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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

MDI data preparation for numerically controlled milling machines

De Queiroz, Abelardo Alves January 1983 (has links)
The work reported in this thesis is concerned with both a fundamental assessment and the provision of a comprehensive MDI system for milling machines. The conceptual design has led to the realisation of a prototype work station which represents advances beyond the current state of the art for systems containing an APT-like processor and employs a powerful and flexible conversationally-based system with graphics support. The work station has been interfaced in STR mode to a numerically controlled milling machine and the effectiveness of the programming system has been demonstrated by the production of four workpieces.
2

NC řízení frézky na platformě Beckhoff / NC control system on Beckhoff platform

Jelínek, Pavel January 2017 (has links)
This thesis deals with a creation of a control system of 3-axis milling machine. The beginning of the thesis is dedicated to the general description of the problematic of the numerically controlled machines and the technologies used in this branch. The next chapter describes mechanical and electronical adjustments of the machine. Following chapters are dedicated to the creation of PLC program and HMI using the TwinCAT software. In conclusion, this thesis deals with commissioning of the machine, measuring its geometrical accuracy and testing.
3

Konstrukce malé CNC frézky / Design of small CNC milling machine

Jagoš, Roman January 2012 (has links)
This master´s thesis deals with design of small CNC milling machines and comparing CNC tabletop milling machines in the world market. It is also done design of small CNC milling machine through the use of contemporary and modern trends, used in design of machine tools.
4

Konstrukční návrh malé modelářské CNC frézky / Design of small hobby CNC milling machine

Večeř, Petr January 2016 (has links)
This thesis deals with the structural design of small model CNC milling machines. The work includes research modeller CNC milling machines available primarily on the Czech market, on whose basis are then selected the appropriate parameters for machine design. The thesis contains further structural calculations, selection of appropriate components, production drawings and 3D model that shows the final solution of constructed facility.
5

Modernizace řízení frézky FNG / The modernization of control system of milling machine FNG

Holas, Jiří January 2021 (has links)
This thesis deals with a proposal modernisation of control and electroinstalation of the milling machine FNG 32. The thesis is divided into several sections: The first section is dedicated to the research of the milling machine and the description of its current condition. The second section deals with possible options of retrofitting and with the components.The third section includes the technical and economical evaluation and the selection of the solution. In the next section, the selected components are described and an electronic documentation of the machine has been created in EPLAN. In the last section, a proposal of control of the milling machine has been created with the help of the TwinCAT development environment provided by Beckhoff company.
6

Avaliação do erro estático da ferramenta de uma máquina fresadora com arquitetura paralela. / An experimental test-bed to evaluate the tool positioning error in a redundant parallel robot for milling applications.

