• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 37
  • 32
  • 18
  • 17
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 121
  • 74
  • 35
  • 24
  • 23
  • 21
  • 15
  • 13
  • 13
  • 13
  • 13
  • 13
  • 12
  • 10
  • 10
  • 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.
71

Povrchové změny v závislosti na parametrech FDM tisku / Surface changes based on FDM printing parameters

Čada, Jiří January 2016 (has links)
This thesis deals with a construction of modified RepRap 3D printer Rebel II which operates with Fused Deposition Modeling technology and selection of suitable criterion for printing. It mainly focuses on the temperature of the material being printed and speed of printing for three selected materials. Materials were selected based on availability in the market and their application. An experiment, focusing on surface changes of products as well as on the look of a fibre after passing through a nozzle, was performed.
72

Návrh a realizace 3D tiskárny s podporou síťového tisku / Design and implementation of 3D printer with network printing support

Špringer, Radek January 2016 (has links)
The goal of this thesis is to design a 3D printer type delta. To describe 3D printing technologies used by this printer, basic printer features and commercially available material used at the print and its comparison. To define all hardware components, which are necessary for construction of the 3D printer type delta. To create a proposal and construct an expansion board to which all hardware components of the printer will be connected. To optimize the print space heating and cooling of the printout. To extend the 3D printer with a Web server, which will ensure the network printing possibility.
73

Construction of Control system for syringe dispenser based on Printrbot 3D printer

An, Qi January 2020 (has links)
3D printers require a reliable and robust control system to provide the proper quality for printed parts. Dispenser 3D printers are widely used in various fields of scientific research. The goal of this project is to build a disperser 3D printer based on Printrbot 3D printer, design and implement the control system and software. This system was able to control the dispenser, performed the correct operation according to the instructions. The operating system was built by LabVIEW for file reading and printer control.
74

3D-skrivare inom bilindustrin : Additiv tillverkning gentemot traditionell tillverkning

Hajzeri, Tesi January 2018 (has links)
3D-teknologin uppmärksammas alltmer inom bilindustrin. Additiv tillverkning har redanimplementerats i stor utsträckning på exempelvis prototypframtagning. Det krävs dock drastiskteknologisk förändring för att möta de krav som ställs från konsumenter och samhället.Syftet med arbetet är att undersöka och uppmärksamma 3D-skrivarens roll inom bilindustrin.Studien fokuserar på resurseffektiv produktion med hjälp av 3D-skrivare. Målet är att utvärderavad införandet av 3D-skrivare innebär för denna industri och samhället. Vidare analyseras fördelaroch nackdelar med hjälp av litteraturstudier och intervjuer. Dessutom utreds det vilken inverkan3D-skrivare kan ha på marknadsstrukturer samt på företagens externa och interna dynamik.Sammanfattningsvis undersöks den additiva tillverkningens potential och utmaningar inombilindustrin.Det finns inga stora mängder forskning inom området eftersom 3D-skrivare inom bilproduktionhar införts ganska nyligen och implementeringen fortfarande befinner sig på forsknings- ochprototypframtagningsnivå. I detta arbete strävas det efter att ge en omfattande bild av 3Dskrivarimplementeringpå alla processer inom produktionssektorn.En slutsats från studien är att tekniken medför ett paradigmskifte för bilbranschen. Det konstaterasdock av resultatet att 3D-skrivateknologin behöver utvecklas och förbättras för att den skaanvändas i större utsträckning. Därtill krävs det mer forskning inom ämnet och en satsning påinförandet av kurser och laborationer inom additiv tillverkning i universitet, som ett nödvändigtsteg mot att främja 3D-teknologins frammarsch inom produktion. / 3D technology gets increasing attention in the automotive industry. Additive manufacturing hasalready been implemented to a significant extent, for example on prototype production. On theother hand, a drastic technological change is needed for the automotive industry to handle thedemands of consumers and society.In this research, the 3D printer's role in the automotive industry is highlighted and investigated. Inthe study, the focus is on resource-efficient manufacturing using 3D printers. The goal is toexamine what the introduction of 3D printers means for this industry and the society. Furthermore,pros and cons are analysed and obtained with the help of literature studies and interviews. Inaddition, the impact of 3D printers on market structures and on the company's external and internaldynamics is investigated. In summary, the potential and the challenges of additive manufacturingin the automotive industry are examined.There is not a substantial amount of research in the field since 3D printers have been introducedquite recently to the car manufacturing and implementation is still at research and prototypeproduction level. Therefore, the aim with this work is to provide a comprehensive image of 3Dprinter implementation on all processes in the production sector.One conclusion from the study is that this technology can lead to a paradigm shift for theautomotive industry. However, 3D printing technology needs to be developed and improved tobecome more widely used. More research on the subject is needed and an effort to introducecourses and laboratory work in additive manufacturing at universities is necessary to promote 3Dtechnology's advancement in production.
75

