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The purpose of this paper is to determine the effects of fatigue on fused deposition modeling rapid prototyped acrylonitrile butadiene styrene (ABS) materials.

FDM dog bones based on UNI EN ISO 527‐1 (1997) were tested at 100, 80, 60, and 40 per cent nominal values of the ultimate stress for nine different print orientations. The samples were cyclically stressed in a tensile tester at 25.4 mm/min (extension) and relaxed at 12.7 mm/min.

Although FDM ABS has a tensile strength that is relatively close to that of the bulk material, up to 80 percent, its ability to absorb energy before fracture has a tremendous amount of room for improvement. FDM ABSplus (P430) material properties are noticeably more isotropic than the predecessor, ABS (P400). The ABSplus fractures in the order of thousands of cycles at 40 percent of ultimate stress load, while the ABS exhibits the similar cycle limits at 60 percent of its ultimate stress load.

FDM ABS parts are limited in fatigue characteristics even though they exhibit similar ultimate stress limits as with bulk materials, warranting further research in improving FDM parts expected to experience cyclical loads.

This paper adds knowledge to the limited fatigue data in literature for FDM ABS. It investigated the load cyclic data of fused deposition modeled ABS through analyzing its cycle‐by‐cycle strain energy, providing another means of identifying the fatigue characteristics of materials.

The petroleum industry has been quick to appreciate the possibilities of plastics pipe for handling corrosive fluids and gases, and is now using it in considerable quantities for a variety of applications, including the carrying of corrosive chemicals in refinery and petrochemical plant. From a research engineer in America comes the article below reviewing the main types of pipe materials available for such purposes, special attention being paid to the suitability of their properties for specific types of applications. Also included are hints regarding the installation of pipework.

This paper aims to develop a customized orthosis for treating congenital talipes equinovarus (clubfoot) deformity. Complications from non-surgical treatment method such as Ponseti method leads to relapse/recurrence of the foot after treated.

An alternate approach for treating clubfoot deformity can be seen as a viable approach to overcome the above-mentioned difficulties. Customized orthosis is designed and developed for a subject affected with right clubfoot deformity through fused deposition modeling of additive manufacturing (AM) technology with ABS plastic as base material. A unique mechanism is used to develop customized orthosis for achieving rotation of the foot along the three axis and range of motions.

Developed orthosis is incorporated with a unique mechanism that can be rotated and arrested at the specified angle along the three principle ranges of motion of the foot. Overall weight of the developed customized orthosis achieved is about 284 g, which has a significant 25 per cent reduction in weight when compared to traditional Ponseti casting method. Overcoming the difficulties faced in Ponseti method, customized orthosis can be an alternative method for treating clubfoot.

Developed orthosis will be an alternative approach for treating clubfoot deformity, and it overcomes the drawbacks faced by Ponseti method.

The main purpose of the study was mechanical designing, simulation and manufacturing process for a new model of octocopter V-frame and to achieve simple manufacturing with 3D printing technology. Moreover, the octocopter PID controller was simulated on the Simulink environment to get performance on the roll and pitch angle control.

Octocopter is one kind of multirotor vehicle (a rotorcraft with more than two rotors), that has lately gained a lot of attention for both the scientific and commercial spheres. With a greater number of rotors, the multirotor is very maneuverable and robust. Multi-copter makes an important contribution to the technological revolution in the military, industry, transportation, mapping and especially agriculture. Nowadays, we are heading to the four-industrial revolutions as well as the new technological application in the agricultural field such as precision agriculture, mapping and surveillance. Due to recently advanced technology about sensors, electronics, 3D printing, battery with high performance, multi-copter can be manufactured at low cost.

The V-frame octocopter was chosen to design in this paper; it had better performance scores including high redundancy rotors, high payload capability and affordable cost than another multi-copter family. The V-frame octocopter increasing freedom field of view of the camera was considered to place the camera position in the front of the drone.

For the future aspects, the mechanical structure of the octocopter could be improved by using more advanced metal 3D printing to produce the aluminum or titan alloy materials for lighter and more rigid compared with ABS material, and finally the assembly to the real test.

