Realizing proof of concept in machine design with 3D printing

Abstract

The Virtual Machine Design course was developed to teach basic concepts of mechanical component design to mechatronics engineering students. The laboratory section of the course is geared towards designing electromechanical devices. Students develop prototypes of their designs in order to strengthen their design and visualization skills. The prototypes also give students the opportunity for hands-on learning. 3D printers, which can convert a CAD model to a physical product, are popular among the designers and inventors. As the printers become more affordable, 3D printing is moving from being a demo technology to being a hands on production device. These days, engineering students can successfully build physical models of their designs with low-cost 3D printers. In this paper, the applicability of 3D rapid prototyping in a virtual machine design course is investigated, and impact of this technology on student learning is also reported. The design projects were assigned to the selectively random group of students. Mechanical devices of different energy generation technologies involving both stationary and dynamic parts were designed and prototyped for a comparative study. Each team selected one of the following energy generation technologies: hydro, wind, solar, or tidal. Students identified the components of their design and built a CAD Model of those components. Based on the loading type and the nature of the structure, they were asked to analyze force and stress; and to determine the size of their structure. Students were required to design no more than ten dissimilar components and to consider industry standards, safety, and the operating environment in addition to the functional requirements of the design. Although both 3D printing and traditional manufacturing options were available, most of the students have chosen 3D printing using ABS plastics to create their components. Once the components were built and assembled the electrical systems was installed to a complete working models for electricity generation. Students built the prototypes based on their own calculation and analysis. The students were graded using a rubric that included expected design content and steps to be followed. The design task was divided into analytical work, simulation, and prototyping. Evidence of learning included a technical report, a working physical model, and a presentation. The effectiveness of this work was assessed by using a Likert scale survey at the end of the study period. Integration of 3D printing helped to improve the rigor of the course by adding prototyping capability into existing analytical and simulation based instruction. As a part of the prototyping process, students were able to acquire skills in 3D printing, which will be useful to them in future coursework, including their senior capstone project, and in professional endeavors. This integration enabled the instructor to teach mechanical design in a single course starting from basics of stress analysis to prototyping.