Nobjects: Eine Serie

Kaufer, Raoul 17 November 2023 (has links)
Die hier gezeigte Skulptur als Minimodel aus dem 3D-Drucker (aus Polyamid, im Maßstab 1 : 20) ist eine freie Fantasie innerhalb einer Werkserie über mögliche Objekte, die ich NOBJECTS nenne. Diese wechseln zwischen geo-, bio- und technomorpher Gestaltung. In diesem konkreten Beispiel habe ich unter Nutzung der 3D-Gestaltungssoftware “Zbrush“ das skulpturale Objekt aus einem schlichten Quadrat abgeleitet, aus dem ein Obelisk als tragende Säule hervorwächst, die in die vier Himmelrichtungen weist.
76

Hacking and Evaluating the Cybersecurity of an Internet Connected 3D Printer

Backlund, Linus, Ridderström, Linnéa January 2021 (has links)
Over the last few years, internet-connectivity hascome to be an expected feature of professional 3D printers.Connectivity does however come at a cost concerning the securityof the device. This project aimed to evaluate the cybersecurityof the Ultimaker S5 3D printer. The system was tested for themost likely and severe vulnerabilities based upon a threat modelmade on the product. The results show that the system’s localwebapplication is vulnerable to some common web-attacks thatallow the attacker to perform actions on the victims printer. / De senaste åren har internetuppkoppling blivit en självklar funktion hos professionella 3D skrivare. Upp-koppling kommer dock ofta på bekostnad av enhetens säkerhet. Detta projekt syftade till att utvärdera cybersäkerheten hos 3D skrivaren Ultimaker S5. En hotmodell gjordes och systemet penetrationstestades baserat på denna. Resultaten visar att enhetens lokala webbapplikationen är sårbar för några vanliga web-attcker som låter attackeraren exekvera oönskade funktioner på offrets skrivare. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm
77

Byggnadsmodellers anpassning inför 3D-utskift & dess användning / Building model´s adjustments before 3D-printing & its use

Elander, Sofia, Bolmstad, Elin January 2016 (has links)
Syfte: Att utreda hur digitala 3D-modeller bör anpassas inför utskrift i en 3D-skrivare samt undersöka hur en sådan modell kan användas i byggprocessens olika skeden. Metod: En fallstudie genomförs med en befintlig digital 3D-modell som utgångspunkt där intervjuer och action research används som datainsamlingsmetoder. Empirin jämförs och analyseras med det teoretiska ramverket som tagits fram genom litteraturstudier. Resultat: En fysisk 3D-modell skulle kunna användas i flera skeden i byggprocessen, huvudsakligen i idéskedet, produktionsskedet och genomgående processen som ett kommunikationsverktyg och vid reklam/försäljning/presentation för ökad förstående. Inför utskrift bör alla byggnadsdelar vara solida, detaljer bör raderas beroende på skala och komponenter bör bestå av samma material. Konsekvenser: Då intervjuerna utförs med personer med varierande kunskap och erfarenhet är det viktigt att beakta det faktum att förslag på användningsområden eventuellt inte är genomförbara i praktiken då dessa är önskemål. Trots detta kan användning av fysiska 3D-modeller rekommenderas i flera av byggprocessens skeden för ökad förståelse och bättre kommunikation, vilket även styrks av det teoretiska ramverket. Gällande anpassningar av en digital modell krävs en digital 3D-model som utgångspunkt och viss vana av 3D-projektering. Begränsningar: Då denna studie är en fallstudie utförd på ett specifikt fall, kan kunskap och rekommendationer inte generaliseras statistiskt på andra typer av byggnader. Dock kan resultatet i denna studie implementeras på liknande projekt om små justeringar tillämpas. På grund av det faktum att studien är kvalitativ med ett begränsat antal respondenter finns möjlighet till ett annat resultat om utförandet skett med andra förutsättningar. Nyckelord: BIM-modell, fysisk byggnadsmodell, 3D-modell, 3D-skrivare, 3D- utskrift / Purpose: To investigate how digital 3D models should be adapted to enable 3D printing for use in the construction process in its various stages. Method: A case study is conducted with an existing digital 3D-model where interviews and action research is used as a data collection method. The empirical data are compared and analyzed with the theoretical framework developed through literature studies. Findings: A physical 3D model can be used at several stages in the construction process, mainly in idea development stages, the production stage and throughout the process as a communication tool and for advertising/sales/presentation for increased understanding. Prior to printing, all parts of the building should be solid, details should be erased depending on the scale used and components should consist of the same material. Implications: Based on interviews with people with varying knowledge and experience within the subject, it is important to take into consideration the fact that the proposals on the fields of use may not be enforceable in reality since they are requests. Despite this, the use of physical 3D models can be recommended in several construction phases of the process for greater understanding and better communication, which is corroborated by the theoretical framework. Adaptions of a digital model require a digital 3D model as a prerequisite and a certain experience of 3D design. Limitations: Since this study is a case study conducted in a specific case, knowledge and recommendations cannot be generalized statistically to other types of buildings. However, with small adjustments, this study can be implemented in similar projects. Due to the fact that the study is qualitative with a limited number of interviewees, there is a possibility of a different result if the execution occurred with other conditions. Keywords: BIM model, physical building model, 3D model, 3D printer, 3D printing
78

