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Vid additiv tillverkning med EBM-metoden har hanteringen och återcirkulationen av titanpulver en betydande roll för effektivitet, kvalitet och spårbarhet i tillverkningsprocessen. I takt med att additivt tillverkade produkter fått större marknadsandelar och används i alltmer ingenjörsmässiga applikationer ställs högre krav på tillverkningsprocesserna och därmed pulverhanteringen.   Detta projekt initierades då företaget AIM Sweden såg behovet av att införa ny utrustning i form av en pulverhanteringsstation, med syftet att erhålla en mer effektiv och spårbar pulverhantering vid deras EBM tillverkning med maskinerna Arcam EBM Q10- och Q20plus.   Projektet har genomförts som ett examensarbete för maskiningenjörsutbildningen vid Mittuniversitetet. Målet var att ta fram ett konstruktionsunderlag för en utrusning som uppfyllde identifierade krav och önskemål från uppdragsgivaren AIM Sweden och de närmsta intressenterna för projektet.   Utrustningen togs fram med produktutvecklingsmetodik i fem projektfaser där framstegen från varje milstolpe redovisades för uppdragsgivaren under projektets gång.   Resultatet av projektet bestod i ett konstruktionsunderlag av en pulverhanteringsstation med funktioner för att väga, transportera och homogenisera titanpulver. Stationen skapar förutsättningar för en mer effektiv tillverkningsprocess med förenklad spårbarhetsdokumentation. Detta kan bidra till möjlighet att leverera produkter till fler typer av kunder och en ökad lönsamhet för AIM Sweden.   Innan utrustningen kan tillverkas krävs tester och vidare arbete i form av val av standardkomponenter, konstruktion av drivningssystem samt en mer omfattande ekonomisk kalkyl. / <p>Betyg 2020-07-14</p>

PURPOSE: To analyze surface roughness, the edge chipping of different CAD/CAM bur milled dental materials (bar and crown design of 1.0mm and 1.5mm thickness), correlate the effect of machining damage on the material strength, compare the flexural strength of bur milled versus sectioned CAD/CAM blocks and evaluate the tool wear after milling. MATERIALS AND METHODS: Five dental CAD/CAM materials were used: Lithium disilicate glass-ceramic (IPS e.max CAD), Leucite-reinforced glass-ceramic (IPS Empress CAD), Feldspathic porcelain (Vitablocs Mark II), Feldspar ceramic-polymer infiltrated (Enamic), and composite resin (Lava Ultimate). Ten rectangular bars with dimensions of 4 mm × 2 mm × 14 mm were milled using a new set of burs for each material. Then, ten crowns of each material with thicknesses of 1.0 mm and 1.5 mm were milled after scanning a standard aluminum die with corresponding marginal thickness. The bars surface roughness was measured. Then, three specimens were selected for the edge chipping analysis using (SEM). Thereafter, 3-point bend test was used to test the flexural strength of bur milled and saw cut bars with the same dimensions. For the crowns, load to failure test was used. One-way ANOVA and Tukey HSD post hoc tests to determine the difference between the groups using JMP13.0 with α=0.05. RESULTS AND CONCLUSIONS: The surface roughness and edge chipping was significantly affected by the material composition. Comparison of the flexural strength of bur milled to sectioned bars, IPS e.max CAD and IPS Empress CAD show statistically significant less flexural strength (p<0.001). A strong correlation was found between the decrease in flexural strength and the chipping length on the central tensile side of the bur milled materials (R2=0.62, p=0.01). Crown thickness significantly affects the edge chipping as 1.5 mm crown thickness has more edge chipping than 1.0 mm crowns. However, no correlation is found between the load to failure test for the crown design and the edge chipping for 1.5mm and 1.0 mm thickness crowns. Tool wear is significantly affected by the material type. / 2021-07-31

Collaboration has always been critical to the success of new product development teams, and the advent of geographically dispersed teams has significantly altered the way that team members interact. Multi-user computer-aided design (MUCAD) and crowdsourcing are two results of efforts to enable collaboration between geographically dispersed individuals. In this research, a study was done to investigate the differences in performance between MUCAD and single-user CAD teams, in which teams competed to create the best model of a hand drill. This was done across a three-day period to recreate the scenario found in industry. It was found that MUCAD increases awareness of teammates' activities and increases communication between team members. Different sources of frustration for single-user and multi-user teams were identified, as well as differing patterns of