviewed in previous work. The designed machine consisted of inexpensive off-the-shelf hardware components capable of machining the sample block with high cutting speed and reasonable precision. The accepted percentage error of circular and straightness test readings is below the set requirements. This machine is not intended for series production and precise machining. It can still effectively replace the high cost of commercial CNC machines and be used in any higher education institution offering technical courses

An integrated framework for developing generic modular reconfigurable platforms for micro manufacturing and its implementation

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The continuing trends of miniaturisation, mass customisation, globalisation and wide use of the Internet have great impacts upon manufacturing in the 21st century. Micro manufacturing will play an increasingly important role in bridging the gap between the traditional precision manufacturing and the emerging technologies like MEMS/NEMS. The key requirements for micro manufacturing in this context are hybrid manufacturing capability, modularity, reconfigurability, adaptability and energy/resource efficiency. The existing design approaches tend to have narrow scope and are largely limited to individual manufacturing processes and applications. The above requirements demand a fundamentally new approach to the future applications of micro manufacturing so as to obtain producibility, predictability and productivity covering the full process chains and value chains. A novel generic modular reconfigurable platform (GMRP) is proposed in such a context. The proposed GMRP is able to offer hybrid manufacturing capabilities, modularity, reconfigurablity and adaptivity as both an individual machine tool and a micro manufacturing system, and provides a cost effective solution to high value micro manufacturing in an agile, responsive and mass customisation manner. An integrated framework has been developed to assist the design of GMRPs due to their complexity. The framework incorporates theoretical GMRP model, design support system and extension interfaces. The GMRP model covers various relevant micro manufacturing processes and machine tool elements. The design support system includes a user-friendly interface, a design engine for design process and design evaluation, together with scalable design knowledge base and database. The functionalities of the framework can also be extended through the design support system interface, the GMRP interface and the application interface, i.e. linking to external hardware and/or software modules. The design support system provides a number of tools for the analysis and evaluation of the design solutions. The kinematic simulation of machine tools can be performed using the Virtual Reality toolbox in Matlab. A module has also been developed for the multiscale modelling, simulation and results analysis in Matlab. A number of different cutting parameters can be studied and the machining performance can be subsequently evaluated using this module. The mathematical models for a non-traditional micro manufacturing process, micro EDM, have been developed with the simulation performed using FEA. Various design theories and methodologies have been studied, and the axiomatic design theory has been selected because of its great power and simplicity. It has been applied in the conceptual design of GMRP and its design support system. The implementation of the design support system is carried out using Matlab, Java and XML technologies. The proposed GMRP and framework have been evaluated through case studies and experimental results

Digital fabrication inspired design: Influence of fabrication parameters on a design process

The relation between architecture and building technologies has played a vital role in the development of both disciplines throughout the history. The link between the two is also valid in the present times, as the design and production processes are influenced by computational advances. Considering the use of a particular digital fabrication method, this research intends to look into the design-production relation and attempts to answer the question of how the manufacturing parameters can be integrated into the design process to facilitate the design-to-production communication. It is argued that the above is achievable through the application of a simulation-based algorithmic procedures derived from the inherent logic of a fabrication machine's functionality. The above stated was studied through creation of two custom tools facilitating the design process – namely a library for the Processing programming language and a bespoke design procedure - both based on a functionality of the CNC milling machines. Finally, the conclusion is made that broader implementation of custom design procedures with underlying digital fabrication logic has a potential of altering the design process and facilitate the design-to-factory communication