Fabrication of Novel Structures to Enhance the Performance of Microwave, Millimeter Wave and Optical Radiators

Gbele, Kokou January 2016 (has links)
This dissertation has three parts which are distinctive from the perspective of their frequency regime of operation and from the nature of their contributions to the science and engineering communities. The first part describes work that was conducted on a vertical-external-cavity surface emitting-laser (VECSEL) in the optical frequency regime. We designed, fabricated, and tested a hybrid distributed Bragg reflector (DBR) mirror for a VECSEL sub-cavity operating at the laser emission wavelength of 1057 nm. The DBR mirror was terminated with a highly reflecting gold surface and integrated with an engineered pattern of titanium. This hybrid mirror achieved a reduction in half of the number of DBR layer pairs in comparison to a previously reported, successful VECSEL chip. Moreover, the output power of our VECSEL chip was measured to be beyond 4.0Wwith an optical-to-optical efficiency of 19.4%. Excellent power output stability was demonstrated; a steady 1.0 W output at 15.0 W pump power was measured for over an hour. The second part reports on an ultrafast in situ pump-probing of the nonequlibrium dynamics of the gain medium of a VECSEL under mode-locked conditions. We proposed and successfully tested a novel approach to measure the response of the inverted carriers in the active region of a VECSEL device while it was operating under passively mode-locked conditions. We employed the dual-frequency-comb spectroscopy (DFCS) technique using an asynchronous optical sampling (ASOPS) method based on modified time-domain spectroscopy (TDS) to measure the nonequilibrium dynamics of the gain medium of a phase-locked VECSEL that we designed and fabricated to operate at the1030 nm emission wavelength. Our spectroscopic studies used a probe pulse of 100 fs and an in situ pump pulse of 13 ps. We probed the gain medium of the VECSEL and recorded a depletion time of 13 ps, a fast recovery period of 17 ps, and 110 ps for the slow recovery time. Our scans thus demonstrated a 140 ps full depletion-recovery cycle in the nonequilibrium state. The third part discusses work in the microwave and millimeter wave frequency regimes. A new method to fabricate Luneburg lenses was proposed and demonstrated. This type of lens is well known; it is versatile and has been used for many applications, including high power radars, satellite communications, and remote sensing systems. Because the fabrication of such a lens requires intricate and time consuming processes, we demonstrated the design, fabrication and testing of a Luneburg lens prototype using a 3-D printing rapid prototyping technique both at the X and Ka-V frequency bands. The measured results were in very good agreement with their simulated values. The fabricated X-band lens had a 12 cm diameter and produced a beam having a maximum gain of 20 dB and a beam directivity (half-power beam width (HPBW)) ranging from 12° to 19°). The corresponding Ka-V band lens had a 7 cm diameter; it produced a beam with a HPBW about the same as the X-band lens, but with a maximum gain of more than 20 dB.
79