modeling style. These findings demonstrate that MUCAD software has significant potential to improve team collaboration and performance. A second study explored a number of potentially significant factors in MUCAD team performance, including leadership, design style, unfamiliar parts, knowledge transfer, individual experience, and team composition. In this study, teams of undergraduate mechanical engineering students worked together to complete tasks using NXConnect, a MUCAD plugin for NX developed at Brigham Young University. A primary finding was that having an appointed leader for a MUCAD team improves performance, in particular when that leader works with the team in creating the CAD model. It was also found that creating a framework to aid in organizing and coordinating the creation of the CAD model may decrease the time required for completion. In the final study, the possibility of using crowdsourcing to complete complex product design tasks was explored. In this study, a process for crowdsourcing complex product design tasks was developed, as well as a website to act as the platform for testing this process. A crowd consisting of engineering and technology students then worked together on the website to design a frisbee tracking device. The crowd was able to collaborate to accomplish some detailed product design tasks, but was not able to develop a complete product. Major findings include the need for more formal leadership and crowd organization, the need for better decision making mechanisms, and the need for a better model for engaging crowd members on a consistent basis. It was also found that crowd members had a greater willingness to pay for the product they developed than individuals who had not worked on the project. Results also show that although crowd members were often frustrated with the collaboration process, they enjoyed being able to work with a large group of people on a complex project.

Collaboration has always been critical to the success of new product development teams, and the advent of geographically dispersed teams has significantly altered the way that team members interact. Multi-user computer-aided design (MUCAD) and crowdsourcing are two results of efforts to enable collaboration between geographically dispersed individuals. In this research, a study was done to investigate the differences in performance between MUCAD and single-user CAD teams, in which teams competed to create the best model of a hand drill. This was done across a three-day period to recreate the scenario found in industry. It was found that MUCAD increases awareness of teammates' activities and increases communication between team members. Different sources of frustration for single-user and multi-user teams were identified, as well as differing patterns of modeling style. These findings demonstrate that MUCAD software has significant potential to improve team collaboration and performance. A second study explored a number of potentially significant factors in MUCAD team performance, including leadership, design style, unfamiliar parts, knowledge transfer, individual experience, and team composition. In this study, teams of undergraduate mechanical engineering students worked together to complete tasks using NXConnect, a MUCAD plugin for NX developed at Brigham Young University. A primary finding was that having an appointed leader for a MUCAD team improves performance, in particular when that leader works with the team in creating the CAD model. It was also found that creating a framework to aid in organizing and coordinating the creation of the CAD model may decrease the time required for completion. In the final study, the possibility of using crowdsourcing to complete complex product design tasks was explored. In this study, a process for crowdsourcing complex product design tasks was developed, as well as a website to act as the platform for testing this process. A crowd consisting of engineering and technology students then worked together on the website to design a frisbee tracking device. The crowd was able to collaborate to accomplish some detailed product design tasks, but was not able to develop a complete product. Major findings include the need for more formal leadership and crowd organization, the need for better decision making mechanisms, and the need for a better model for engaging crowd members on a consistent basis. It was also found that crowd members had a greater willingness to pay for the product they developed than individuals who had not worked on the project. Results also show that although crowd members were often frustrated with the collaboration process, they enjoyed being able to work with a large group of people on a complex project.

