Computer-aided Manufacturing Software Research Articles

Impact of smoothing interpolations on the non-conventional machining of pockets

Smoothing curves have been used in computer aided design software for years. This is the reason why machinists very early wondered about the possibilities of creating toolpaths directly generated from this type of mathematical curves. In addition, in recent research work, we have shown that the non-uniform rational Bspline interpolation is the most favorable towards high-speed machining of complex shapes. As a result, we are thinking of simulating by this type of interpolation the pocket recess machining strategies proposed by a computer aided manufacturing software, currently developed in linear and circular interpolations only. In this article we propose a study of the influence of the parameters of Bspline curves on the hollowing out of pockets by smoothing initial cutting methods. To do this, we chose the smoothing of the zigzag method by Bspline and NURBS while varying the order and the discretization parameters to know the impact on the dynamics of the high-speed machining mechanism and on the non-conventional machining precision. This work has shown that parametric curves are favored for this type of machining provided that this tool is mastered.

Feasibility of 8-Shaped Motion Test for Five-Axis Machining Center

ISO 10791-7, which specifies the machining accuracy test standard for machining centers, and ISO 10791-6, which specifies the interpolation motion test standard, were revised in 2014 to include five-axis machining centers (5-axis MCs). In addition, cone frustum test, which has been used as the National Aerospace Standard (NAS), was revised and introduced in these ISO standards. However, prior to the establishment of these standards, an aircraft manufacturing company in China proposed S-shaped machining test to measure the accuracy of the test piece of an aircraft. This was adopted as an informative annex of ISO 10791-7 in 2020. Furthermore, in 2019, China proposed a method related to S-shaped machining test and a method of 8-shaped interpolation motion test. Since the S-shaped test requires high acceleration and deceleration in some sections, the test results depend on the performance of the computer-aided manufacturing (CAM) software; therefore, it is not efficient in determining the accuracy of the machine tools. In contrast, in the 8-shaped motion test, the tip of the spindle moves based on a sine curve; consequently, high acceleration/deceleration does not occur. Since the tip of the cutting tool is fixed, a device called R-test is used to measure the position of the center of reference ball using three displacement sensors. In this study, we have discussed the feasibility and problems of the 8-shaped motion test. First, the motion of the machine in the figure “8” motion test is clarified. Next, the definition of the parameters necessary to create the NC programs is outlined. In addition, we have proposed a method in which suitable conditions are set for simultaneous 5-axis feed on a 5-axis MC. Finally, the results of an actual test are applied to the 5-axis MC to confirm that no major problems exist.

Clinical evaluation of the agreement between virtual and clinical occlusal registrations: A comparative clinical study

The accuracy of virtual interocclusal records has been evaluated, but clinical studies comparing the clinical output to the virtual design are lacking. The purpose of this clinical study was to evaluate the agreement between the virtual occlusal scheme designed by a computer-aided design and computer-aided manufacturing software program and the occlusal scheme obtained clinically on the definitive prosthesis assessed with articulating paper. The virtual occlusal scheme design of 20 single monolithic crowns and their adjacent teeth was obtained by using an intraoral scanning system in 17 participants. These registrations were compared with conventional occlusal records obtained by applying articulating paper in 2 stages: first with 200-μm blue film and the second with 12-μm metallic red articulation tape. The analysis included both the quantity and the quality of the contacts of the conventional occlusal records referred to as the standard method. For accuracy analysis, virtual record sensitivity was calculated per crown as the percentage of true positive virtual contacts of the actual contacts identified by articulating paper. Specificity was also calculated as the percentage of true negative virtual contacts of the actual sites of clearance. The virtual record sensitivity was 98.5 (95% confidence interval [CI] 96-100) for the crowns and 95 (95% CI 85-100) for the adjacent teeth. The virtual record specificity was 88.6 (95% CI 82.4-94.8) for the crowns and 82.6 (95% CI 77.5-87.6) for the adjacent teeth. The agreement between the clinical and virtual contact intensities on the crowns was 83 (95% CI 73-93) and 67.3 (95% CI 56-78.7) for the adjacent teeth. The positive predictive value was 72.83 (95% CI 60-86). The negative predictive value was 100% (95% CI 100-100). The intraoral scanning system provided clinically sufficient sensitivity and specificity for identifying the occlusal surface contacts of monolithic crowns. A slight decrease was detected in the system's sensitivity and specificity in identifying contacts on adjacent teeth and a larger decrease identifying the intensity of these contacts.

