Understanding Process Parameter Effects of RepRap Open-Source Three-Dimensional Printers Through a Design of Experiments Approach

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Antonio Lanzotti ◽  
Massimo Martorelli ◽  
Gabriele Staiano
Keyword(s):  
Design Of Experiments ◽  
Open Source ◽  
Process Parameters ◽  
Laser Scanner ◽  
Scientific Data ◽  
Engineering System ◽  
Main Process ◽  
The Impact ◽  
Selection Of

With a view to enabling additive manufacturing (AM) processes, today, open-source, low-cost 3D printers are systems with great potential. However there is a significant lack of scientific data on the performance of open-source 3D systems and on the selection of adequate process parameters that can help to improve the quality of the parts. The purpose of this paper is to assess the effects of the main process parameters on the dimensional accuracy of a specific open-source 3D printer, the RepRap Prusa-Mendel I2. This study consisted of a benchmarking part, involving elementary shapes representing a series of different features. By means of a full factorial DoE (Design of Experiments), with three factors (layer thickness, deposition speed, and flow rate), three levels, and three replications, 81 parts were obtained. Subsequently, a laser scanner (D700 Laser Scanner—3Shape, Denmark) was used as high resolution reverse engineering system in order to evaluate the variation between real parts and nominal geometry. The impact of the main process parameters was evaluated and optimal combinations were analyzed. On the basis of the results obtained in the experiments, practical suggestions for the settings of common process parameters were formulated. Test results serve to improve the quality of AM parts through the most appropriate selection of the main process parameters.

On the Geometric Accuracy of RepRap Open-Source Three-Dimensional Printer

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Antonio Lanzotti ◽  
Domenico Maria Del Giudice ◽  
Antonio Lepore ◽  
Gabriele Staiano ◽  
Massimo Martorelli
Keyword(s):  
Open Source ◽  
Process Parameters ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Scientific Data ◽  
Correct Selection ◽  
Geometric Feature ◽  
Main Process ◽  
Geometric Features ◽  
The Impact

In the field of additive manufacturing (AM) processes, there is a significant lack of scientific data on the performance of open-source 3D printers in relation to process parameter values. The purpose of this paper is to assess the impact of the main process parameters on the accuracy of a set of typical geometric features, as obtained with an open-source 3D printer, the RepRap Prusa-Mendel I2. For this purpose, a benchmarking part was set up, composed of elementary shapes, representing a series of different geometric features. By means of a DoE approach, it was possible to assess the effects of two process parameters—layer thickness (Lt) and flow rate (Fr)—on five geometric features: cube, sphere, cylinder, cone, and angled surface. A high resolution Laser Scanner was used to evaluate the variation between the acquired geometric feature and the corresponding 3D computer-aided design (CAD) nominal model. On the basis of experimental results, it was possible to analyze and discuss the main effects of the above-mentioned process parameters on each geometric feature. These results can help RepRap users in the correct selection of process parameters with the aim of improving the quality of prototypes.

scholarly journals The impact of process parameters on mechanical properties of parts fabricated in PLA with an open-source 3-D printer

2015 ◽  
Vol 21 (5) ◽  
pp. 604-617 ◽  
Author(s):  
Antonio Lanzotti ◽  
Marzio Grasso ◽  
Gabriele Staiano ◽  
Massimo Martorelli
Keyword(s):  
Mechanical Properties ◽  
Open Source ◽  
Process Parameters ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Testing Machine ◽  
Main Process ◽  
Content Type ◽  
Fused Deposition ◽  
The Impact