Prototypframtagning av robotarm med sex axlar genom 3D-skrivning

Norstedt, Erik, Bräne, Olof January 2019 (has links)
3D-skrivare är inte längre något som endast stora företag har råd att använda sig av, utan någonting som har tagit sig ända till konsumentmarknaden. Detta har givit både hobbyanvändare och småföretag tillgång till ett kraftfullt verktyg för iterativ design. Det görs idag även stora framsteg inom robotik som ger upphov till möjligheter för tillämpningar av både industri- och konsumentrobotar i framtiden. Komplexiteten i robotar gör 3D-skrivare till användbara verktyg när det kommer till att ta fram robotprototyper. Målet med detta projekt var därför att analysera fördelar och nackdelar med 3D-skrivning i samband med prototypframtagning av en robotarm med sex axlar som kunde utföra enkla pick-and-place-rörelser. Roboten designades i Fusion360 och skrevs ut med 3D-skrivare i PETG. En Arduino MEGA användes till att styra stegmotorer i robotens axlar och styrningen implementerade en analytisk lösning till robotens kinematisk modell. Resultatet var en fungerande prototyp som kunde programmeras till att flytta och rotera föremål. Ett antal förbättringar av prototypen går att göra, till exempel går det att öka robotens rörlighet genom att designa om delar för att tillåta att axlar rotera längre och att implementera ytterligare funktionalitet i programmet som accelerationsrampning av stegmotorer och rörelse längs förvald bana. Utifrån analys av 3D-skrivningens inverkan på projektet framgick det att 3D-skrivning verkar användbart i prototypframtagning om dess möjlighet till iterativ design är önskvärd, men att det passar ännu bättre till mindre projekt då robotens storlek hindrade möjligheten till att utnyttja iterativ design till fullo och på så sätt hindrades även effektiviteten i 3D-skrivningsprocessen.
80

Estudo da viabilidade técnica e projeto de um mini-cabeçote de extrusão com rosca para impressoras tridimensionais portáteis / Study of technical feasibility and design of a mini-screw extrusion head applied to three-dimensional desktop printers

Paulo Inforçatti Neto 08 March 2013 (has links)
Este trabalho tem o objetivo de apresentar o desenvolvimento do projeto informacional e do projeto conceitual de um mini-cabeçote vertical de extrusão com rosca de seção variável intercambiável. A montagem e a validação funcional deste cabeçote é feita na impressora 3-D Fab@CTI de forma intercambiável, na qual o projeto da estrutura foi baseada no projeto Fab@home. O projeto envolve o estudo sistemático utilizando o QFD para identificação dos requisitos do usuário e a escolha do \"cabeçote de deposição\", como característica técnica mais importante conduz o desenvolvimento do projeto conceitual e parte do projeto preliminar do mini-cabeçote vertical de extrusão. Utilizando análise morfológica no projeto conceitual se obteve a configuração do projeto, no qual foi possível dimensionar os principais componentes do sistema proposto: rosca/cilindro e sistema de acionamento. Os materiais considerados para o dimensionamento mecânico, bem como das estimativas das geometrias das seções da rosca foram poliamida e PCL, este último material foi escolhido por ser um biomaterial e por apresentar características físico-químicas mais criticas para o dimensionamento do dispositivo. O projeto conceitual foi fabricado e montado para demonstrar sua funcionalidade de extrusão utilizando um material pastoso e pó sem processo de aquecimento. Este trabalho apresenta o projeto e a validação técnica de um mini-cabeçote intercambiável de extrusão por rosca para utilização em impressoras 3-D utilizadas em manufatura aditiva. A abordagem sistemática de projeto demonstra a importância de técnicas de metodologia de projeto durante o desenvolvimento de um produto, a fim de se obter qualidade no projeto de engenharia. / The purpose of this work is to present the study of the informational and conceptual design of the vertical mini-screw extrusion head applied to portable and open source additive manufacturing machine. The design was validated considering the proposal of interchangeable heads applied to Brazilian 3-D printer based on Fab@home mechanical design. It was developed a systematic study using QFD to identify user\'s requirements, supporting the choice of a \"deposition head\" as the most important technical characteristic, leading the design development of a mini vertical system based on a extrusion screw with variable section. The conceptual design using the morphological analysis defined the design configuration, allowing to make a pre-calculation of the main components of the proposed head: screw, barrel and actuation system. The deposition materials, considered for the theoretical calculations, were polyamide and PCL, being the last a biocompatible polymer. This choice lead to critical physicochemical properties related to system design. The conceptual design was manufactured and assembled, demonstrating its functionality to extrude a paste like and powder materials without heating. This work presented the design and the validation of an interchangeable mini-extruder screw head developed to a portable 3-D printer used in additive manufacturing process. The systematic approach demonstrated the importance of the design methodology tools during the product development to obtain quality in the design engineering.

Page generated in 0.0656 seconds