key: cord-0057778-kd0z2twe authors: Hao, Rui-can; Liu, Hua-gang title: Research on 3D Printing and Its Application in CAD Teaching date: 2020-10-30 journal: e-Learning, e-Education, and Online Training DOI: 10.1007/978-3-030-63955-6_27 sha: f19ad700dab93316bf377b5e8f68ecbcfe220990 doc_id: 57778 cord_uid: kd0z2twe 3D printing is a rapid prototyping technology in recent years. Computer aided design (CAD) combining with 3D printing in university is helpful for students to understand the design work. The history and characteristics of 3D printing technology were introduced. The technology and material used in 3D printer was summarized. The application of 3D printing technology in teaching was studied. Combining 3D printing technology and CAD design cases is helpful for students to understand the designed model directly and to master the three-view drawing of objects intuitively. Integrating 3D printing technology into mechanical design competition is an effective means to promote teaching effect. Apply 3D printing into CAD teaching could improve students’ subjective initiative in learning, expand students’ innovative thinking, and improve teaching quality. 3D printing (3DP) is a kind of rapid prototyping technology, also known as additive manufacturing [1] . It is a technology based on the digital model file, which uses adhesive materials such as powder metal or plastic to construct objects by layer printing. The advantages of 3D printing are to save raw materials and realize customized manufacturing, which is an optimal technology to realize green manufacturing. 3D printing is usually realized by digital material printer. It is often used in mold manufacturing, industrial design and other fields to make models, and then gradually used in the direct manufacturing of some products [2, 3] . There are already parts printed with this technology. The technology has applications in bionics [4, 5] , biomedical and medical science [6] [7] [8] [9] , engineering and construction (AEC) [10] [11] [12] , jewelry, footwear, industrial design [13] , architecture" automotive, aerospace, education, geographic information systems, civil engineering, firearms and other fields [14] . Computer aided design (CAD) course is the pre work for manufacturing and printing. The necessary module show is helpful for the design work. So combining 3D printing with CAD courses is a novel teaching method to help teaching and learning work go on smoothly. 3D printing technology is a rapid prototyping technology, which could make adhesive materials into a three-dimensional physical object layer by layer by 3D printer. It is mainly base on the digital model files, and the special adhesive materials are mainly powder metal, wax material, plastic, and so on. The main principle of this technology is to put the data information and raw materials into the printer through the computer technology. The printer prints the products layer by layer according to the program set by the computer system, and finally presents a three-dimensional physical object. 3D printing technology has the characteristics of simple operation and convenience. Through 3D printing technology, objects can be displayed more intuitively, vividly and stereoscopically, which is also more convenient for 3D printing technology than traditional manufacturing technology. With the continuous development of science and technology, the level of 3D printing technology has also been greatly improved. Nowadays, 3D printing technology is more and more widely used. For example, it plays an important role in mechanical manufacturing, industrial design, architecture, biomedicine and other fields. Compared with traditional printing methods, 3D printing technology has the characteristics of high operation coefficient, cost saving, high production flexibility and automation. Since 3D printing technology has so many advantages and characteristics, it is deeply concerned and valued by experts and industries in society. Table 1 shows the development of 3D printing at home and abroad [15] . Ordinary printers used in daily life can print plane objects designed by computers. The so-called 3D printer and ordinary printer work on the same principle, but the printing materials are different. The printing materials of ordinary printers are ink and paper, while 3D printers are equipped with different "printing materials" such as metal, ceramics, plastic, sand, etc., which are real raw materials. After the printer is connected to the computer, the "printing materials" can be stacked layer by layer through the computer control, and finally the blueprint on the computer can be turned into a real object. Figure 1 is a 3D printer which has successfully printed a F1 car. There are many different technologies for 3D printing. They differ in the way that the materials are available and the parts are created with different layers of construction. Commonly used materials for 3D printing include nylon glass fiber, durable nylon material, gypsum material, aluminum material, titanium alloy, stainless steel, silver plating, gold plating and rubber materials. Table 2 shows cumulative technology and basic materials for different types of technology. The advantage of 3D printing technology is the directly manufacturing which could take out the data from computer and manufacture the parts directly at once. In some aspects, direct printing can not only improve the efficiency, but also reduce the cost. Replacing the traditional teaching method, the methods combining in teaching and the effects are introduce in the following. Combining CAD design cases with 3D printing technology could help students to understand the designed model directly and to master the three-view drawing intuitively. A designed example is shown in Fig. 2 . This is a part in screw propeller for students to practice designing. If there is a real object printed