Auza Tarquino, Brian Juan 27 April 2016 (has links)
Os mecanismos amplamente utilizados em aplicações industriais são de tipo serial, porém há algum tempo vem sendo desenvolvidos estudos sobre as vantagens que os mecanismos de arquitetura paralela oferecem em contraposição com os seriais. Rigidez, precisão, altas frequências naturais e velocidade são algumas características que os mecanismos paralelos atribuem a máquinas já consolidadas na indústria, destinadas principalmente nas operações de manipulação (pick and place). Nesse sentido, é relevante o estudo sobre a funcionalidade em outros tipos de operação como a usinagem e, particularmente o fresamento. Para isto, devem-se ainda explorar e desenvolver as capacidades dos mecanismos paralelos em relação à rigidez e à precisão nas operações mencionadas. Foi desenvolvido previamente o projeto e montagem do protótipo de uma máquina fresadora de arquitetura paralela. Também aracterizado pela redundância na atuação para o posicionamento da ferramenta. Com este intuito, pretende-se no trabalho atual, avaliar o erro estático de posicionamento da ferramenta por métodos experimentais, quantificar os deslocamentos, realizar um mapeamento experimental em diversas configurações dos membros. Por outro lado, pretende-se adaptar um modelo numérico simplificado que possa prever as deformações elásticas em diversas configurações, que contemple o efeito de juntas lineares flexíveis e que de alguma forma ajude a identificar as principais fontes de erro. Para tal, foram elaboradas rotinas de programação que através da cinemática inversa e o uso do método dos elementos finitos tentem prever o que de fato acontece nos experimentos. Foi proposta também uma implementação alternativa para o controle do mecanismo através de um software CNC e a conversão de coordenadas cartesianas em coordenadas dos atuadores, isto ajudaria na geração do código G. Finalmente, foram elaboradas algumas trajetórias que tentam avaliar a exatidão e repetitividade do mecanismo além de descrever outras trajetórias livres. / Serial mechanisms have been widely used in industrial applications, on the other hand some studies related to advantages of parallel kinematics and its benefits have been developed in the last decades. Stiffness, accuracy, high natural frequencies and velocities are some characteristics that this kind of kinematic architecture attribute to some industrial machines specially used in \"pick and place\" operations. However, it remains relevant to study the functionality that parallel mechanisms could offer in other kind of applications such as milling. In order to achieve this, it is important to evaluate and explore the capabilities and performance characteristics when precision and stiffness are involved. A milling machine with parallel architecture prototype has been designed and constructed in previous works. The tool positioning is characterized by redundant actuation. The present work aims to evaluate the static error of the tool positioning mechanism by experimental procedures, in order to quantify the tool displacements under some established loads and to elaborate an experimental map for static error in different mechanism configurations. On the other hand, it is intended to adapt a simplified numerical model that could predict the stiffness behavior along the workspace including the effect of flexible linear actuators. For this purpose, a finite element method script was developed to solve all the structure displacements. In addition, it was proposed an alternative control implementation that works through an open source CNC software and its appropriate kinematic conversion for the mechanism characteristics and the generation of G Code scripts. Finally, some trajectories were planned in order to evaluate accuracy and repeatability in two proposed paths besides some other free operations.
7

Design, Analysis, and Prototyping of A 3×PPRS Parallel Kinematic Mechanism for meso-Milling

Zhao, Guan Lei 11 December 2013 (has links)
Parallel Kinematic Mechanisms (PKMs) are well suited for high-accuracy applications such as meso-milling. However, drawbacks such as limited platform tilting angle and high configuration dependency of stiffness often limit their usage. In this Thesis, a new six degree-of-freedom (dof) PKM architecture based on a 3×PPRS topology is proposed, in order to address these problems. The new PKM is presented, and its inverse kinematics and Jocobian matrix are derived. The kinematic relations are incorporated into MATLAB to calculate the workspace of the PKM. The stiffness of the new PKM is obtained using Finite Element Analysis (FEA), and configuration dependency of stiffness is investigated. The proposed new mechanism is compared with three similar existing 6-dof PKMs, and it is shown that the new PKM exhibits higher stiffness. Lastly, three meso-Milling Machine Tool prototypes were designed and built. In particular, Prototype III is based on the new mechanism.
8

Design, Analysis, and Prototyping of A 3×PPRS Parallel Kinematic Mechanism for meso-Milling

Zhao, Guan Lei 11 December 2013 (has links)
Parallel Kinematic Mechanisms (PKMs) are well suited for high-accuracy applications such as meso-milling. However, drawbacks such as limited platform tilting angle and high configuration dependency of stiffness often limit their usage. In this Thesis, a new six degree-of-freedom (dof) PKM architecture based on a 3×PPRS topology is proposed, in order to address these problems. The new PKM is presented, and its inverse kinematics and Jocobian matrix are derived. The kinematic relations are incorporated into MATLAB to calculate the workspace of the PKM. The stiffness of the new PKM is obtained using Finite Element Analysis (FEA), and configuration dependency of stiffness is investigated. The proposed new mechanism is compared with three similar existing 6-dof PKMs, and it is shown that the new PKM exhibits higher stiffness. Lastly, three meso-Milling Machine Tool prototypes were designed and built. In particular, Prototype III is based on the new mechanism.
9

Avaliação do erro estático da ferramenta de uma máquina fresadora com arquitetura paralela. / An experimental test-bed to evaluate the tool positioning error in a redundant parallel robot for milling applications.

