Computer-aided Tooling Design for Manufacturing Processes

Tooling design for manufacturing processes refers to direct tooling for making a part such as molds and dies for injection molded parts and metal stampings, or for supporting machining operations such as jigs and fixtures. This paper summarizes some of the R&D activities in those areas over a period of 20 years in the Department of Mechanical Engineering, National University of Singapore. It is notable that increasing use of computer tools has turned what is used to be known as a “black art” into a discipline embracing both heuristic and scientific analyses.Singapore-MIT Alliance (SMA

Latest Developments in Industrial Hybrid Machine Tools that Combine Additive and Subtractive Operations

Hybrid machine tools combining additive and subtractive processes have arisen as a solution to increasing manufacture requirements, boosting the potentials of both technologies, while compensating and minimizing their limitations. Nevertheless, the idea of hybrid machines is relatively new and there is a notable lack of knowledge about the implications arisen from their in-practice use. Therefore, the main goal of the present paper is to fill the existing gap, giving an insight into the current advancements and pending tasks of hybrid machines both from an academic and industrial perspective. To that end, the technical-economical potentials and challenges emerging from their use are identified and critically discussed. In addition, the current situation and future perspectives of hybrid machines from the point of view of process planning, monitoring, and inspection are analyzed. On the one hand, it is found that hybrid machines enable a more efficient use of the resources available, as well as the production of previously unattainable complex parts. On the other hand, it is concluded that there are still some technological challenges derived from the interaction of additive and subtractive processes to be overcome (e.g., process planning, decision planning, use of cutting fluids, and need for a post-processing) before a full implantation of hybrid machines is fulfilledSpecial thanks are addressed to the Industry and Competitiveness Spanish Ministry for the support on the DPI2016-79889-R INTEGRADDI project and to the PARADDISE project H2020-IND-CE-2016-17/H2020-FOF-2016 of the European Union's Horizon 2020 research and innovation program

An intelligent knowledge based cost modelling system for innovative product development

This research work aims to develop an intelligent knowledge-based system for product cost modelling and design for automation at an early design stage of the product development cycle, that would enable designers/manufacturing planners to make more accurate estimates of the product cost. Consequently, a quicker response to customers’ expectations. The main objectives of the research are to: (1) develop a prototype system that assists an inexperienced designer to estimate the manufacturing cost of the product, (2) advise designers on how to eliminate design and manufacturing related conflicts that may arise during the product development process, (3) recommend the most economic assembly technique for the product in order to consider this technique during the design process and provide design improvement suggestions to simplify the assembly operations (i.e. to provide an opportunity for designers to design for assembly (DFA)), (4) apply a fuzzy logic approach to certain cases, and (5) evaluate the developed prototype system through five case studies. The developed system for cost modelling comprises of a CAD solid modelling system, a material selection module, knowledge-based system (KBS), process optimisation module, design for assembly module, cost estimation technique module, and a user interface. In addition, the system encompasses two types of databases, permanent (static) and temporary (dynamic). These databases are categorised into five separate groups of database, Feature database, Material database, Machinability database, Machine database, and Mould database. The system development process has passed through four major steps: firstly, constructing the knowledge-based and process optimisation system, secondly developing a design for assembly module. Thirdly, integrating the KBS with both material selection database and a CAD system. Finally, developing and implementing a ii fuzzy logic approach to generate reliable estimation of cost and to handle the uncertainty in cost estimation model that cannot be addressed by traditional analytical methods. The developed system has, besides estimating the total cost of a product, the capability to: (1) select a material as well as the machining processes, their sequence and machining parameters based on a set of design and production parameters that the user provides to the system, and (2) recommend the most economic assembly technique for a product and provide design improvement suggestion, in the early stages of the design process, based on a design feasibility technique. It provides recommendations when a design cannot be manufactured with the available manufacturing resources and capabilities. In addition, a feature-by-feature cost estimation report was generated using the system to highlight the features of high manufacturing cost. The system can be applied without the need for detailed design information, so that it can be implemented at an early design stage and consequently cost redesign, and longer lead-time can be avoided. One of the tangible advantages of this system is that it warns users of features that are costly and difficult to manufacture. In addition, the system is developed in such a way that, users can modify the product design at any stage of the design processes. This research dealt with cost modelling of both machined components and injection moulded components. The developed cost effective design environment was evaluated on real products, including a scientific calculator, a telephone handset, and two machined components. Conclusions drawn from the system indicated that the developed prototype system could help companies reducing product cost and lead time by estimating the total product cost throughout the entire product development cycle including assembly cost. Case studies demonstrated that designing a product using the developed system is more cost effective than using traditional systems. The cost estimated for a number of products used in the case studies was almost 10 to 15% less than cost estimated by the traditional system since the latter does not take into consideration process optimisation, design alternatives, nor design for assembly issue