Purpose – This study aims to quantify the ultimate tensile strength and the nominal strain at break (ɛf) of printed parts made from polylactic acid (PLA) with a Replicating Rapid prototyper (Rep-Rap) 3D printer, by varying three important process parameters: layer thickness, infill orientation and the number of shell perimeters. Little information is currently available about mechanical properties of parts printed using open-source, low-cost 3D printers. Design/methodology/approach – A computer-aided design model of a tensile test specimen was created, conforming to the ASTM:D638. Experiments were designed, based on a central composite design. A set of 60 specimens, obtained from combinations of selected parameters, was printed on a Rep-Rap Prusa I3 in PLA. Testing was performed using a JJ Instruments – T5002-type tensile testing machine and the load was measured using a load cell of 1,100 N. Findings – This study investigated the main impact of each process parameter on mechanical properties and the effects of interactions. The use of a response surface methodology allowed the proposition of an empirical model which connects process parameters and mechanical properties. Even though results showed a high variability, additional ideas on how to understand the impact of process parameters are suggested in this paper. Originality/value – On the basis of experimental results, it is possible to obtain practical suggestions to set common process parameters in relation to mechanical properties. Experiments discussed in the present paper provide a variety of data and insight regarding the relationship among the main process parameters and the stiffness and strength of fused deposition modeling-printed parts made from PLA. In particular, this paper underlines the shortage in existing literature concerning the impact of process parameters on the elastic modulus and the strain to failure for the PLA. The experimental data produced show a good degree of compliance with analytical formulations and other data found in literature.

scholarly journals Effects of Process Parameters on the Color Quality of Anthocyanin-Based Colorants from Conventional and Microwave-Assisted Aqueous Extraction of Sweet Potato (Ipomoea batatas L.) Leaf Varieties

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 103
Author(s):  
Jin Mark D. G. Pagulayan ◽  
Aprille Suzette V. Mendoza ◽  
Fredelyn S. Gascon ◽  
Jan Carlo C. Aningat ◽  
Abigail S. Rustia ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Process Parameters ◽  
Ipomoea Batatas ◽  
Extraction Methods ◽  
Aqueous Extraction ◽  
Potato Leaf ◽  
Microwave Assisted ◽  
Color Quality ◽  
The Impact

The study aimed to evaluate the effects of process parameters (time and raw material weight (RMW)) of conventional (boiling for 10–45 min) and microwave-assisted (2–8 min) aqueous extraction on the color quality (i.e., lightness (L*), chroma (C*), and hue (H°) of anthocyanin –based colorants of red and Inubi sweet potato (Ipomoea batatas L.) leaves. Using response surface methodology, it was found that RMW and boiling time (BT) and microwave time (MT) generally had a significant (p < 0.05) effect on the color quality of the extract from both extraction methods. The effects were found to vary depending on the extraction method and variety of the leaves used. Both extraction methods produced a brown to brick-red extract from the Inubi variety that turned red-violet to pink when acidified. The red sweet potato leaves produced a deep violet colored extract that also turned red-violet when acidified. It is recommended that the anthocyanin content of the extracts be measured to validate the impact of the methods on the active agent. Nevertheless, the outcomes in this study may serve as baseline data for further studies on the potential of sweet potato leaf colorants (SPLC) as a colorant with functional properties.

scholarly journals Knowledge sharing in open source software communities: motivations and management

2015 ◽  
Vol 19 (4) ◽  
pp. 791-813 ◽  
Author(s):  
Zilia Iskoujina ◽  
Joanne Roberts
Keyword(s):  
Knowledge Sharing ◽  
Open Source ◽  
Open Source Software ◽  
Online Communities ◽  
Descriptive Analysis ◽  
Online Questionnaire ◽  
Content Type ◽  
The Individual ◽  
The Impact

Purpose – This paper aims to add to the understanding of knowledge sharing in online communities through an investigation of the relationship between individual participant’s motivations and management in open source software (OSS) communities. Drawing on a review of literature concerning knowledge sharing in organisations, the factors that motivate participants to share their knowledge in OSS communities, and the management of such communities, it is hypothesised that the quality of management influences the extent to which the motivations of members actually result in knowledge sharing. Design/methodology/approach – To test the hypothesis, quantitative data were collected through an online questionnaire survey of OSS web developers with the aim of gathering respondents’ opinions concerning knowledge sharing, motivations to share knowledge and satisfaction with the management of OSS projects. Factor analysis, descriptive analysis, correlation analysis and regression analysis were used to explore the survey data. Findings – The analysis of the data reveals that the individual participant’s satisfaction with the management of an OSS project is an important factor influencing the extent of their personal contribution to a community. Originality/value – Little attention has been devoted to understanding the impact of management in OSS communities. Focused on OSS developers specialising in web development, the findings of this paper offer an important original contribution to understanding the connections between individual members’ satisfaction with management and their motivations to contribute to an OSS project. The findings reveal that motivations to share knowledge in online communities are influenced by the quality of management. Consequently, the findings suggest that appropriate management can enhance knowledge sharing in OSS projects and online communities, and organisations more generally.

