Assessment of a Virtual Functional Prototyping Process for the Rapid Manufacture of Passive-Dynamic Ankle-Foot Orthoses

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Elisa S. Schrank ◽  
Lester Hitch ◽  
Kevin Wallace ◽  
Richard Moore ◽  
Steven J. Stanhope
Keyword(s):  
Elastic Modulus ◽  
Computer Aided Design ◽  
Prediction Accuracy ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Bending Stiffness ◽  
Cad Model ◽  
Functional Characteristics ◽  
Element Analysis ◽  
Fused Deposition

Passive-dynamic ankle-foot orthosis (PD-AFO) bending stiffness is a key functional characteristic for achieving enhanced gait function. However, current orthosis customization methods inhibit objective premanufacture tuning of the PD-AFO bending stiffness, making optimization of orthosis function challenging. We have developed a novel virtual functional prototyping (VFP) process, which harnesses the strengths of computer aided design (CAD) model parameterization and finite element analysis, to quantitatively tune and predict the functional characteristics of a PD-AFO, which is rapidly manufactured via fused deposition modeling (FDM). The purpose of this study was to assess the VFP process for PD-AFO bending stiffness. A PD-AFO CAD model was customized for a healthy subject and tuned to four bending stiffness values via VFP. Two sets of each tuned model were fabricated via FDM using medical-grade polycarbonate (PC-ISO). Dimensional accuracy of the fabricated orthoses was excellent (average 0.51 ± 0.39 mm). Manufacturing precision ranged from 0.0 to 0.74 Nm/deg (average 0.30 ± 0.36 Nm/deg). Bending stiffness prediction accuracy was within 1 Nm/deg using the manufacturer provided PC-ISO elastic modulus (average 0.48 ± 0.35 Nm/deg). Using an experimentally derived PC-ISO elastic modulus improved the optimized bending stiffness prediction accuracy (average 0.29 ± 0.57 Nm/deg). Robustness of the derived modulus was tested by carrying out the VFP process for a disparate subject, tuning the PD-AFO model to five bending stiffness values. For this disparate subject, bending stiffness prediction accuracy was strong (average 0.20 ± 0.14 Nm/deg). Overall, the VFP process had excellent dimensional accuracy, good manufacturing precision, and strong prediction accuracy with the derived modulus. Implementing VFP as part of our PD-AFO customization and manufacturing framework, which also includes fit customization, provides a novel and powerful method to predictably tune and precisely manufacture orthoses with objectively customized fit and functional characteristics.

scholarly journals The Effects of Combined Infill Patterns on Mechanical Properties in FDM Process

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2792
Author(s):  
Mohammadreza Lalegani Dezaki ◽  
Mohd Khairol Anuar Mohd Ariffin
Keyword(s):  
Mechanical Properties ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Strength Analysis ◽  
Element Analysis ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
3D Printed ◽  
Complex Features ◽  
Aided Design

Fused deposition modeling (FDM) is commonly used to print different products with highly complex features. Process parameters for FDM are divided into controllable or uncontrollable parameters. The most critical ones are built orientation, layer thickness, infill pattern, infill density, and nozzle diameter. This study investigates the effects of combined infill patterns in 3D printed products. Five patterns (solid, honeycomb, wiggle, grid, and rectilinear) were combined in samples to analyze their effects on mechanical properties for tensile strength analysis. Polylactic acid (PLA) samples were printed in different build orientations through two directions: flat and on-edge. The limitation was that the software and machine could not combine the infill patterns. Thus, the patterns were designed and assembled in computer aided design (CAD) software. Finite element analysis (FEA) was used to determine the patterns’ features and results showed honeycomb and grid have the highest strength while their weights were lighter compared to solid. Moreover, 0° samples in both flat and on-edge direction had the strongest layer adhesion and the best quality. In contrast, perpendicular samples like 60° and 75° showed poor adhesion and were the weakest specimens in both flat and on-edge, respectively. In brief, by increasing the build orientation, the strength decreases in this study.