Brian Juan Auza Tarquino 27 April 2016 (has links)
Os mecanismos amplamente utilizados em aplicações industriais são de tipo serial, porém há algum tempo vem sendo desenvolvidos estudos sobre as vantagens que os mecanismos de arquitetura paralela oferecem em contraposição com os seriais. Rigidez, precisão, altas frequências naturais e velocidade são algumas características que os mecanismos paralelos atribuem a máquinas já consolidadas na indústria, destinadas principalmente nas operações de manipulação (pick and place). Nesse sentido, é relevante o estudo sobre a funcionalidade em outros tipos de operação como a usinagem e, particularmente o fresamento. Para isto, devem-se ainda explorar e desenvolver as capacidades dos mecanismos paralelos em relação à rigidez e à precisão nas operações mencionadas. Foi desenvolvido previamente o projeto e montagem do protótipo de uma máquina fresadora de arquitetura paralela. Também aracterizado pela redundância na atuação para o posicionamento da ferramenta. Com este intuito, pretende-se no trabalho atual, avaliar o erro estático de posicionamento da ferramenta por métodos experimentais, quantificar os deslocamentos, realizar um mapeamento experimental em diversas configurações dos membros. Por outro lado, pretende-se adaptar um modelo numérico simplificado que possa prever as deformações elásticas em diversas configurações, que contemple o efeito de juntas lineares flexíveis e que de alguma forma ajude a identificar as principais fontes de erro. Para tal, foram elaboradas rotinas de programação que através da cinemática inversa e o uso do método dos elementos finitos tentem prever o que de fato acontece nos experimentos. Foi proposta também uma implementação alternativa para o controle do mecanismo através de um software CNC e a conversão de coordenadas cartesianas em coordenadas dos atuadores, isto ajudaria na geração do código G. Finalmente, foram elaboradas algumas trajetórias que tentam avaliar a exatidão e repetitividade do mecanismo além de descrever outras trajetórias livres. / Serial mechanisms have been widely used in industrial applications, on the other hand some studies related to advantages of parallel kinematics and its benefits have been developed in the last decades. Stiffness, accuracy, high natural frequencies and velocities are some characteristics that this kind of kinematic architecture attribute to some industrial machines specially used in \"pick and place\" operations. However, it remains relevant to study the functionality that parallel mechanisms could offer in other kind of applications such as milling. In order to achieve this, it is important to evaluate and explore the capabilities and performance characteristics when precision and stiffness are involved. A milling machine with parallel architecture prototype has been designed and constructed in previous works. The tool positioning is characterized by redundant actuation. The present work aims to evaluate the static error of the tool positioning mechanism by experimental procedures, in order to quantify the tool displacements under some established loads and to elaborate an experimental map for static error in different mechanism configurations. On the other hand, it is intended to adapt a simplified numerical model that could predict the stiffness behavior along the workspace including the effect of flexible linear actuators. For this purpose, a finite element method script was developed to solve all the structure displacements. In addition, it was proposed an alternative control implementation that works through an open source CNC software and its appropriate kinematic conversion for the mechanism characteristics and the generation of G Code scripts. Finally, some trajectories were planned in order to evaluate accuracy and repeatability in two proposed paths besides some other free operations.
10

Návrh malé modelářské CNC frézky s pevným stolem / Design of small hobby CNC milling machine with fixed table

Hanzal, Jiří January 2020 (has links)
The topic of this work is the design of a small model CNC milling machine with a fixed table for machining wood, plastic, or light alloys (Al, Zn, etc.). It also includes a calculation report and drawing documentation of selected nodes. The beginning of this work consists of an introduction to the issue of milling machines, their distribution and subsequent market analysis. Subsequently, the input parameters are designed on the basis of market analysis and in the last part there is a calculation report, the design of the milling machine itself and a short economic evaluation.

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