Acquisition and reconstruction of 3D objects for robotic machining

With the evolution of the techniques of acquisition of Three-Dimensional (3D) image it became possible to apply these in more and more areas, as well as to be used for research and hobbyists due to the appearance of low cost 3D scanners. Among the application of 3D acquisitions is the reconstruction of objects, which allows for example to redo or remodel an existing object that is no longer on the market. Another rise tech is industrial robot, that is highly present in the industry and can perform several tasks, even machining activities, and can be applied in more than one type of operation. The purpose of this work is to acquire a 3D scene with low-cost scanners and use this acquisition to create the tool path for roughing a workpiece, using an industrial robot for this machining task. For the acquisition, the Skanect software was used, which had satisfactory results for the work, and the exported file of the acquisition was worked on the MeshLab and Meshmixer software, which were used to obtain only the interest part for the milling process. With the defined work object, it was applied in Computer Aided Manufacturing (CAM) software, Fusion 360, to generate the tool path for thinning in G-code, which was converted by the RoboDK software to robot code, and this also allowed to make simulation of the machining with the desired robot. With the simulation taking place as expected, it was implemented in practice, performing the 3D acquisition machining, thus being able to verify the machining technique used. Furthermore, with the results of acquire, generation of toolpath and machining, was possible to validate the proposed solution and reach a conclusion of possible improvements for this project.Com a evolução das técnicas de aquisição de imagem 3D tornou-se possível aplicá-las em cada vez mais áreas, bem como serem utilizadas por pesquisadores e amadores devido ao surgimento de scanners 3D de baixo custo. Entre as aplicações de aquisições 3D está a reconstrução de objetos, o que permite, por exemplo, refazer ou remodelar um objeto existente que não está mais no mercado. Outra tecnologia em ascensão é o robô industrial, que está muito presente na indústria e pode realizar diversas tarefas, até mesmo atividades de fabrico, e ser aplicado em mais de um tipo de operação. O objetivo deste trabalho é adquirir uma cena 3D com scanners de baixo custo e utilizar esta aquisição para criar o caminho da ferramenta para o desbaste de uma peça, utilizando um robô industrial nesta tarefa de usinagem. Para a aquisição foi utilizado o software Skanect, que obteve resultados satisfatórios para o trabalho, e o arquivo exportado da aquisição foi trabalhado nos softwares MeshLab e Meshmixer, os quais foram utilizados para obter apenas a parte de interesse para o processo de fresagem. Com o objeto de trabalho defino, este foi aplicado em software CAM, Fusion 360, para gerar o caminho de ferramentas para o desbaste em G-code, o qual foi convertido pelo Software RoboDK para código de rôbo, e este também permitiu fazer simulação da maquinação com o rôbo pretendido. Com a simulação ocorrendo de acordo com o esperado, esta foi implementada em prática, realizando a maquinação da aquisição 3D, assim podendo verificar a técnica de maquinação utilizada. Além disso com os resultados de aquisição, geração de toolpath e maquinação, foi possível validar a solução proposta e chegar a uma conclusão de possíveis melhorias para este projeto

Surface Location Error in Robotic Milling: Modeling and Experiments

Robotic milling offers new opportunities for discrete part manufacturing as an alternative to milling using large conventional machine tools. The advantage of industrial robots is their large work volume, configurability, and comparatively low cost. However, robots are significantly less stiff than conventional machine tools, which can lead to poor surface finish, low machining accuracy, and low material removal rates. The purpose of this research is to predict the geometric errors, or surface location errors, that occur in a robotic mulling tool path, validate these predictions with machining tests, and compensate these errors by tool path modification. Compared with conventional machine tools, robots possess low stiffness, low frequency vibration modes and the presence of these modes causes surface location errors that are nearly independent of spindle speed in the range typically used for machining. Additionally, the robot often exhibits errors relative to the commanded tool path. By developing an understanding of both the dynamics of the robot and its tool path accuracy, predictions were made of the surface location error for a machined part and a compensation algorithm was developed. The accuracy of the predictions and compensation algorithm were verified with a series of experiments. Through this research it was determined that robotic milling is prone to large surface location errors, but it is possible to reduce these through offline compensation

From recycled machining waste to useful powders: sustainable fabrication and utilization of feedstock powder for metal additive manufacturing