Today's thinning operations in forestry are managed by using large thinning machines that have a negative impact on the environment due to their reliance on non-renewable energy source and the creation of strip roads. To address this problem, the company utilizes drones equipped with a harvesting tool for thinning operations and today there are no field service stations for inspecting and maintaining a harvesting tool. The purpose of this thesis is to design a service station for the harvesting tool while also formulating a set of requirements. To accomplish this goal, a data collection process was undertaken with interviews and workshops to gain valuable insights into the requirements and functions. The next step involved concept generation and evaluating all concepts using workshops and Pugh's concept selection matrix. The outcome of this work is a concept for a service station that can fit inside a container, featuring an equipped work area and a docking station for the harvesting tool. In its final iteration, the service station enables damaged harvesting tool to be docked, inspected, and maintained. The final version does not support the docking of a damaged tool with the intent to immediately retrieve another fully functional one. Therefore, there is opportunity to explore further concepts that align with the company’s long-term goals.

Razorback är ett företag konsultföretag i Lund som främst fräser ut detaljer till konstruktioner i polyoximetylen (POM) och polyeten (PE). När detaljerna har frästs ut sitter det kvar lösa spån som behöver tas bort innan detaljerna ska monteras ihop. Idag utförs spånborttagningen manuellt av en person vilket är tidskrävande. En batch består av 75 detaljer som tar ungefär 20 minuter att rengöra för hand. Syftet med detta arbete är att underlätta och effektivisera borttagningen av spån från detaljer när de har frästs ut. Målet är ta fram ett koncept som ska fyllas med detaljer, startas och tömmas av en person, spånborttagningen ska utföras utan handarbete. Utifrån angivna kravspecifikationer från Razorback tas det fram ett koncept för en spånborttagare. Under konceptgenereringen delas huvudproblemet för spånborttagaren upp i delproblem för att för att underlätta arbetets gång. Det görs en extern sökning för att samla information och inspriration till konceptet och den interna sökningen. Under den interna sökningen generas lösningar till en spånborttagare med hjälp av brainwriting. Ett koncept väljs på ett systematiskt sätt med en konceptpoängsättningsmatris för att vidareutveckla. Beräkningar på detaljernas luftmotstånd görs för att se hur stor hastighet luftflödet behöver ha för detaljerna ska röra på sig och få spånen att lossna. Det valda konceptet omsätts till en prototyp som testas för att se hur lång tid det tar att suga upp alla spån. För att optimera luftflödet utförs luftflödessimuleringar på konceptet och en 3D-modell av konceptet tas fram med CAD-programmet solidworks.  Det strävas även efter att jobba med de 17 globala målen med konceptet då plasten är återviningsbar och ska kunna samla upp spånen så det inte hamnar i omvärlden. Det resulterade i ett koncept som är lätt att manövrera, då detaljerna hälls i, spånbortagningen sker med luftflöde från en grovdammsugare och tömningen sker genom att öppna en lucka i botten. / Razorback is a company in Lund that mills details in polyoxymethylene (POM) and polyethylene (PE). When the details are milled there are still some plastic chips stuck that needs to be removed before mounting. Today the company removes the chips manually by hand which takes time and is ineffective. One batch equals 75 details which takes 20 minutes to remove by hand. The purpose of this project is to make the chip removing process easier and more efficient by generating a concept that receives details, get started and be emptied by one person, the chip removing process shall be executed without handwork.  A concept shall be developed from the required specifications from Razorback. Based on specified requirement specifications from Razorback, a concept for a chip remover is developed. During concept generation, the main problem for the chip remover is divided into sub-problems in order to facilitate the flow of work. An external search is done to gather information and inspiration for the concept and the internal search. During the internal search, solutions for a chip remover are generated using brainwriting. A concept is selected in a systematic way using a concept scoring matrix to further develop. Calculations on the air resistance of the parts are made to see how fast the air flow needs to be for the parts to move and cause the chips to come loose. The chosen concept is translated into a prototype that is tested to see how long it takes to suck up all the shavings. To optimize the air flow, air flow simulations are performed on the concept and a 3D model of the concept is produced with the CAD program solidworks. It strives to work towards the 17 sustainable development goals with the concept because the plasticis recyclable and must be able to be collected so that it doesn't end up in the environment. It resulted in a concept that is easy to operate, since the details is added, the chip removal is performed by air flow from a vacuum cleaner and emptied by open a hatch in the bottom.