A hybrid framework for manufacturing feature recognition from CAD models of 3-axis milling parts

With the rapid development of computing technologies, the CAX software are widely used in mechanical engineering. The part model is designed in computer-aided design (CAD) software, the planning process is planned in computer-aided process planning (CAPP) software, and the machining process is simulated in computer-aided manufacturing (CAM) software. However, there are still digital gaps between design, process, and manufacturing, which affect the integration and efficiency of engineering information. Manufacturing features are considered digital carriers that can bridge the gap. The knowledge of design, process, and manufacturing can be integrated on manufacturing features to achieve the information flow across different engineering applications. However, the existing approaches cannot solve the feature recognition problem very well. The recognition criterion of these approaches do not have the generalization ability. And they also do not deal with the interacting features appropriately. To improve the performance of feature recognition of 3-axis milling parts, this paper proposed a hybrid feature recognition framework based on graph approach and rule approach. The hybrid framework solves the recognition problem of interacting features with the layered decomposition method. And the general wire criterion is proposed to improve the robustness. In addition, the general calculation method of adjacency attributes is also the original contribution. The final experimental results show that the proposed hybrid framework works well and can be applied to the actual engineering applications.

Modified tool radius compensation in the Archimedes' spiral tool path for high speed machining of circular geometry

A key role in HSM (High Speed Machining) is played by the NC program code, which guides the tool along a programmed path without jumps in velocity and acceleration. The commonly used CAM (Computer Aided Manufacturing) software offers many operations for dynamic machining, but the generated code is difficult to edit. An alternative is to use parameterized technology cycles. Unfortunately, the circular pocket cycle available on the Siemens Sinumerik 840D controller was not designed for HSM machining. The purpose of the article is to program an Archimedes' spiral using modified tool radius compensation. The parametric NC code was implemented on the Siemens Sinumerik 840D controller as a technology cycle. The obtained trajectory of the tool meets the curvature continuity condition (C2 continuity). The algorithm uses 3 NC program blocks to define the spiral, regardless of its length. Tool positions are calculated directly by the interpolator during the tool's circular motion (G2/G3). Spiral step is achieved by an additional contour offset (OFFN function), and also by multiple repetitions of circles (TURN function). The change in the effective tool radius value during active tool radius compensation (G41/G42) moves the tool away from the contour along the length of the entire NC block. Several spiral programming variants that are used in cycles were analyzed to identify the feed rate drops at joining points between program blocks. During the process, the trajectory and feed rate were recorded using the Sinumerik Trace function. A problem with the Siemens Sinumerik controller was identified when machine axes exceed the acceleration limit. Synchronized actions were implemented to reduce the feed rate, with the acceleration and jerk limit that are specified in the part program being taken into account. The presented cycle, with the graphical user interface, highlights the potential for HSM milling. The conducted experiment shows the need to supplement the Siemens Sinumerik controller with Archimedes' spiral interpolation. New technology cycles will increase productivity and open up new possibilities, such as tapered threads milling.

Innovative process for precise grinding of optical free-form elements

The aim of the presented article is to share experience gained throughout the course of two projects focused on precise grinding of a free-form glass optical element with the objective of achieving a surface shape error of less than approximately 10 μm PV before the subsequent polishing phases. Compared to spheres or aspheres machining, it is considerably more demanding, mainly due to the impossibility of using rotationally symmetric shape corrections. The developed and tested process combines a mechanical engineering approach based on the use of the current Computer Aided Design and Computer Aided Manufacturing software with their respective strengths and weaknesses and an optical engineering approach, for which the employment of CNC machines featuring precise control but low flexibility is typical. Therefore, attention is paid mainly to the description of particular process steps like CAD construction and CNC grinding step programming with regard to the necessary software and data handling, as well as the required parametrisation of the used machine equipment.

Evaluation of Novel Device "Obturagun" as a Root Canal Obturating Technique for Primary Teeth: An In Vitro Study.