Development of a windows based computer-aided die design system for die casting

Master'sMASTER OF ENGINEERIN

Continuous improvement of a machining process by designing a new jig

This thesis report gives an insight on how an often overlooked, jig and fixture used as a manufacturing aid to produce a product and essential for delivering products reliably and repeatedly with high quality. This continuous improvement project of an exciting machining process of winding cones used overhead garage doors. The improvement was a necessity with a forecast for 2019 estimating the need for 43% faster production cycle (takt time) compared to the previous year. Hence, the main objective was to reduce the machining time required per part by designing a modular jig system, ideally with 12 parts per cycle. To make the work in an organized structure the project was dived into four phases namely: research, design, machining and implementation. The research phase included in the study of the old jig in use, analysing the process and sketching the basic requirements. The design phase was based on the methodology of Design for Six Sigma methodology for the fixture. Different kind of jig components was designed and assembled using SOLIDWORKS CAD model. The critical review of design iteration was analysed using SWO analysis (short version of the standard SWOT analysis) for design. The machining of most components of the jig was done in-house with tacit knowledge of the machinist instead of using CAM software’s making it first of its kind project in developing knowledge management in the company for future jig requirements. The critical outcomes of the project were harvested from the implementation phase. The newly machined modular jig system proved to have increased the number of parts machined per day by 32% with expected savings of more than €6000 per annum. The added benefit of a modular jig system was that one base (skeleton of the jig) could be used in machining different products. Also, future projects now have the intellectual and physical resources of making jigs and fixtures in-house. This drastically reduces the lead times for new parts, which is crucial for a small-medium enterprise stay competitive.Este relatório dá uma visão sobre como um acessório usado pode auxiliar na produção de forma a produzir um produto e os elementos essenciais para a sua entrega de forma confiável e repetida com alta qualidade. Este é um projeto de melhoria contínua de um processo de maquinagem de cones de enrolamento, usados em portas de garagem suspensas. A melhoria surjiu de uma necessidade com a previsão para 2019, estimando a necessidade de um ciclo de produção 43% mais rápido (takt time) em comparação com o ano anterior. Assim, o objetivo principal passava por reduzir o tempo de maquinagem necessário por peça, projetando um sistema de gabarit modular, idealmente com 12 partes por ciclo. Para realizar o trabalho numa estrutura organizada, o projeto foi dividido em quatro fases: pesquisa, projeto, maquinagem e implementação. As fases de pesquisa foram incluídas no estudo do antigo gabarit em uso, analisando o processo e esboçando os requisitos básicos. A fase de projeto foi baseada na metodologia de Design for Six Sigma para um dispositivo. Foram projetados e montados diferentes tipos de componentes de gabarit usando o modelo SOLIDWORKS CAD. A revisão crítica da iteração do projeto foi analisada usando a análise SWO (versão reduzida da análise SWOT convencional) para projeto. A maquinagem da maioria dos componentes do gabarit foi feita internamente com conhecimento tácito do responsável técnico, recorrendo ao software CAM, tornando-o o primeiro de seu tipo no desenvolvimento da gestão do conhecimento na empresa para futuros requisitos de gabarit. Os principais resultados e conclusões dos projetos foram descritos na fase de implementação. O sistema de gabarit modular recém-maquinado provou ter aumentado o número de peças maquinadas por hora em 32%, com economias comprovadas de mais de € 6.000 por ano. O benefício adicional de um sistema de gabarit modular consiste de criar uma base (esqueleto do gabarit) usada na maquinagem de diferentes produtos, e projetos futuros, permitindo à empresa deter os recursos intelectuais e físicos de criar gabarits e acessórios internos. Assim, foi reduzido drasticamente o tempo de espera para novas peças, o que é crucial para uma pequena média empresa permanecer competitiva