Observation of Shape and Dimensional Accuracy Changing of Parts in Time Intervals Manufactured by Additive Method Fused Deposition Modeling

2018 ◽  
Vol 919 ◽  
pp. 182-189
Author(s):  
Ivan Molnár ◽  
Róbert Hrušecký ◽  
Ladislav Morovič ◽  
Augustín Görög
Keyword(s):  
Fused Deposition Modeling ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Medical Applications ◽  
Cad Model ◽  
Time Intervals ◽  
Manufacturing Method ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Measuring Machine

This article deals with the observation of shape and dimensional accuracy of parts after manufacturing in certain time intervals. The parts was manufactured by additive manufacturing method Fused Deposition Modeling (FDM). The shape and chosen dimension changes due to material shrinkage was observed on materials, namely Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol (PET-G). These materials rank among health-conscious and usable in some medical applications. The parts were measured by using coordinate measuring machine (CMM) in certain time intervals and the shape and chosen dimensions was compared with the reference computer aided designed (CAD) model.

Modeling Machine Motion and Process Parameter Errors for Improving Dimensional Accuracy of Fused Deposition Modeling Machines

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Jiaqi Lyu ◽  
Souran Manoochehri
Keyword(s):  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Error Model ◽  
Fused Deposition ◽  
Model Combining ◽  
Before And After ◽  
Deposition Modeling ◽  
Integrated Error

The dimensional accuracy of fused deposition modeling (FDM) machines is dependent on errors caused by processing parameters and machine motions. In this study, an integrated error model combining these effects is developed. Extruder temperature, layer thickness, and infill density are selected as parameters of this study for three FDM machines, namely, Flashforge Finder, Ultimaker 2 go, and XYZ da Vinci 2.0 Duo. Experiments have been conducted using Taguchi method and the interactions between processing parameters are analyzed. Based on the dimensional deviations between fabricated parts and the computer aided design (CAD) geometry, a set of coefficients for the integrated error model are calculated to characterize each machine. Based on the results of the integrated error model, the original CAD geometry is optimized for fabrication accuracy on each machine. New parts are fabricated using the optimized CAD geometries. Through comparing the dimensional deviations of parts fabricated before and after optimization, the effectiveness of the integrated error model is analyzed and demonstrated for the three FDM machines.

Comparative evaluation of an open-source FDM system

2014 ◽  
Vol 20 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Wayne M. Johnson ◽  
Matthew Rowell ◽  
Bill Deason ◽  
Malik Eubanks
Keyword(s):  
Open Source ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Fused Deposition Modeling ◽  
Low Cost ◽  
Dimensional Accuracy ◽  
Scanning System ◽  
Content Type ◽  
Geometric Dimensioning And Tolerancing ◽  
Fused Deposition

Purpose – The purpose of this paper is to present a qualitative and quantitative comparison and evaluation of an open-source fused deposition modeling (FDM) additive manufacturing (AM) system with a proprietary FDM AM system based on the fabrication of a custom benchmarking model. Design/methodology/approach – A custom benchmarking model was fabricated using the two AM systems and evaluated qualitatively and quantitatively. The fabricated models were visually inspected and scanned using a 3D laser scanning system to examine their dimensional accuracy and geometric dimensioning and tolerancing (GD&T) performance with respect to the computer-aided design (CAD) model geometry. Findings – The open-source FDM AM system (CupCake CNC) successfully fabricated most of the features on the benchmark, but the model did suffer from greater thermal warping and surface roughness, and limitations in the fabrication of overhang structures compared to the model fabricated by the proprietary AM system. Overall, the CupCake CNC provides a relatively accurate, low-cost alternative to more expensive proprietary FDM AM systems. Research limitations/implications – This work is limited in the sample size used for the evaluation. Practical implications – This work will provide the public and research AM communities with an improved understanding of the performance and capabilities of an open-source AM system. It may also lead to increased use of open-source systems as research testbeds for the continued improvement of current AM processes, and the development of new AM system designs and processes. Originality/value – This study is one of the first comparative evaluations of an open-source AM with a proprietary AM system.

