scholarly journals Evaluation of Additive Manufacturing Processes in Fabrication of Personalized Robot

2017 ◽  
Vol 11 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Shushu Wang ◽  
◽  
Rakshith Badarinath ◽  
El-Amine Lehtihet ◽  
Vittaldas Prabhu

Customer participation in the design stage of creating personalized products is increasing. Additive manufacturing (AM) has become a popular enabler of personalization. In this study, we evaluate the fabrication of an open-source robot arm in terms of cost, build time, dimensional and locational accuracy, end-effector accuracy, and mechanical properties. The mechanical components of the table-top robot were fabricated using two different AM processes of fused deposition modeling (FDM) and material jetting (polymer jetting or PolyJet). A reduction of infill density by 50% in the FDM process slightly decreased the building time, material cost, and tensile strength, but induced a 95% reduction in yield strength. A simulation of the mechanical assembly using the CAD models for the robot and the expected tolerances of the components estimated the end-effector positioning accuracy as 0.01–0.22 mm. The 3D printed robot arm was redesigned and fabricated using the best evaluated process in this study.

Author(s):  
Renkai Huang ◽  
Ning Dai ◽  
Dawei Li ◽  
Xiaosheng Cheng ◽  
Hao Liu ◽  
...  

Surface finish, especially the surface finish of functional features, and build time are two important concerns in additive manufacturing. A suitable part deposition orientation can enhance the surface quality of functional features and reduce the build time. This article proposes a novel method to obtain an optimum part deposition orientation for industrial-grade 3D printing based on fused deposition modeling process by considering two objective functions at a time, namely adaptive feature roughness (the weighted sum of all feature roughnesses) and build time. First, mesh segmentation and level classification of features are carried out. Then, models for evaluation of adaptive feature roughness and build time are established. Finally, a non-dominated sorting genetic algorithm-II based on Compute Unified Device Architecture is used to obtain the Pareto-optimal set. The feasible of the algorithm is evaluated on several examples. Results demonstrate that the proposed parallel algorithm obtains a limiting solution that enhances the surface quality of functional features significantly and reduces average running time by 94.8% compared with the traditional genetic algorithm.


2017 ◽  
Vol 887 ◽  
pp. 128-132 ◽  
Author(s):  
Shaheryar Atta Khan ◽  
Bilal Ahmed Siddiqui ◽  
Muhammad Fahad ◽  
Maqsood Ahmed Khan

Additive manufacturing has stepped down from the world of Sci-Fi into reality. Since its conception in the 1980s the technology has come a long way. May variants of the technology are now available to the consumer. With the advent of custom built (open source) Fused Deposition Modeling based printing technology Fused Filament Fabrication (FFF), FDM/FFF has become the most used Additive Manufacturing technology. The effects of the different infill patterns of FDM/FFF on the mechanical properties of a specimen made from ABS are studied in this paper. It is shown that due to changes in internal structures, the tensile strength of the specimen changes. The study also investigate the effect of infill pattern on the build time of the specimen. Extensive testing yielded the optimal infill pattern for FDM/FFF. An open source Arduino based RepRap printer was used for the preparation of specimen and showed promising results for rapid prototyping of custom built parts to bear high loads. The study can help with the increase in the use of additive manufacturing for the manufacturing of mechanically functioning parts such as prosthetics


Author(s):  
Ismayuzri Bin Ishak ◽  
Joseph Fisher ◽  
Pierre Larochelle

This article discusses the concept of using an industrial robot arm platform for additive manufacturing. The concept being explored is the integration of existing additive manufacturing process technologies with an industrial robot arm to create a 3D printer with a multi-plane layering capability. The objective is to develop multi-plane toolpath motions that will leverage the increased capability of the robot arm platform compared to conventional gantry-style 3D printers. This approach enables print layering in multiple planes whereas existing conventional 3D printers are restricted to a single toolpath plane (e.g. x-y plane). This integration combines the fused deposition modeling techniques using an extruder head that is typically used in 3D printing and a 6 degree of freedom robot arm. Here, a Motoman SV3X is used as the platform for the robot arm. A higher level controller is used to control the robot and the extruder. To communicate with the robot, MotoCom SDK libraries is used to develop the interfacing software between the higher level controller and the robot arm controller. The integration of these systems enabled multi-plane toolpath motions to be utilized to produce 3D printed parts. A test block has been 3D printed using this integrated system.


Author(s):  
Sungshik Yim ◽  
David Rosen

Due to the varieties of available Additive Manufacturing (AM) technologies, it is challenging to select appropriate processes to cost effectively build a part, especially when a user does not have in-depth knowledge about AM. In this paper, we introduce approximate models of build time and cost for AM processes that can be used for early stage process selection. Therefore, a user can identify and compare candidate manufacturing processes based on build time and cost estimates that are computed from approximate geometric information about the part, specifically the part’s bounding box and its estimated volume. The build time model is based on a generalized parameterization of AM processes that applies to laser-based scanning (Stereolithography, powder bed fusion), filament extrusion (fused-deposition modeling), ink-jet printing, and mask-projection processes. Build time estimates were tested by comparing them to the measured build time of parts in fabricated using Stereolithography, ink-jet printing, and fused deposition modeling processes.