2018 Summer.Includes bibliographical references.Gas atomized (GA) powders are the most common feedstock for state-of-the-art metal additive manufacturing (AM) technologies because of their spherical morphology and controllable particle size distribution. However, significant resource consumption, e.g., energy and inert gas, are required to produce GA powders, leading to high costs and limited availability in alloy compositions. To fulfill the growing demand for alternative and sustainable feedstock production for metal AM, my research aimed to explore a mechanical milling strategy to fabricate 304L stainless steel powders from recycled machining waste chips. A theoretical analysis was performed to evaluate the impact force on powder and the consequent maximum deformation depth per impact during ball milling with different ball diameters. The modeling results suggest that 20-mm-diameter balls effectively reduce the powder particle size while 6-mm-diameter balls are favorable in terms of forming spherical morphology of the powder. Various ball milling procedures were implemented to experimentally investigate the effect of ball diameter on the powder morphology evolution and particle size refinement. It is found that a novel dual-stage ball milling strategy effectively converts machining chips to powder with desirable characteristics (near spherical morphology with particle sizes of 38-150 μm) for metal additive manufacturing. The ball milled powders created from the machining chips also exhibit a higher hardness than GA powder, based on nanoindentation testing. To verify the viability of using the ball milled powder created from machining chips in metal AM, single tracks (ST) have been successfully deposited via laser engineered net shaping (LENS®) and compared to the single tracks made from GA powder (ST-GA) using identical deposition conditions. The microstructures of these single tracks exhibited adequate adhesion to the substrate, a uniform melt pool geometry, continuity, and minimal splatter. Minimal differences in grain structure were observed between the single tracks made from ball milled powder (ST-BM) and ST-GA. However, the average nanoindentation hardness of ST-BM is approximately 21% higher than that of ST-GA. Although the chemical compositions of both types of single tracks are within the compositional range of a 304L stainless steel, the increase in hardness of ST-BM is attributed to a 1.7 wt.% decrease in Ni content, potentially leading to an increase in the amount of martensite. Therefore, my research has discovered a sustainable approach to fabricate powders from recycled machining chips and has proved it is feasible to utilize these powders as feedstock in metal AM. Future work on depositing bulk samples with more complex geometry using the ball milled powder is proposed

Electric Vehicle Battery Module Dismantling "Analysis and Evaluation of Robotic Dismantling Techniques for Irre- versible Fasteners, including Object Detection of Components."

This thesis examines a study of The Litium-Ion Battery (LIB) from a electric vehicle, and it’s recycling processes. A Battery Module (BM) from the LIB is shredded when considered an End-Of-Life product, and motivates for automated dismantling concepts to separate the components to save raw materials. From State-of-the-art (SoA) research projects and background theory, automatic module dis- mantling concepts have been evaluated for a Volkswagen E-Golf 2019 battery module. The presence of irreversible fasteners make the use off destructive dismantling techniques neces- sary. This study evaluates two different concepts to disconnect laser welds holding together the compressive plates made of steel. A hydraulic actuated concept is first investigated to separate the welded compressive plates within the casing. A FEM analysis with different configurations is performed to evaluate the most effective hydraulic solution when analysing the Von Mises stress. This solution is further compared with another automatic dismantling concept, namely milling. For the purpose of an automated milling concept, manipulators from ABB are assessed and the feasibility is verified based on results from manual milling operation. The proposed dismantling operation is made possible by developing a system architecture combining robotic control and computer vision. Open source software based on Robot Op- erating System (ROS) and MoveIt connect and control an ABB IRB4400 industrial robot whereas the computer vision setup involves a cutting edge 3D camera, Zivid, and object detection algorithm YOLOv5 best suited for this task. Adjustable acquisition settings in services from Zivid’s ROS driver are tested to accomplish the optimal capture configuration. Two datasets generated with RoboFlow were exported in the YOLOv5 PyTorch format. Custom object detection models with annotated components from the BM was trained and tested with image captures. All in all, this study demonstrates that the automatic dismantling of battery modules can be achieved even though they include irreversible fasteners. The proposed methods are verified on a specific battery module (Egolf 2019) but are flexible enough to be easily extended to a large variety of EV battery modules