Pulpectomy is one of the most commonly rendered treatment modalities in primary teeth wherein the pulp is irreversibly inflamed. To evaluate the sufficiency of calculated obturating material and quality of obturation in primary teeth using an obturagun device. Average root canal volume of 65 and 75 was calculated from cone beam computed tomography (CBCT) scans of children in the age-group of 5-9 years. Based on the average root canal volume and density of obturating material (Vitapex), quantity of obturating material required to obturate a single primary mandibular second molar was calculated. Computer-aided design (CAD)/computer-aided manufacturing (CAM) software was used to design obturagun, which was three-dimensional (3D) printed for study purposes. An in vitro pilot study (pulpectomy) was conducted on 20 extracted primary mandibular second molar to evaluate the efficacy of the obturagun. Average root canal volume of 75 was larger than 65. Approximately 68% of the root canals showed optimal obturation. Distal root canals were more void free as compared to mesial. In 70% of the cases, the calculated obturation material was sufficient to obturate a single primary mandibular second molar. Average root canal volume can be used to determine the quantity of obturating material. Obturagun can be used as an alternate obturating technique for primary teeth. Kalaskar R, Thosar NR, Kalaskar A. Evaluation of Novel Device "Obturagun" as a Root Canal Obturating Technique for Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(1):107-111.

Automatic Generation of Interference-Free and Posture-Smooth Toolpath for Robotic Belt Grinding of Complex Workpieces

Robotic belt grinding has shown great potential to achieve automatic machining of high-precision parts. However, its productivity in machining complex parts has been greatly limited by the problem that interference-free and posture-smooth toolpath planning is still a time-consuming and labor-intensive job. Therefore, this work presents a fully automatic and practical approach to facilitate interference-free and posture-smooth toolpath planning for robotic belt grinding of complex parts. With this approach, the interference correction spaces in two common belt grinding modes, namely, wheel face grinding and wheel edge grinding, are first established, where various types of interferences and their corresponding correction strategies are modeled. Then, two B-spline posture curves, which represent the rotational motion and translational motion of the workpiece for correcting interference throughout the entire cutter contact curve, are presented. With the two B-spline curves, a toolpath planning algorithm for robotic belt grinding of complex parts is further developed based on surface partitioning and iteratively correcting interference and smoothing grinding postures. The effectiveness and practicability of the proposed approach are validated by simulations and experimental studies, which demonstrates that the authors’ approach can significantly improve the toolpath planning efficiency and ground surface quality for complex parts as compared with the leading commercial computer-aided manufacturing (CAM) software.

Application of hybrid SFLA-ACO algorithm and CAM softwares for optimization of drilling tool path problems

In drilling process almost seventy percent time is spent in tool switching and moving the spindle from one hole to the other. This time travel is non productive as it does not take part in actual drilling process. Therefore, this non productive time needs to be optimized. Different metaheuristic algorithms have been applied to minimize this non productive tool travel time. In this study, two metaheuristic approaches, shuffled frog leaping algorithm (SFLA) and ant colony optimization (ACO) have been hybridized. In industry, the CAM softwares are employed for minimization of non productive tool travel time and it is considered that the path obtained by using the CAM softwares is the optimized path. However this is not the case in all problems. In order to show the contribution of the SFLA-ACO algorithm and to prove that results achieved through CAM softwares are not always optimized, hybrid SFLA-ACO algorithm has been applied to two drilling problems as case studies with the main objective of minimization of non productive tool travel time. The drilling problems which are taken from the manufacturing industry include ventilator manifold problem and lift axle mounting bracket problem. The results of hybrid SFLA-ACO algorithm have been compared with the results of commercially available computer aided manufacturing (CAM) software. For comparison purpose, the CAM softwares used are Creo 6.0, Pro E, Siemens NX and Solidworks. The comparison shows that the results of proposed hybrid SFLA-ACO algorithm are better than commercially available CAM softwares in both real world manufacturing problems.Article highlightsDifferent optimization techniques are being used for optimization of drilling tool path problems. In this paper two techniques SFLA and ACO has been combined to form a hybrid SFLA-ACO algorithm and has been applied to the real world industrial problems.Two real world problems have been taken from the local manufacturing industries. In both the problems the objective is to optimize the tool traveling time through hybrid SFLA-ACO and compare it with CAM software.Four CAM softwares have been used for comparison purpose. The problems undertaken are solved through these CAM software and compared with the results of hybrid SFLA-ACO results. As result of comparison it is found that in both the problems the performance of hybrid SFLA-ACO algorithm remains outclass. This signifies that results of CAM software in case of optimization of drilling tool path are not always optimal and these can be improved by using different optimization techniques.

