MAKER: 3-D–Printing Evolution in Engineering Education: The Things We Make

This paper presents the five stages of evolution in the inexpensive 3D printing movement by defining and measuring the degree of acceptance/usefulness of inexpensive 3D printing technologies in an engineering educational environment. The stages (Familiarization, Design, Extension, Material Exploration, and Expansion) are defined as a function of quality and quantity of students’ involvement through the degrees of complexity, ingenuity, and utility of printed objects, as well as the students’ sophistication in using additional machines and techniques supporting 3D printing processes. A number of examples from an engineering department’s 3D printing laboratory are provided to illustrate the various stages of 3D printing evolution. Introduction Experiments and other hands-on activities are well-known cornerstones of education and are highly supported by the experiential education philosophy established by Dewey, and the experiential learning cycle developed by Kolb. Designs, physical models, and prototypes are accepted as an integral part of engineering education in both education research and engineering curricula . Furthermore, engineering texts address 3D printing technology and practice. The 3D-printing revolution is here. New inexpensive 3D printers are introduced weekly. Universities, two-year colleges, and K-12 institutions are buying 3D printers for their design courses. Many of the middle schools and high schools in the country already have at least one 3D printer. Technology enthusiasts belonging to the Makerspace movement often use communal space equipped with multiple 3D printers, laser cutters/engravers, and CNC machines. While the 3D printers based on fused deposition modeling (FDM) are still prevalent, other inexpensive 3Dprinting technologies are slowly gaining acceptance among builders. Also, preand postprocessing tools and techniques are being developed at an increased pace. The engineering department’s 3D-printing lab at our institution is used primarily by undergraduate engineering students (mechatronics and industrial engineering) for mechanical designs in various courses and in support of technical extracurricular activities. It includes ten inexpensive 3D printers with preand post-processing tools and employs two half-time student technicians. Some facets of the 3D-printing lab are described elsewhere.The described lab experiences are based on over five thousand print-time hours and over two thousand printed objects ranging from Thingiverse bracelets to sophisticated multi-part assemblies of students’ own designs. In this work, an evolution in printing practices is described and viewed through a prism of objects printed. This work categorizes 3D printed objects as students move through different evolutionary stages while they become more experienced and engaged with 3D printing technologies. The stages are addressed in the following section. Five stages of 3D printing evolution In this work, the development of 3D printing knowledge and expertise is categorized in five evolutionary stages as shown in Table 1. Table 1. The five stages of 3D printing expertise evolution Stage Name Characteristic Stage 1 Familiarization Manufacturer supplied and web-based objects printed Stage 2 Design Student-designed (CAD) objects printed Stage 3 Extension Preand post-processing tools used Stage 4 Material Exploration Materials beyond ABS and PLA explored Stage 5 Expansion New 3D printing technologies/equipment researched Stage 1: Familiarization At the Familiarization stage, after the 3D printers are assembled and the slicing software installed, students print test objects supplied by the 3D printer manufacturer. Then, they download project files from the Web (e.g. Thingiverse) and print some of the objects. As the students become more proficient they print more complex objects and assemblies. This stage also includes the development of skills dealing with 3D printer platform calibration, filament changing, object removal from printers, object clean up, and nozzle maintenance. Also, students gain experience with printing platform preparation including the use of Kapton tape, acetone/ABS (acrylonitrile butadiene styrene) mix, or hairspray when using ABS filament, as well as paper tape, glass, or paper glue when using PLA (polylactic acid) filament. Figure 1 depicts typical objects printed at this stage as well as some of the tools used. Figure 1-a shows a set of bracelets printed in PLA. Even though PLA is not flexible, due to their geometry the bracelets are. Figure 1-b presents an assembly. Multiple parts are printed separately and then assembled into a final product. Each elephant in Figure 1-c is an assembly where all the parts of the elephant are printed simultaneously. After an elephant is released, the legs (in pairs) and the head can move independently allowing the elephant to be placed in different positions. Figure 1d presents some tools used in object removal and cleaning of the support material. Spatulas, pliers, woodcarving tools, scissors, files, etc. can be used for this purpose. In some cases, the material used for the support structure is dissolvable. Here, students immerse objects into an acid solution to clean the parts. However, the dissolvable support material technique is somewhat cumbersome, slow, and expensive.