Introduction: No commercially available solution to improve the teaching of a crown preparation directly on typodont teeth exists at the moment. To fill this gap and support the supervisors of dental courses, a printable and inexpensive tooth was created for structured self-assessment. The aim of this study was to test this printable tooth under realistic pre-clinical situations. Materials and methods: A two-coloured, double-layer practice tooth was developed. This tooth was consisting of a layer for a correct preparation and the crown. All printed teeth were produced with a stereolithographic printer. 35 voluntary secondyear dental students in the second pre-clinical course in prosthodontics were randomly divided into two groups. All students had experience with typodont teeth and models. The first group was trained on four standard model teeth. The second group used model teeth for the first and fourth attempt and printed teeth for second and third attempt. The preparations of the students were scanned by an in-lab scanner and the surface deviations in contrast to a perfect preparation were measured. The differences between the first and fourth attempt were calculated. Benefits of the printed tooth were also evaluated by a questionnaire using German school grades completed by the students (1 = Excellent, 2 = Good, 3 = Satisfactory, 4 = Adequate, 5 = Poor, 6 = Unsatisfactory). Results: The workflow was feasible and cost-effective regarding the production of the printed teeth. The overall rating of the printed tooth in the questionnaire was good (Ø 2.1 ± 0.22). Students reported different advantages of this method in the free text. The comparison of the preparation between the first and fourth attempt showed that there was a significant better preparation with the printed teeth. The complete preparation had median values of 0.05 mm (Group1: standard model tooth) and −0.03 mm (Group2: printed tooth) (P = .005). Divided into single surfaces, the vestibular and occlusal regions were significantly better. The vestibular surface was 0.11 mm (Group1) and −0.04 mm (Group2) (P = .018). The occlusal surface was 0.13 mm (Group1) and −0.05 mm (Group2) (P = .009). Conclusions: The aim of this study was fulfilled. The printed tooth was tested successfully in a pre-clinical course. The feasibility of this teaching concept was confirmed by the questionnaire and the analysis of the preparation form. A significant difference to a standard model tooth was measurable. The students had the possibility to learn a correct crown preparation on a standardised two-layered tooth with included preparation. This printed tooth enabled the students to control the crown preparation directly on their own. / Einleitung: Es gibt derzeit keine kommerziell erhältliche Lösung zur Verbesserung des Erlernens einer Kronenpräparation an Modellzähnen. Um diese Lücke zu schließen und die Betreuer von zahnmedizinischen Kursen zu unterstützen, wurde ein druckbarer und kostengünstiger Zahn zur strukturierten Selbsteinschätzung entwickelt. Das Ziel dieser Studie war es, diesen druckbaren Zahn unter realistischen vorklinischen Situationen zu testen. Materialien und Methoden: Es wurde ein zweifarbiger, zweischichtiger Übungszahn entwickelt. Dieser Zahn bestand aus einer korrekten Präparationsschicht und der Zahnkrone. Alle gedruckten Zähne wurden mit einem Stereolithografiedrucker hergestellt. 