Robot-guided Pre-machining for Repair by Cold Spray

Cold spraying is currently developing as a high potential technique for the repair of metallic components, particularly for the deposition of heat-and oxidation-sensitive materials. However, for the appropriate application, it is essential to prepare the component surface suitably to ensure optimum prerequisites for the subsequent material deposition by cold spray. Thus, this work proposes a concept for robot-guided pre-machining for repair by cold spray that includes removal of the damaged volume while considering the requirements for subsequent material deposition. In this concept, digital component and damage data define the dimensions and boundary conditions for material removal. This involves designing a parametric pre-machining target geometry for the damaged component by computer-aided design software that can handle variable surface types. The pre-machining target geometry is adapted to the damage characteristics by considering length, width, depth and orientation. To produce the pre-machining target geometry by machining tools, the adjusted component is exported to computer-aided manufacturing software. The applicability of this concept has been successfully demonstrated on digital use cases with exemplary components and damages as well as by practical application with a milling robot in a laboratory environment. The results demonstrate the capability of this concept for preparing damaged components and promise a high potential to ensure the required prerequisites for high-quality component repair by cold spray.

A Review on Utilization of Computer-Aided Design/Manufacturing Software in the Production of a Three-Wheeler Chassis

Currently, three-wheeler chassis are unheard of in the automobile business. It can be difficult to incorporate the characteristics of a conventional four-wheeled chassis into a three-wheeled chassis on a regular basis. It the present analytical study is to design and construct a three-wheeled chassis that can be used in real-time conditions. A computer-aided design (CAD) and computer-aided manufacturing (CAM) software package were proposed to be used to create the chassis in accordance with the specifications. This three-wheeled vehicle will serve as a substitute for two-wheeled vehicles in certain situations. According to the tadpole design, the vehicle will have two wheels up front and one wheel in the back. Because it is a perfect fit between the motorcycle and automobile categories, the vehicle must adhere to both motorcycle and automobile laws.

The Design of a Plastic Shredder Machine with The Crusher Cutting Knife Model for Environmentally Sustainable

Indonesia produced about 31.2 million metric tons of garbage in 2021. Roughly 87.1% of the total waste is comprised-evaluated of plastic waste. Plastic waste takes a very long time to break down in the environment. It took decades for trash made of plastic to decompose. Disorganized waste management at the landfill is a significant source of plastics-related problems. In order to reuse plastic garbage, it must be crushed up first before the recycling process. The primary objective of the design process for the crushing plastic machine used to shred plastic waste was to maximize productivity. The design of the machine that crushes plastic waste was created and prepared with the help of computer-aided design (CAD) and computer-aided manufacturing (CAM) software. One thousand and zero millimeters in length, three hundred and twenty millimeters in width, and twelve hundred and sixty millimeters in height describe this machine for chopping up plastic trash. In terms of crushing time and capacity, variations in the rotational speed of 1000, 1100, and 1200 blades in revolution per minute were optimal. The optimal crushing time for 2 kg-HDPE plastic waste was 37 seconds at 1200 revolutions per minute, followed by 1100 revolutions per minute; 2 kg-HDPE plastic waste was crushed and evaluated. HDPE plastic wastes have typically crushed faster in less time than PET plastic wastes. It has been evaluated and validated for any setting variation operation involving the crushing speed. Three kilograms of HDPE plastic waste yielded an optimum crushing capacity of 194.4 kg/hour at 1200 revolutions per minute. Next, at 1200 revolutions per minute, 2 kg-HDPE plastic waste is crushed. HDPE plastic wastes are typically more effective to crush than PET plastic wastes, regardless of the crushing speed setting variation operations. As a result of this study, plastic waste is being put to better use, helping to cut down on overall plastic use in the plastic waste management

Fit Accuracy of Complete Denture Base Fabricated by CAD/CAM Milling and 3D-Printing Methods.