The impact of stigma and discrimination on the quality of life and social disability in persons with a diagnosis of mental disorder. A pilot study

2017 ◽  
Vol 41 (S1) ◽  
pp. S571-S571
Author(s):  
T.M. Gondek ◽  
K. Kotowicz ◽  
A. Kiejna
Keyword(s):  
Quality Of Life ◽  
Pilot Study ◽  
Mental Disorders ◽  
Mental Disorder ◽  
Public Information ◽  
Scientific Data ◽  
Social Disability ◽  
Stigma And Discrimination ◽  
The Impact

Stigma and discrimination of persons diagnosed with mental disorder is a common issue. In many European countries, research studies on the prevalence and implications of this problem are conducted in order to better understand how to overcome it. In Poland, there is a scarcity of such studies, what results in neglecting this issue by the policy makers. The objective of the study is to assess the prevalence of stigma and discrimination affecting the patients hospitalized in psychiatric day units and in-patient wards between 2016–2017 as well as to analyze the relationship between the stigma and the quality of life and social disability in persons with a mental disorder diagnosis of F20–F48 according to ICD-10, aged 18–65, in a day ward and an in-patient ward settings. The pilot study presents the data gathered from a preliminary sample of 20 patients of both genders diagnosed with the aforementioned mental disorders, equaling 10 per cent of the targeted total study sample. The quality of life is assessed with WHOQOL-Bref, WHO-5 questionnaire and Rosenberg self-esteem scale, while social disability is measured with the second version of the Groningen Social Disabilities Schedule. The assessment of the impact of stigma on the social disability of persons with mental disorders and their quality of life can be useful in the context of developing evidence-based interventions for these persons, while it could also provide the scientific data to support public information campaigns aiming at tackling the stigma against persons with mental disorders in Poland.Disclosure of InterestThe authors have not supplied their declaration of competing interest.

Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li
Keyword(s):  
Process Parameters ◽  
Large Diameter ◽  
Dimensional Accuracy ◽  
Optimization Method ◽  
Main Process ◽  
Shape Accuracy ◽  
Line Pipe ◽  
Factors Affecting ◽  
Array Optimization

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

scholarly journals Wine preferences based on intrinsic attributes: A tasting experiment in Alto Adige/Südtirol province

2021 ◽  
pp. 129-134
Author(s):  
Luigi Fabbris ◽  
Alfonso Piscitelli
Keyword(s):  
Food Product ◽  
Fractional Factorial ◽  
Region Of Origin ◽  
Double Blind ◽  
White Wines ◽  
Grape Varieties ◽  
The Impact ◽  
Administration Procedure ◽  
Selection Of

Different methods have been developed by researchers in modelling wine consumers purchase behaviour. The quality of a food product is described by a set of characteristics ascribable to the intrinsic and extrinsic product attributes (Olson and Jacoby, 1972). Price, brand, region of origin, grapes and gained awards are the key extrinsic attributes and physical characteristics of the wine such as taste and flavour are intrinsic attributes. This paper addresses the problem of measuring the intrinsic attributes that characterise the wine, based on specific characteristics and the impact on consumers in terms of preferences. To this end, a fractional factorial experiment held on a selection of white wines of the Alto Adige/Südtirol province in Italy. The sensorial experiment involved a voluntary sample of 33 mild wine consumers and concerned 6 grape varieties typical of that territory. For each variety, two producing cellars were selected for a total of 12 evaluated wines. The experiment followed a double-blind administration procedure to the sample and a paper questionnaire was used to elicit the consumers’ opinions on the tasted wines. The results show that intrinsic attributes, such as taste-olfactory intensity, harmony and olfactory complexity, are the drivers used in combination by consumers to rank wines in order of preference.

