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Additive manufacturing of spatial trusses from polymeric materials
Křivohlavý, Petr ; Němeček, Stanislav (referee) ; Škaroupka, David (advisor)
This thesis is focused on creating polymer lattice struts without any necessary support in full length using robotic 3D printing. The aim of the thesis is to find suitable process parameters and printing strategies with respect to the accuracy of the polymer struts. A statistical model of effects of individual process parameters has been produced to achieve stated objectives. The model enables finding optimal process parameters. The printing strategies for thus established process parameters are tested to increase the accuracy of the finished print and the quality of the bonds between individual struts. The accuracy assessment is executed using optical 3D metrology. The maximum deviation from the nominal shape 0.54mm has been accomplished using discovered process parameters and printing strategies.
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Design of an experimental manifold suitable for a 3D print manufacturing
Zeman, Stanislav ; Křivohlavý, Petr (referee) ; Vaverka, Ondřej (advisor)
The target of this thesis was to design a method of mounting pressure sensors on an already designed shape of a flow distribution header. Furthermore, it was necessary to design a method of mounting the header on a laboratory stand and then find a method of surface treatment. This thesis was solved in these three structural nodes. Gradually, three variants were designed for the threaded connection of the distributor and the pressure sensor and then three variants of installation were designed for the selected threaded connection. The possibilities of mounting a header on a laboratory stand were designed in two variants. Finally, possible methods of surface treatment have been proposed to improve the impermeability through the wall of the header. The individual variants in each design node were compared with each other by their strength and the result was the final design of the flow distribution header. It was manufactured according to the given technological procedure and then its functionality was tested.
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Gear design with tolerance analysis
Křivohlavý, Petr ; Křupka, Jiří (referee) ; Svoboda, Petr (advisor)
The thesis is concerned with tolerances of machine elements. The thesis explains dimensional and geometrical tolerance, surface texture and their interdependence. On the basis of the stated facts a simple technique is established to be followed when setting tolerance of machine elements. The procedure is further applied on the transmission that was selected from the three models on hand. The technique is focused mostly on shaft and gear tolerance. The thesis should provide the reader with understanding of how to tolerate selected machine elements.
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Design of screw extruder for robotic 3D printing from pellets
Machač, Radim ; Škaroupka, David (referee) ; Křivohlavý, Petr (advisor)
The goal of this bachelor thesis was to design a screw extruder suitable for 3D printing, which will be able to process cheap plastic pellets instead of filament. The first part of the work is devoted to the extruder components, the extrusion process and the use of this polymer processing technology in the design of a screw extruder for 3D printing. An extruder model is created with regard to minimum dimensions and weight. During the design, requirements were set for ease of maintenance. The result is an extruder that enables both large-volume and small-volume printing, which, according to the calculations, is equal to the printing speed of ordinary 3D printers. This work will serve in the area of the usability of cheap plastic pellets as an input material for 3D printing. With its content, it also contributes to the development of screw extruder designs suitable for use in laboratories or industry.
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Design of shredder of 3D printing plastic parts
Lollek, Petr ; Koutecký, Tomáš (referee) ; Křivohlavý, Petr (advisor)
This bachelor thesis deals with the structural design of a shredder for plastic waste generated by 3D printing. The aim of the thesis is the design of a shredder whose output can be used to produce printing filament. The first part of the thesis consists of research of different types of shredders, an analysis of the basic methods of additive technology, the most used materials of FDM technology and the waste generated from them. The second part then evaluates conceptual options. The most suitable option is selected using the criteria established based on the conducted research and the objectives of the thesis. The practical part then deals with the verifying calculations and the actual structural design consisting of four main parts (drive unit, shredder assembly, the frame and enclosure)
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Mechanical properties of large scale 3D printing parts
Sýkora, Jakub ; Krčma, Martin (referee) ; Křivohlavý, Petr (advisor)
This study focuses on the mechanical properties of polymer samples printed using Fused Deposition Modeling (FDM) on a KUKA KR8 R1620 robotic arm with layer height and orientation relative to the bed as parameters. The samples were tested for tensile strength. The shape of the specimens was designed to eliminate the stress concentrations generated by the manufacturing process. The maximum stress values were compared with each other and the results were evaluated. In the end, it was evaluated how faster it is to print a sample using a 2 mm nozzle than a 0.4 mm nozzle. The results showed that the ductile materials (PETG and CPE) have significantly less load carrying capacity when printed on the robotic arm. For fragile materials (PLA and NonOilen) the difference is smaller. A sample can be printed up to 20 times faster using a 2 mm nozzle at a layer height of 1.5 mm than on a conventional printer at a layer height of 0.2 mm. The results of this work are intended to serve as a benchmark for further investigation of large-scale 3D printing. They can give a basic understanding of the properties and behaviour of materials printed using large diameter nozzles.
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Design of an experimental manifold suitable for a 3D print manufacturing
Zeman, Stanislav ; Křivohlavý, Petr (referee) ; Vaverka, Ondřej (advisor)
The target of this thesis was to design a method of mounting pressure sensors on an already designed shape of a flow distribution header. Furthermore, it was necessary to design a method of mounting the header on a laboratory stand and then find a method of surface treatment. This thesis was solved in these three structural nodes. Gradually, three variants were designed for the threaded connection of the distributor and the pressure sensor and then three variants of installation were designed for the selected threaded connection. The possibilities of mounting a header on a laboratory stand were designed in two variants. Finally, possible methods of surface treatment have been proposed to improve the impermeability through the wall of the header. The individual variants in each design node were compared with each other by their strength and the result was the final design of the flow distribution header. It was manufactured according to the given technological procedure and then its functionality was tested.
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Additive manufacturing of spatial trusses from polymeric materials
Křivohlavý, Petr ; Němeček, Stanislav (referee) ; Škaroupka, David (advisor)
This thesis is focused on creating polymer lattice struts without any necessary support in full length using robotic 3D printing. The aim of the thesis is to find suitable process parameters and printing strategies with respect to the accuracy of the polymer struts. A statistical model of effects of individual process parameters has been produced to achieve stated objectives. The model enables finding optimal process parameters. The printing strategies for thus established process parameters are tested to increase the accuracy of the finished print and the quality of the bonds between individual struts. The accuracy assessment is executed using optical 3D metrology. The maximum deviation from the nominal shape 0.54mm has been accomplished using discovered process parameters and printing strategies.
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Gear design with tolerance analysis
Křivohlavý, Petr ; Křupka, Jiří (referee) ; Svoboda, Petr (advisor)
The thesis is concerned with tolerances of machine elements. The thesis explains dimensional and geometrical tolerance, surface texture and their interdependence. On the basis of the stated facts a simple technique is established to be followed when setting tolerance of machine elements. The procedure is further applied on the transmission that was selected from the three models on hand. The technique is focused mostly on shaft and gear tolerance. The thesis should provide the reader with understanding of how to tolerate selected machine elements.
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