The study shows the new platform of the V-frame octocopter kinematics analysis, designed on the CAD software, with some important mechanical parts using FEM analysis to find the highest stress and displacement under high load applied, the result of all connecting the joints 3D printing part is completely safe. Mechanical parts were manufactured by using 3D printing technology and CNC milling. Moreover, the study has shown V-frame octocopter simulation based on Simulink using the second method Ziegler- Nichols to find suitable parameters of the PID controller for roll and pitch angle. Using the block simulation is good for implementing and fast checking the new algorithm when building the new platform of the robot.

This study aims to find the usefulness of the customized surgical osteotomy guide (CSOG) for accurate mandibular tumor resection for boosting the accuracy of prefabricated customized implant fixation in mandibular reconstructions.

In all, 30 diseased mandibular RP models (biomodels) were allocated for the study (for experimental group [n = 15] and for control group [n = 15]). To reconstruct the mandible with customized implant in the experimental group, CSOGs and in control group, no CSOG were used for accurate tumor resections. In control group, only preoperative virtual surgical planning (VSP) and reconstructed RP mandible model were used for the reference. Individually each patient’s preoperative mandibular reconstructions data of both the groups were superimposed to the preoperative VSP of respective patient by registering images with the non-surgical side of the mandible. In both the groups, 3D measurements were taken on the reconstructed side and compared the preoperative VSP and postoperative reconstructed mandible data. The sum of the differences between pre and postoperative data was considered as the total error. This procedure was followed for both the groups and compared the obtained error between the two groups using statistical analysis.

The use of CSOG for accurate tumor resection and exact implant fixation in mandibular reconstruction produced a smaller total error than without using CSOG.

The results showed that, benefits provided with the use of CSOG in mandibular reconstruction justified its use over the without using CSOG, even in free hand tumor resection using rotating burr.

Environmental degradation has emerged as one of the major limitations of industrial revolution and has led to an increased focus towards developing sustainable strategies and techniques. This paper aims to highlight the sustainability aspects of three-dimensional (3D) printing technology that helps towards a better implementation of Industry 4.0. It also aims to provide a brief picture of relationships between 3D printing, Industry 4.0 and sustainability. The major goal is to facilitate the researchers, scholars, engineers and recommend further research, development and innovations in the field.

The various enabling factors for implementation of Industry 4.0 are discussed in detail. Some barriers to incorporation of 3D Printing, its applications areas and global market scenario are also discussed. A through literature review has been done to study the detailed relationships between 3D printing, Industry 4.0 and sustainability.

The technological benefits of 3D printing are many such as weight savings, waste minimization and energy savings. Further, the production of new 3D printable materials with improved features helps in reducing the wastage of material during the process. 3D printing if used at a large scale would help industries to implement the concept of Industry 4.0.

This paper focuses on discussing technological revolution under Industry 4.0 and incorporates 3D printing-type technologies that largely change the product manufacturing scenario. The interrelationships between 3D printing, Industry 4.0 and sustainability have been discussed.

In the 1930s, chlorofluorocarbons (CFCs) were developed as safe, non-reactive alternatives to toxic and explosive refrigerants and propellants such as ammonia, chloromethane, and sulfur dioxide. American engineer Thomas Midgley famously demonstrated these properties by inhaling Freon (CFC-12) and blowing out a candle with it. He was presented with many awards for his discoveries, such as the Perkin, Priestley, and William Gibbs medals. In today's jargon, CFCs might have been called an eco-innovation, because they provided solutions to several environmental issues. However, CFCs solved environmental problems by creating others. In 1974, Sherwood Rowland and Mario Molina published their pathbreaking research that demonstrated CFCs were depleting the ozone layer. In 1989, the Montreal Protocol, which regulates a global phaseout of CFCs, entered into force. A few years later, in 1995, Rowland and Molina received the Nobel Price in Chemistry. The new substitutes for CFCs, hydrofluorocarbons (HFCs), have no known effects on the ozone layer but are extremely potent greenhouse gases (GHGs) and thus subject to the Kyoto Protocol.

The democratization of invention is a long lasting desire for the advancement of society. Having access to education and the means of production appears as the major factors for the implementation of this goal. 3D printing is a revolutionary technology that has the potential to bring digital manufacturing to everyone. However, the rise of personal fabrication requires an increase in printing quality, a reduction on machine cost and an increase in knowledge shared by the open hardware community. The purpose of this paper is to explore the development of a new Open Hardware printer project to address these points.