corresponding the design drawing, it is helpful for students to evaluate the designed parts themselves and improve their designing work furtherly. Another designed example is shown in Fig. 3 . This is a mobile phone supporter for students to practice using three-dimension software. Through 3D printing, we could observe the shape and surface of objects in all directions and improve the quality by measuring the actual dimensions and precisions of objects to improve the designing. It could also help to solve some problems in CNC manufacturing. Integrating 3D printing into mechanical design competition is an effective means to promote teaching effect. In order to enhance the innovation consciousness of students and cultivate their practical ability, the school strives to create conditions to support students to participate in all kinds of design competitions. In the competition of mechanical design, it is often necessary to process some parts. The cost of parts processed by traditional turning, milling, drilling and other methods is relatively high, and the processing time is relatively long. Using 3D printing technology to design these parts is not only cheap and time-saving, but also can improve the competitiveness of the work, reduce the harm of mechanical tools for people, and stimulate the enthusiasm of students to participate in the competition. At the same time, the integration of 3D printing technology into the competition of mechanical design specialty can promote the teaching reform of mechanical related specialty, strengthen the cooperation between school and enterprise, form the connection between specialty and industry, take the opportunity of design competition, combine the competition project and curriculum reform project, refine the connotation of skill competition, lead and deepen the teaching reform and development of mechanical design specialty. Taking 3D printing technology as a new auxiliary means of classroom teaching, teachers have mastered the construction method of simple model and the basic use method of 3D printer. Combined with the inquiry teaching method, students can experience the fun of "learning by doing" more excitedly, which is conducive to stimulating students' enthusiasm and innovative thinking. Improve Students' Subjective Initiative in Learning. The introduction of 3D printing technology into the classroom can enrich teaching methods, and present abstract concepts, virtual models and designs in the form of materialization in front of students. It can bring strong sense of visual impact and reality, stimulate students' interest in learning and enthusiasm for practice, and improve their enthusiasm for learning, and make them more active in learning. Expand Students' Innovative Thinking. 3D printing not only solves the disadvantages of traditional teaching, but also enriches students' vision and exercises their threedimensional thinking. This is not only helpful to improve the teaching efficiency of teachers and students' learning efficiency, but also an important link to expand the development of students' innovation ability, which is of positive significance to the cultivation of innovative talents. Improve Teaching Quality. According to the needs of teaching, we can set up teaching model resource base. The practical problems in teaching can be solved by designing teaching content or modifying model printing. With the help of new technology, the quality of teaching, and the ability of students' technical innovation could be improved. 3D printing is a novel manufacturing technology which could transfer the data in computer to the real objects layer by layer by 3D printer. The development of 3D printing technology is studied. And the material for printing is summarized. Applying the 3D printing technology in teaching is meaningful. Combining 3D printing into design cases and mechanical design competitions are studied for teaching. The application could improve the students' initiative in learning, expand students' innovative thinking and improve teaching quality. The teaching application of 3D printing technology deserves further study and discussions. Rapid prototyping; studies from state university of new york reveal new findings on rapid prototyping (Investigation of compressive deformation behaviors of cubic periodic cellular structural cubes through 3D printed parts and FE simulations) Influence of 3D printing on mechanical manufacturing and automation Effect of microwave-salt synergetic pre-treatment on the 3D printing performance of SPI-strawberry ink system Tension mechanical behavior of 3D printed composite materials inspired by nacre Development of new biocompatible 3D printed graphene oxide-based scaffolds One step multimaterial 3D printing for the fabrication of a photometric detector flow cell 3D printed biodegradable implants as an individualized drug delivery system for local chemotherapy of osteosarcoma 3D printing technology in percutaneous nephrolithotomy: babyhood but will be promising Development of a CT imaging phantom of anthromorphic lung using fused deposition modeling 3D printing Engineering gelatin-based alginate/carbon nanotubes blend bioink for direct 3D printing of vessel constructs A 3D printing strategy for fabricating in situ topographical scaffolds using pluronic F-127 Bonding between silicones and thermoplastics using 3D printed mechanical interlocking Mechanics of bioinspired functionally graded soft-hard composites made by multi-material 3D printing Open hole tensile testing of 3D printed parts using in-house fabricated PLA filament The influence of the development of 3D printing on the training of applied talents Acknowledgements. Thanks to the fund and support from the general program of Beijing Municipal Education Commission (KM201910858005) and General program of the 13th five year plan of Beijing Education Science in 2020 (CCDB2020135).