Digital complete denture fabrication can be accomplished by either milling or three-dimensional (3D)-printing approach in which minimal distortion during processing contributes to effective denture base adaption, which leads to good denture retention. The purpose of this study was to compare the fit accuracy of milled and 3D-printed complete denture bases. The reference edentulous maxillary arch model was scanned to generate virtual denture bases using computer-aided manufacturing software that exports as standard tessellation language files. Denture bases were constructed using a milling and 3D-printing technique using digital light processing method (n = 10). Intaglio surfaces of denture bases were scanned and superimposed on the reference model. The fit accuracy was quantified as root mean square error and evaluated statistically using independent t-test comparisons with a significance level of 0.05. Milled denture bases were significantly more accurate in adaptation than 3D-printed dentures in the overall intaglio area and primary bearing area of denture bases. 3D-printed denture bases demonstrated significantly greater accuracy in adaptation than milled denture bases in the peripheral/posterior palatal seal area. Milled denture bases fit better in the overall and primary stress-bearing areas than 3D-printed dentures, while 3D-printed dentures appeared more accurate in the peripheral seal area, which had a minor undercut that is not suitable for using milling technology.

An In Vitro Study of Intaglio Surface, Periphery/Palatal Seal Area, and Primary Bearing Area Adaptation of 3D-Printed Denture Base Manufactured in Various Build Angles.

The objective of this research was to compare the adaptation in the overall intaglio surface, peripheral/posterior palatal seal area, and primary bearing area of the 3D-printed complete denture produced in 0, 45, and 90° build angles. A reference edentulous maxillary arch model was scanned to design virtual denture bases with computer-aided manufacturing (CAD) software with standard tessellation language (STL) files as output. Denture bases were fabricated by printing with a digital light processing (DLP) technique and divided into 3 groups according to build angles of 0°, 45°, and 90° (n = 10). To assess the adaptation, each STL file of the intaglio denture base was superimposed on the STL file of the reference model using surface-matching software. The adaptation was reported in root mean square error (RMSE) values and statically compared using one-way analyses of variance (ANOVA) and followed by the Turkey's test for multiple comparisons with a significance level of α = 0.05. Overall, intaglio surface adaptation of denture bases printed from three angles had no significant difference in adaption. In the peripheral/posterior palatal seal area, denture bases printed at a 90° build angle showed significantly better adaption than other groups. In the primary bearing area, denture bases printed at 45° and 90° had no significant difference in denture adaptation; however, they exhibited better denture base adaptation than the 0° group significantly. The build angle has no effect on adaptation in the overall intaglio surface area. The build angle of 90° provided the best adaptation in the peripheral/posterior palatal seal area. The 45° and 90° build angles provided better adaptation than 0° in the primary stress-bearing area.

Improvement in the efficiency of the five-axis machining of aerospace blisks.

Blisks are not easily machined because of their complex curved surfaces and the high-precision requirements of surface machining. Lightweight alloy materials with superior mechanical properties, such as titanium alloy and stainless steel, are popular material choices for manufacturing turbine blisks. However, these materials are difficult to cut and require advanced machine tools and processing technologies. Because aerospace-grade parts are complex and require precise dimensions and high surface quality, machining these parts by using three-axis machine tools is difficult. Using multi-axis machine tools for the machining of complex parts can cause the achievement of precise dimensions, high quality, and the required surface roughness. In the multi-axis machining of aerospace blisks, tool path planning is considered the most difficult task. In this study, we examined the implementation of five-axis machining technology for the manufacturing of an aerospace blisk. Processing modules from computer-aided manufacturing software (NX10) are used for five-axis tool path generating, and 5-axis machining numerical control code is generated through post-processing calculations. Solid cutting simulation software (VERICUT) is used to verify whether tools exhibited overcut or interference. A sensory tool holder (SPIKE) is used to analyze cutting force during the rough machining of a blisk. The sensory tool holder is also adopted to evaluate the spindle runout and tool holding status. In order to obtain a consistent cutting allowance and surface accuracy, the online measurement system is used to generate a measurement path for semi-finish and finish machining. The real cut is performed with SUS304 and demonstrates the practical application. Through improvements in process planning, the machining time was shortened by 16.5%.