The authors have designed and constructed a low-cost photopolymer-based 3D printer called BeamMaker. The printer is connected to a host computer and a digital-light-processing projector. This work details the design process and how improvements were implemented to reach good printing quality. The authors provide public access to the instructions, software, source code, parts list, user manual and STL and CAD files.

The BeamMaker printer can build objects with a high surface quality that is comparable to the quality obtained by industrial photopolymer-based 3D printers. When testing the ability to print a sample cylinder, the printer shows higher accuracy when compared to other personal 3D printers. These findings are encouraging considering the low cost of the system.

The printing failure rate of the system has not been measured to date. The system requires some improvements to produce large objects.

The printer cost is just USD380. This is five to eight times less expensive than popular personal 3D printers available today. The cost is 30 times less expensive than a personal photopolymer 3D printer produced by a main commercial company and yet producing results of similar quality. The authors expect good avenues for collaboration from the open-source community to continue improving these systems.

The high cost of current personal 3D printers prevents users from developing countries from entering into the open hardware trend. A dramatic reduction in printer cost such as that explored in this work might contribute to the real democratization of personal fabrication.

The authors report on the status of three other photopolymer-based personal 3D printer projects. To the best of the authors' knowledge, BeamMaker is the first fully open hardware 3D printer project which uses this technology.

After experimental testing, it was recognized that a component’s strength relationship with respect to the volume material usage is inconsistent and that failures occurred in regions of voids. The purpose of this study is to present an optimal toolpath for a material extrusion process to minimize voids and discontinuities using standard parameters and settings available for any given machine.

To carry out this study, a literature review was performed to understand the influence of the build parameters. Then, an analysis of valid parameter settings to be targeted was performed for a commercial system. Fortus 400 machine build parameters are used for the case studies presented here. Optimal relationships are established based on the geometry and are to be applied on a layer-by-layer or sub-region basis and available machine build options. The component geometry is analyzed and decomposed into build regions. Matlab® is used to determine a standard (available) toolpath parameters with optimal variables (bead height, bead width, raster angle and the airgap) for each layer/build region.

It was found that the unwanted voids are decreased by up to 8 per cent with the new model. The final component will contain multiple bead widths and overlap conditions, but all are feasible as the available machine solutions are used to seed the model.

Unwanted voids can create failure points. Introducing an optimization solution for a maximized material fill strategy using existing build options will reduce the presence of voids and will eliminate “chimneys” or a void present in every layer of the component. This solution can be implemented using existing machine-toolpath solutions.

This study demonstrates that existing build settings and toolpath strategies can be used to improve the interior fill by performing targeted optimization strategies for the build parameters.

Understanding how material jetting process parameters affect material properties can inform design and print orientation when manufacturing end-use components. This study aims to explore the robustness of material properties in material jetted components to variations in processing environment and build orientation.

The authors characterized the properties of six different material gradients produced from preset “digital material” mixes of polypropylene-like (VeroWhitePlus) and elastomer-like (TangoBlackPlus) materials. Tensile stress, modulus of elasticity and elongation at break were analyzed for each material printed at three different build orientations. In a separate ten-week study, the authors investigated the effects of aging in different lighting conditions on material properties.

Specimens fabricated with their longest dimension along the direction of the print head travel (X-axis) tended to have the largest tensile strength, but trends in elastic modulus and elongation at break varied between the rigid and flexible photopolymers. The aging study showed that the ultimate tensile stress of VeroWhitePlus parts increased and the elongation decreased over time. Material properties were not significantly altered by lighting conditions.

Many tensile specimens failed at the neck region, especially for the more elastomeric parts. It is hypothesized that this is due to the material jetting process approximating curves with a pixelated droplet arrangement, instead of curved contour as seen in other additive manufacturing processes. A new tensile specimen design that performs more consistently with elastomer-like materials should be considered. The aging component of this study is focused solely on polypropylene-like (VeroWhitePlus) material; additional research into the effects of aging on multiple composite materials is needed.

The study provides the first known description of orientation effects on the mechanical behavior of photopolymers containing varied concentrations of elastomeric (TangoBlackPlus) material. The aging study presents the first findings on how time affects parts made via material jetting.