An introduction to engineering through an integrated reverse engineering and design graphics project

Journal of Engineering Education, Oct 2000 by Barr, Ronald E, Schmidt, Philip S, Krueger, Thomas J, Twu, Chu-Yun

ABSTRACT

This paper discusses a new freshman course that merges previous topics in the "Introduction to Mechanical Engineering" and "Engineering Design Graphics" courses into a single integrated teaching effort. The main objective of the new course is to introduce students to mechanical engineering education and practice through lectures and laboratory experiences. A major effort in the course is devoted to a reverse engineering team project. The students are divided into four-member teams and are instructed to select a simple mechanical assembly for dissection. They study and disassemble their object into basic constituent components, documenting this process with freehand sketches and notes. They use these sketches and other measured dimensions to construct 3-D solid computer models of each major component. The teams then obtain .STL files of the solid models, which are used to make rapid physical prototypes of their parts. The teams conclude their project activities by generating engineering drawings directly from the 3-D geometric data base. All of these efforts are integrated, documented, and submitted to the instructor as a final team project report.

I. INTRODUCTION

A new freshman course at the University of Texas at Austin merges previous topics in "Introduction to Mechanical Engineering" and "Engineering Design Graphics" courses. The main objective of this new course is to introduce students to mechanical engineering education and practice through lectures and laboratory experiences. Lecture topics include orientation to university facilities and services, teamwork skills, introduction to the mechanical design process, and guest speakers from industry. A major effort in the course is devoted to a reverse engineering team project that involves mechanical dissection.', The course also includes concomitant laboratory exercises in engineering design and graphics.'

The course is taught using both a large lecture class and smaller laboratory sections. The large lecture class format allows direct access to approximately 120 students simultaneously for one hour per week. In this large lecture class, students are oriented to mechanical engineering education and practice through a series of lectures and assignments. Guest lectures include representatives from the engineering library, career placement center, and coop office. In addition, speakers come from industries such as Ford Motor Company and Proctor and Gamble. Regular class lectures are supported by PowerPoint slide presentations on various engineering topics, as shown in table 1. The lecture homework exercises are listed in table 2 and include both individual assignments and team exercises that support group activities. In an effort to better communicate with the large number of students in this lecture class, a special Internet web-site has been developed for the course and is located at the following URL: http://www.me.utexas.edu/-me302/.

The smaller laboratory sections of 24 students meet in computer graphics labs for approximately four hours per week. In these smaller sections, they matriculate through a series of typical engineering design graphics exercises. These include freehand sketching of pictorial and orthographic views, sectioning, dimensioning practices, and 3-D computer modeling. They also are exposed to graphics applications such as mass properties and rapid prototyping. The current software used for computer modeling is AutoCAD-14, and the hardware system used for rapid prototyping is JP System-5.

11. INTEGRATED REvERSE ENGINEERING PROJECT

A major effort in the course is devoted to a reverse engineering team project. The students are divided into four-member teams based on the results of a Myers-Briggs Type Indicator (MBTI) survey and a team questionnaire (homework assignment #3). This is done in an effort to foster healthy team dynamics for the project. Team members are also chosen based on their common enrollment in the graphics laboratory sections. The teams are instructed to select a simple mechanical assembly, such as a door knob, pencil sharpener, or toy gun, which will be used for the mechanical dissection process.

The team members submit their selected object in the form of a reverse engineering project proposal (homework assignment #4). This proposal includes a cover page, a general written description of the object, and a graphic picture. Selection of this object tends to be crucial for the success of the team, and instructor approval is warranted before the object is accepted. Typical objects selected are listed in table 3. The team project involving a door knob (figure 1) has been selected for illustration in this paper.

-4. Project Planning

After the object has been approved by the instructor, the teams meet and plan their dissection project activities through exercises involving charts and graphs (homework assignment #5). They organize their entire semester schedule, week-by-week, using a Gantt chart (figure 2). An initial engineering study of the object is conducted and they establish its major input-output function using a black-box diagram (figure 3). This allows the team to study the functionality of the device before the dissection process is initiated.