Integrating Computational Fabrication Methods with Architectural Education

Today, technology is developing rapidly. It changes architectural design and building techniques. To these changes up education system should be updated and be integrated with the novel technology. Tomorrow’s professionals only be educated with this way. To make novel technology a part of architectural education, computational fabrication laboratories should be established and be integrated with architectural curriculum. They have the potential to transform architectural education processes. Within this context, this study tries to integrate computational fabrication methods with architectural education. The aim of the study is to share the process and results of a series of exercises applied to the use of computational fabrication tools and methods at the undergraduate level of architectural education. The study deals with exercise processes in a multidimensional scope. In this framework, constructivist learning processes, the concept of metacognition, the flipped classroom model and portfolio evaluation method played a role in the creation and evaluation of the exercise processes. Integrating computational fabrication laboratories with educational processes brings the student to play an active role in the exercise process. This approach is defined as constructivist learning process. In this way, it is ensured that the students can construct their own thinking and understanding processes. While the verb "teaching" is in question in conventional or objectivist education processes, the verb "learning" comes to the fore in constructivist processes. The instructor does not give the information directly but directs the student to reach the information. Flipped classroom model and portfolio evaluation are used as the methods of this study. The background of the exercises is supported by constructivist learning processes and metacognition concept. Within the exercise processes computational fabrication processes such as CNC laser machining and robotic milling were experienced. Within this study four exercises were performed to make the students experience computational fabrication methods: Unfolding, Tessellation, Sectioning, Folding and Moulding. To evaluate the exercise series success portfolio evaluation method was used. The answers in the portfolio to the questions of “What is the aim of this study?” and “What did you learn from this study?” are compared with the aim and learning outcomes of the exercises. As a result of this study, it is seen that the students’ knowledge on file-to-factory process is increased. They learned how to make ready a parametric model for computational fabrication. Based on student portfolios, it has been determined that students have begun to realize the potentials of computational fabrication tools. The students learned how to use computer aided manufacturing software, and even they could manage to define toolpaths on their own. This shows that, undergraduate architectural education level is not early to teach students computational fabrication tools and software.

Automated BIM-based CNC file generator for wood panel framing machines in construction manufacturing

Construction manufacturing companies are endeavoring to integrate new technologies and machinery automation throughout the various project phases in the ongoing shift away from traditional stick-built methods. The current practice in constructing manufacturing supports the integration of automated computer numerical control machines, which can undertake various operations and thereby reduce manual work. However, shop drawings need to be obtained from the building information model and imported to third-party software (such as computer-aided design / computer-aided manufacturing software) to generate the corresponding computer numerical control codes. This underscores the need for a fully automated solution for computer numerical control machines in construction manufacturing that reduces the reliance on third-party software, thereby reducing the time, effort, and cost otherwise spent on managing multiple software solutions. As such, the aim of this research is to develop a building information modelling-based automated tool to serve as a direct connection between the building information modelling environment and the automated machine. The tool facilitates the generation of a computer numerical control file directly from the building information model that will serve as an input to an automated wood-wall framing machine. For the wood framing machine under study, a set of rules was developed by which to generate the computer numerical control file directly from the building information model. This included developing an identification system for the main operations that can be performed by the machine and extracting information from the model that may be of relevance to the process. An add-on was then developed in Autodesk Revit to generate the computer numerical control file. The proposed methodology was validated by generating computer numerical control files using the developed add-on and inputting them to the machine. Using the generated computer numerical control files, the machine was found to be capable of properly performing the operations as planned.

Design and manufacturing of graded density components by material extrusion technologies

Innovative design methods and manufacturing technologies, such as lattice structures optimization and additive manufacturing, allow for the production of functional and extremely complex components. Recent literature shows limits in geometric modeling and data exchange, highlighting some improvements in the design of variable density lattice structures mainly for powder bed fusion technologies. Similar improvements are not available for material extrusion (MEX) technologies which show technological and numerical limits related to the computer numerical control programming language (G-code) generated by computer aided manufacturing (CAM) software. This work aims at overcoming the limits in fabricating graded density shell-based lattice structures for MEX technology by using the infill patterns available in the CAM software and editing the G-code based on a density map defined by volumetric models. Combining two usually separated phases, i.e., the geometric modeling and the CAM processing, several advantages are obtained, considering at the same time some of the technological constraints.The proposed approach is tested on a cubic sample and on a bracket fabricated by a fused filament fabrication technology. The results show that the method allows for the reduction of design efforts, amount of data exchanged, and processing time, obtaining an effective G-code and consistent components.