2019 ◽  
Vol 799 ◽  
pp. 276-281
Author(s):  
Ramisha Sajjad ◽  
Sajid Ullah Butt ◽  
Khalid Mahmood ◽  
Hasan Aftab Saeed

Additive Manufacturing is a manufacturing process based on layers for making three dimensional scaled physical parts directly from 3D CAD data. Fused Deposition Modeling (FDM) is widely used technology that provides functional prototypes in various thermoplastics. In additive manufacturing, filling patterns are of two types; External and Internal filling patterns. Multiple patterns are developed for both filling categories. In this work, a heterogeneous infill strategy is used by choosing developed patterns in order to improve strength to weight ratio, material usage and build time for parts. A rectilinear pattern combination with triangular and rectangular pattern has been chosen for 3D printing. The tensile testing is performed on the printed specimens to calculate the strength to weight ratio. By comparing the obtained results, a strategy based on maximum strength to weight ratio, minimum material usage and reduced build time is recommended for FDM technology.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zahra Faraji Rad ◽  
Philip D. Prewett ◽  
Graham J. Davies

AbstractMicroneedle patches have received much interest in the last two decades as drug/vaccine delivery or fluid sampling systems for diagnostic and monitoring purposes. Microneedles are manufactured using a variety of additive and subtractive micromanufacturing techniques. In the last decade, much attention has been paid to using additive manufacturing techniques in both research and industry, such as 3D printing, fused deposition modeling, inkjet printing, and two-photon polymerization (2PP), with 2PP being the most flexible method for the fabrication of microneedle arrays. 2PP is one of the most versatile and precise additive manufacturing processes, which enables the fabrication of arbitrary three-dimensional (3D) prototypes directly from computer-aided-design (CAD) models with a resolution down to 100 nm. Due to its unprecedented flexibility and high spatial resolution, the use of this technology has been widespread for the fabrication of bio-microdevices and bio-nanodevices such as microneedles and microfluidic devices. This is a pioneering transformative technology that facilitates the fabrication of complex miniaturized structures that cannot be fabricated with established multistep manufacturing methods such as injection molding, photolithography, and etching. Thus, microstructures are designed according to structural and fluid dynamics considerations rather than the manufacturing constraints imposed by methods such as machining or etching processes. This article presents the fundamentals of 2PP and the recent development of microneedle array fabrication through 2PP as a precise and unique method for the manufacture of microstructures, which may overcome the shortcomings of conventional manufacturing processes.


Author(s):  
Arash Alex Mazhari ◽  
Randall Ticknor ◽  
Sean Swei ◽  
Stanley Krzesniak ◽  
Mircea Teodorescu

AbstractThe sensitivity of additive manufacturing (AM) to the variability of feedstock quality, machine calibration, and accuracy drives the need for frequent characterization of fabricated objects for a robust material process. The constant testing is fiscally and logistically intensive, often requiring coupons that are manufactured and tested in independent facilities. As a step toward integrating testing and characterization into the AM process while reducing cost, we propose the automated testing and characterization of AM (ATCAM). ATCAM is configured for fused deposition modeling (FDM) and introduces the concept of dynamic coupons to generate large quantities of basic AM samples. An in situ actuator is printed on the build surface to deploy coupons through impact, which is sensed by a load cell system utilizing machine learning (ML) to correlate AM data. We test ATCAM’s ability to distinguish the quality of three PLA feedstock at differing price points by generating and comparing 3000 dynamic coupons in 10 repetitions of 100 coupon cycles per material. ATCAM correlated the quality of each feedstock and visualized fatigue of in situ actuators over each testing cycle. Three ML algorithms were then compared, with Gradient Boost regression demonstrating a 71% correlation of dynamic coupons to their parent feedstock and provided confidence for the quality of AM data ATCAM generates.


Author(s):  
Alfonso Costas ◽  
Daniel E. Davis ◽  
Yixian Niu ◽  
Sadegh Dabiri ◽  
Jose Garcia ◽  
...  

Additive manufacturing has emerged as an alternative to traditional manufacturing technologies. In particular, industries like fluid power, aviation and robotics have the potential to benefit greatly from this technology, due to the design flexibility, weight reduction and compact size that can be achieved. In this work, the design process and advantages of using 3D printing to make soft linear actuators were studied and highlighted. This work explored the limitations of current additive manufacturing tolerances to fabricate a typical piston-cylinder assembly, and how enclosed bellow actuators could be used to overcome high leakage and friction issues experienced with a piston-cylinder type actuator. To do that, different 3D printing technologies were studied and evaluated (stereolithorgraphy and fused deposition modeling) in the pursuit of high-fidelity, cost-effective 3D printing. The initial attempt consisted of printing the soft actuators directly using flexible materials in a stereolithography-type 3D printer. However, these actuators showed low durability and poor performance. The lack of a reliable resin resulted in the replacement of this material by EcoFlex® 00-30 silicone and the use of a 3D printed mold to cast the actuators. These molds included a 3-D printed dissolvable core inside the cast actuator in order to finish the manufacturing process in one single step. An experimental setup to evaluate the capabilities of these actuators was developed. Results are shown to assess the steady-state and the dynamic characteristics of these actuators. These tests resulted into the stroke-pressure and stroke-time responses for a specific load given different proportional valve inputs.


Author(s):  
Aniruddha V. Shembekar ◽  
Yeo Jung Yoon ◽  
Alec Kanyuck ◽  
Satyandra K. Gupta

Additive manufacturing (AM) technologies have been widely used to fabricate 3D objects quickly and cost-effectively. However, building parts consisting of complex geometries with multiple curvatures can be a challenging process for the traditional AM system whose capability is restricted to planar-layered printing. Using 6-DOF industrial robots for AM overcomes this limitation by allowing materials to deposit on non-planar surfaces with desired tool orientation. In this paper, we present collision-free trajectory planning for printing using non-planar deposition. Trajectory parameters subject to surface curvature are properly controlled to avoid any collision with printing surface. We have implemented our approach by using a 6-DOF robot arm. The complex 3D structures with various curvatures were successfully fabricated, while avoiding any failures in joint movement, holding comparable build time and completing with a satisfactory surface finish.


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