Process assessment for the extended enterprise during early product development using novel computational techniques

Manufacturing practices have evolved over the last quarter of a century in the light of changes to manufacturing technology and demand. To sustain this growth companies are increasingly focused on better design and quicker time to market, to stay one step ahead of the competition. Expanding technology capabilities have included microcomputers and telecommunications. In particular the Internet has allowed businesses to trade with an extended customer base, resulting in a greater demand and perpetuating the cycle. To mirror this statement, businesses are looking increasingly far and wide for suitable suppliers. This work identifies a need in the market for an Internet based supplier selection function, during early product development. The development of this work differs significantly from other process selection methods by the use of the Internet to link companies. It has advantages for product development relating to the scope of the opportunities, diversity of possible manufacturing operations and rapid assessment of processes. In particular the system can be broken down into two main functions. Process Selection (PS) and Factory Selection (FS). The PS method presented enables many processes to be modelled, in multiple organisations for a single product. The Internet is used to gain access to supplier facilities by adopting the same principles as on-line banking, or shopping, for data input and access. The results of these assessments are retained by the system for later analysis. The FS method utilises this data to model and compare supplier attributes, allowing the user to manipulate the data to fit their requirements. Testing of the system has proved encouraging for many operations, including Injection Moulding and CNC Machining. It can be concluded that the identification of manufacturing operations outside the remit of companies' normal scope will create further opportunities for supplier integration

Survey on Additive Manufacturing, Cloud 3D Printing and Services

Cloud Manufacturing (CM) is the concept of using manufacturing resources in a service oriented way over the Internet. Recent developments in Additive Manufacturing (AM) are making it possible to utilise resources ad-hoc as replacement for traditional manufacturing resources in case of spontaneous problems in the established manufacturing processes. In order to be of use in these scenarios the AM resources must adhere to a strict principle of transparency and service composition in adherence to the Cloud Computing (CC) paradigm. With this review we provide an overview over CM, AM and relevant domains as well as present the historical development of scientific research in these fields, starting from 2002. Part of this work is also a meta-review on the domain to further detail its development and structure

Collaboration strategies and technological innovation : a contractual perspective of the relationship between firms and techonological centers

In this paper, a theoretical framework for analyzing the selection of governance structures for implementing collaboration agreements between firms and Technological Centers is presented and empirically discussed. This framework includes Transaction Costs and Property Rights' theoretical assumptions, though complemented with several proposals coming from the Transactional Value Theory. This last theory is used for adding some dynamism in the governance structure selection. As empirical evidence of this theoretical explanation, we analyse four real experiences of collaboration between firms and one Technological Center. These experiences are aimed to represent the typology of relationships which Technological Centers usually face. Among others, a key interesting result is obtained: R&D collaboration activities do not need to always be organized through hierarchical solutions. In those cases where future expected benefits and/or reputation issues could play an important role, the traditional more static theories could not fully explain the selected governance structure for managing the R&D relationship. As a consequence, these results justify further research about the adequacy of the theoretical framework presented in this paper in other contexts, for example, R&D collaborations between firms and/or between Universities or Public Research Centers and firms