A Common First-Year Undergraduate Engineering Course in Manufacturing based on Industrial Robots and Flipped Classroom

The pedagogy of a first-year engineering course in manufacturing is presented. This course entitled Manufacturing and Society involves collaboration with social science, is based on industrial robots as the central theme to attract students’ interests and utilizes the flipped classroom approach for delivery. We hypothesize that, in one semester, recent high school graduates will be able to gain knowledge in manufacturing by learning the computer-aided engineering (CAD) software, applying CAD to design a penholder, fabricating the penholder using additive manufacturing and computer-aided manufacturing (CAM) software, programming the robot to create a toolpath for the pen, drawing using the pen on the penholder guided by a robot, and elaborating on impacts of robotic painting on society from a social science perspective. This course is designed to give students, regardless of their intended major in engineering, broad knowledge in manufacturing via 10 engineering, 3 social science, and 10 technical communication lectures; 8 labs; and 4 projects. The social science lectures and discussions focus on how knowledge about society can be used to inform design and manufacturing decisions, social science research methods for understanding how engineers and technology can impact people’s lives, and changing trends in work, the workplace, and the future workforce as it relates to manufacturing. This course aimed to give undergraduate first-year engineering students a positive view of advanced manufacturing and its impact on society. Student evaluations and comments were positive and affirmed the learning objective of teaching manufacturing to the first-year engineering students. The flipped classroom approach was demonstrated to be ideal during the COVID-19 pandemic with limited capacity for in-person lectures and labs. The use of flipped classrooms allowed students to learn at their own pace, review and reinforce knowledge, have a closer interaction with instructors, and reduce the number of technical errors using simulation tools. This course with the support of flipped classroom pedagogy can be successfully implemented in the post-pandemic era, devoting the time of the class to answer questions, expand upon the class content and have a closer in-person interaction with students.

Black Bone MRI for Virtual Surgical Planning in Craniomaxillofacial Surgery.

Advances in computer-aided design and computer-aided manufacturing software have improved translational applications of virtual surgical planning (VSP) in craniomaxillofacial surgery, allowing for precise and accurate fabrication of cutting guides, stereolithographic models, and custom implants. High-resolution computed tomography (CT) imaging has traditionally been the gold standard imaging modality for VSP in craniomaxillofacial surgery but delivers ionizing radiation. Black bone magnetic resonance imaging (MRI) reduces the risks related to radiation exposure and has comparable functionality when compared with CT for VSP. Our group has studied the accuracy of utilizing black bone MRI in planning and executing several types of craniofacial surgeries, including cranial vault remodeling, maxillary advancement, and mandibular reconstruction using fibular bone. Here, we review clinical applications of black bone MRI pertaining to VSP and three-dimensional (3D)-printed guide creation for craniomaxillofacial surgery. Herein, we review the existing literature and our institutional experience comparing black bone MRI and CT in VSP-generated 3D model creation in cadaveric craniofacial surgeries including cranial vault reconstruction, maxillary advancement, and mandibular reconstruction with fibular free flap. Cadaver studies have demonstrated the ability to perform VSP and execute the procedure based on black bone MRI data and achieve outcomes similar to CT when performed for cranial vault reshaping, maxillary advancement, and mandibular reconstruction with free fibula. Limitations of the technology include increased time and costs of the MRI compared with CT and the possible need for general anesthesia or sedation in the pediatric population. VSP and 3D surgical guide creation can be performed using black bone MRI with comparable accuracy to high-resolution CT scans in a wide variety of craniofacial reconstructions. Successful segmentation, VSP, and 3D printing of accurate guides from black bone MRI demonstrate potential to change the preoperative planning standard of care. Black bone MRI also reduces exposure to ionizing radiation, which is of particular concern for the pediatric population or patients undergoing multiple scans.