Fabrication and Design of Customized Maxillofacial Biomodel for Implant Using Computer Aided Design and Rapid Prototyping Technique

2013 ◽  
Vol 391 ◽  
pp. 406-409 ◽  
Author(s):  
Wan Yusoff Way ◽  
M. Aichouni ◽  
M. Zul Amzar Zulkiflee ◽  
Mohd Sallehuddin Ahmad Derifaee
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Design Technology ◽  
Fused Deposition ◽  
Computer Aided ◽  
Analysis Computer ◽  
Operational Error ◽  
Aided Design

The purpose of this research is to fabricate bio-model that based on Rapid Prototyping technology which is by using Fused Deposition Modeling (FDM) and designing an implant by using a Computer Aided Design technology. A case study from Hospital Kuala Lumpur which is the maxillofacial will be fabricated by using FDM technique. The completed 3D prototype or biomodel will be analyzed to makes the result more truthful in terms of the dimensional accuracy, operational error and cost analysis. Computer aided design technology is used to design the customized implant in order to replace the fractured maxilla part.

scholarly journals Influence of Infill Patterns Generated by CAD and FDM 3D Printer on Surface Roughness and Tensile Strength Properties

2021 ◽  
Vol 11 (16) ◽  
pp. 7272
Author(s):  
Mohammadreza Lalegani Dezaki ◽  
Mohd Khairol Anuar Mohd Ariffin ◽  
Ahmad Serjouei ◽  
Ali Zolfagharian ◽  
Saghi Hatami ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Strength Analysis ◽  
Element Analysis ◽  
Fused Deposition ◽  
Dog Bone ◽  
Wide Range

Fused deposition modeling (FDM) is a capable technology based on a wide range of parameters. The goal of this study is to make a comparison between infill pattern and infill density generated by computer-aided design (CAD) and FDM. Grid, triangle, zigzag, and concentric patterns with various densities following the same structure of the FDM machine were designed by CAD software (CATIA V5®). Polylactic acid (PLA) material was assigned for both procedures. Surface roughness (SR) and tensile strength analysis were conducted to examine their effects on dog-bone samples. Also, a finite element analysis (FEA) was done on CAD specimens to find out the differences between printing and simulation processes. Results illustrated that CAD specimens had a better surface texture compared to the FDM machine while tensile tests showed patterns generated by FDM were stronger in terms of strength and stiffness. In this study, samples with concentric patterns had the lowest average SR (Ra) while zigzag was the worst with the value of 6.27 µm. Also, the highest strength was obtained for concentric and grid samples in both CAD and FDM procedures. These techniques can be useful in producing highly complex sandwich structures, bone scaffolds, and various combined patterns to achieve an optimal condition.

scholarly journals Some Investigations on Geometric Conformity Analysis of a 3-D Freeform Objects Produced by Rapid Prototyping (FDM) Process

2012 ◽  
pp. 201-205
Author(s):  
V. Vinod Kumar ◽  
G. R. N. Tagore ◽  
A. Venugopal
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Cad Model ◽  
Fused Deposition ◽  
Computer Aided ◽  
Deposition Modeling ◽  
Geometric Deviation ◽  
Aided Design ◽  
Computer Aided Inspection

Rapid prototyping technology is widely used to fabricate 3-D objects with all features of a design using Computer Aided Design (CAD) model. The final fabricated object with rapid prototyping technique has to be evaluated regarding the extent of its closeness to CAD model. Geometric conformity analysis has to be used in determining a measure of the geometric deviation between designed and fabricated 3-D models. In this paper evaluation technique is used to provide an aggregate measure of overall geometric deviation between designed free formed surface and its fabricated geometries using Fused Deposition Modeling (FDM) technique. This approach is typically utilized for large or more complex assemblies such as vehicle interiors and exteriors and full scale aircraft etc. Computer Aided Inspection with CMM aims at development of suitable methodology so as to convert data obtained from CMM to convenient formats to measure dimensional and form errors of freeform surface objects. The present work used in additive manufacturing with the newer methodology of inspecting in rapid product development also.