35 freiwillige Zahnmedizinstudenten des zweiten vorklinischen Kurses im zweiten Jahr, wurden nach dem Zufallsprinzip in zwei Gruppen aufgeteilt. Alle Studenten hatten Erfahrung mit Modellzähnen. Die erste Gruppe trainierte an vier Standard-Modellzähnen. Die zweite Gruppe verwendete Modellzähne für den ersten und vierten Versuch und gedruckte Zähne für den zweiten und dritten Versuch. Die Präparationen der Studenten wurden mit einem In-Lab-Scanner gescannt und die Oberflächenabweichungen im Gegensatz zu einer perfekten Präparation gemessen. Die Unterschiede zwischen dem ersten und vierten Versuch wurden berechnet. Der Nutzen des gedruckten Zahnes wurde durch einen Fragebogen mit deutschen Schulnoten von den Studierenden bewertet (1 = Ausgezeichnet, 2 = Gut, 3 = Befriedigend, 4 = Ausreichend, 5 = Schlecht, 6 = Unbefriedigend). Ergebnisse: Der Arbeitsablauf war praktikabel und kostengünstig in der Herstellung der der gedruckten Zähne. Die Gesamtbewertung des gedruckten Zahns im Fragebogen war gut (Ø 2,1 ± 0,22). Die Studenten berichteten verschiedene Vorteile dieser Methode im Freitext. Der Vergleich der Präparation zwischen dem ersten und vierten Versuch zeigte, dass mit den gedruckten Zähnen eine signifikant bessere Präparation erreicht wurde. Die vollständige Präparation hatte Medianwerte von 0,05 mm (Gruppe1: Standardmodellzahn) und -0,03 mm (Gruppe2: gedruckter Zahn) (P = .005). Aufgeteilt in einzelne Flächen waren die vestibulären und okklusalen Bereiche signifikant besser. Für die vestibuläre Fläche ergaben sich folgende Werte 0,11 mm (Gruppe1) und -0,04 mm (Gruppe2) (P = .018). Für die Okklusalfläche ergab sich eine Abweichung von 0,13 mm (Gruppe1) und -0,05 mm (Gruppe2) (P = .009). Schlussfolgerungen: Das Ziel dieser Studie wurde erfüllt. Der gedruckte Zahn wurde erfolgreich in einem vorklinischen Kurs getestet. Die Machbarkeit dieses Lehrkonzepts wurde durch den Fragebogen und die Analyse der Präparationsform bestätigt. Ein signifikanter Unterschied zu einem Standard-Modellzahn war messbar. Die Studenten hatten die Möglichkeit eine korrekte Kronenpräparation an einem standardisierten zweischichtigen Zahn mit eingebauter Präparation zu üben. Dieser gedruckte Zahn ermöglichte es den Studenten die Kronenpräparation selbst zu kontrollieren.

No description available.

Industry is constantly looking for ways to bring new or derivative products to market in the shortest amount of time for the least amount of money. To accomplish this, Industry has adopted Computer Aided Engineering (CAX) tools that perform structural, flow, manufacturing, and cost analysis. The way in which a company utilizes these CAX tools can determine the success of these new products. One of these tools that Industry often struggles with in the preliminary design of a product is Computational Fluid Dynamics (CFD). Some of the challenges presented by CFD are the time it takes to create a CAD model, generate a valid grid for analysis, obtain a solution, post-process results, and review the result. The objective of this thesis is to develop an approach that will reduce the time it takes to go from a concept to a solution ready for review. This approach, addresses how to first, build CAD model for use in downstream applications, second, automate the grid generation process, and third, automate the post process and documentation of the results. Using this approach a conceptual study of a two stream mixing problem was performed. The approach showed that the creation of the first model took about twenty percent longer than the standard practice used in industry today. However, once the first model was completed, different concepts could be added to the CAD model and be ready for analysis in less than half the time when compared to standard practices. This time savings can then be used to explore more concepts. After each model was analyzed, it was post-processed using an automated script. With the post-processed results the Design Review Tool (DRT) was developed to automate the documentation of the results. Using the DRT each post-processed case was organized into a web page and saved for review in less than five seconds. This approach will enable the aerospace, automotive, and other industries to use CFD to more effectively explore the design space in the development of new and derivative products. This research demonstrates the process to reduce the time required to go from CAD-to-Grid, postprocess the results, and create the documentation needed to develop new products.