The Impact of Agile Methodologies on the Quality of Information Systems

2010 ◽  
Vol 1 (1) ◽  
pp. 41-56 ◽  
Author(s):  
Kenneth E. Kendall ◽  
Sue Kong ◽  
Julie E. Kendall
Keyword(s):  
Information Systems ◽  
Project Managers ◽  
Quality Of Information ◽  
Software Developers ◽  
Agile Methodologies ◽  
Development Methodology ◽  
Strategic Process ◽  
The Impact ◽  
Selection Of

Systems developers and IT project managers who apply agile methods for developing information systems (IS) subscribe to a set of values and principles. This adherence to a set of values and principles, along with a passion or fervor surrounding the agile philosophy, made us question whether the adoption of agile methodologies has an effect on information systems built, and in particular, the quality of the IS developed. In this paper we construct a conceptual model, conduct a survey of software developers, and analyze our results, which support our hypotheses about the importance of the strategic selection of a development methodology. We conclude that practicing project managers should consider the decision to use certain methodologies as part of the strategic process.

The Mechanisms of Material Removal in the Fluidized Bed Machining of Polyvinyl Chloride Substrates

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
M. Barletta ◽  
V. Tagliaferri ◽  
F. Trovalusci ◽  
F. Veniali ◽  
A. Gisario
Keyword(s):  
Fluidized Bed ◽  
Polyvinyl Chloride ◽  
Process Parameters ◽  
Material Removal ◽  
High Speed ◽  
Mesh Size ◽  
Main Process ◽  
Machining Time ◽  
Polymeric Substrates ◽  
The Impact

In this paper, the mechanisms of material removal during the fluidized bed machining (FBM) of polymeric substrates are analyzed. Cylindrical components composed of polyvinyl chloride (PVC) were exposed to the impact of abrasives while rotating at high speed within a fluidization column. The interaction between the Al2O3 abrasive media and the PVC surfaces was studied to identify the effect of the main process parameters, such as the machining time, the abrasive mesh size, and the rotational speed. The change in the surface morphology as a function of the process parameters was evaluated using field emission gun—scanning electron microscopy (FEG-SEM) and contact gauge profilometry. An improvement in the finishing of the processed surfaces was achieved, and the related mechanisms were identified. The roles of the impact speed and the contact conditions between the abrading particles and the substrate were also investigated.

scholarly journals MATERIAL AND THERMAL ANALYSIS OF LASER SINTERTED PRODUCTS

2013 ◽  
Vol 7 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Radovan Hudák ◽  
Martin Šarik ◽  
Róbert Dadej ◽  
Jozef Živčák ◽  
Daniela Harachová
Keyword(s):  
Thermal Analysis ◽  
Heat Stress ◽  
Thermal Stresses ◽  
Processing Parameters ◽  
Sintering Process ◽  
Input Processing ◽  
Thermal Simulations ◽  
The Impact ◽  
Selection Of

Abstract Thermal analysis of laser processes can be used to predict thermal stresses and consequently deformation in a completed part. Analysis of temperature is also the basic for feedback of laser processing parameters in manufacturing. The quality of laser sintered parts greatly depends on proper selection of the input processing parameters, material properties and support creation. In order to relatively big heat stress in the built part during sintering process, the thermal simulation and thermal analysis, which could help better understand and solve the issue of parts deformations is very important. Main aim of presented work is to prepare input parameters for thermal simulations by the use of RadTherm software (Thermoanalytics Inc., USA), directly during the sintering process and after the process and find out the impact of the heat stress on a final shape and size of the prototype. Subsequently, an annealing process of constructed products after DMLS could be simulated and specified.

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