scholarly journals Design and development of open source portable multi-functional three-dimensional bio-printing extrusion system for hydrogel-based scaffolds fabrication

2021 ◽  
Author(s):  
Pouya Behrouzi ◽  
Mahmood Zali ◽  
Mahdi Muhaddesi ◽  
Alireza Hashemi ◽  
Arezoo Khoradmehr ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Thermal Control ◽  
Numerical Control ◽  
Cnc Machine ◽  
Design And Development ◽  
Element Analysis ◽  
3D Print ◽  
Fused Deposition

Abstract Three-dimensional (3D) bio-printing has been shown up as a state of the art and creative technological solution to nowadays tissue engineering and stem cell research challenges toward human tissue regeneration and construction of artificial living organs. Thereby, using hydrogel-based bio-inks to 3D print living microenvironments is a crucial strategy to reconstruct basically functional living scaffolds in order to shape human living organs based on digital 3D computer-aided design (CAD) inputs. The focus of this paper lies on design and development of a portable multi-functional 3D bio-printing extruder for fabrication of hydrogel-based highly complex living tissues using advanced methods invented along this study. The presented article, precisely optimizes the process of fabricating 3D printed scaffolds by redesigning of an integrated gel-extrusion system capable of controlling the adjustability of thermal condition of bio-inks. Also a UV crosslink module is utilized in the bottom of the extruder to cure hydrogel scaffolds consisting of photo-reacting agents to provide a novel bio-printing experience for end users. As a result, the integrated extrusion system is easily portable and compatible with almost any computer numerical control (CNC) machine. Therefore, it could be simply installed on or removed from any CNC machine or fused deposition modeling (FDM) 3D printing system considering that all the control units remain adjustable. The whole system parameters and the performance of tissue fabrication regarding this developed portable multi-functional 3D bio-printing extruder have been tested and practically confirmed. The thermal control system performance has also been simulated using finite element analysis (FEA) and computational fluid dynamics (CFD) methods. Thus, certified documents have been provided and depicted in this paper.

Reverse Engineering a Hedge Trimmer: A Practical Approach to Incorporate Geometric Dimensioning and Tolerancing (GD&T) Effectively in an Undergraduate Freshman Engineering Course

2020 ◽  
Author(s):  
Tikran Kocharian ◽  
Sanjivan Manoharan
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Real Life ◽  
Cad Model ◽  
Geometric Dimensioning And Tolerancing ◽  
Fused Deposition ◽  
Dimensioning And Tolerancing ◽  
Engineering Drawings ◽  
Broad Subject

Abstract Geometric Dimensioning and Tolerancing (GD&T), due to the inherent complexity, is a challenging topic to teach and learn, especially at the undergraduate freshman level. Many institutes either cover GD&T on a superficial level or choose to overlook it. Incorporating such a broad subject in an already busy curricula remains a major challenge for many academic institutes, including ours. The knowledge and skill level of our students in GD&T at the beginning of their co-op is a major concern for several employers. These employers have to expend significant resources to train our students and graduates. To address this growing concern, a practical project was incorporated into a freshman introductory engineering course; a Ryobi hedge trimmer Model No. RY39500 was utilized. The students were divided into five groups, and each group was given a mechanical component from the assembly. First, each group was tasked with taking the necessary measurements to create a Computer Aided Design (CAD) model of their component in an effort to commence the reverse engineering process. The CAD model was then additively manufactured using fused deposition modeling. A detailed drawing of each component was created and GD&T concepts and symbols were applied to the drawing following ASME/ANSI Y14.5-2009 standards. The project was very well received by the students. It enhanced their understanding and skills necessary to implement GD&T concepts and symbols both in practice and in preparing engineering drawings. The 3-D printed parts were shared among the groups and the manufactured parts were fit together to replicate the real life assembling.

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