Development of a flash drive design project for engineering graphics ...

Development of a Flash Drive Design Project for Engineering Graphics and Design Paul D. Schreuders Engineering Student Services and Academic Programs Texas A&M University College Station, TX, USA [email protected] Abstract— A major challenge in engineering design graphics classes has been the development of semester-long projects, which supports curricular goals while maintaining student interest. In this paper, we will describe a project to develop flash drive casings. The project scenario was structured as a request by a client to design a themed set of flash drive casings and a presentation case suitable for use as a gift to outstanding employees and high value clients. Each student rapid prototyped one flash drive casing of his or her own design. The project was implemented as a series of team and individual assignments spread over the semester, with the product of those assignments returned to the instructors in memo format. This project was implemented in three phases, over several semesters, with the number of students increasing at each stage to ensure that its full scale adoption was successful. The initial test of the curricular elements was made in two, approximately 20 student summer classes. At that time, several challenges were identified. Reflection on this phase revealed a need for additional written documentation containing “project hints” to help students provide designs that meet the rapid prototyper’s production constraints. It was also determined that a number of intermediate assignments were needed to motivate students to remain on schedule for project completion. The project is currently nearing the end of development phase 2 and most design issues have been resolved. However, curriculum changes are warranted in response to student conceptual difficulties. As in many graphics design projects, a major challenge has been the development of three-dimensional spatial skills. Students have had difficulty creating designs containing layered structures, particularly those needed to secure the electronics within the casing. As expected in a first semester, first year course, some students have shown an inability to follow detailed instructions. While this weakness is normally only a grading issue, the flash drive covers are prototyped directly from their CAD files, making type of error particularly problematic. One major success of the project has been student excitement in the project and the improvement of their graphics skills from re-creation of existing designs to the development of novel designs.

Keywords—Graphics Project Development; Flash Drive

I. INTRODUCTION The Engineering Design Graphics Program’s Industrial Advisory Board recently recommended modification of current curriculum to emphasize original design and the introduction of “real world” issues, such as budgeting and nongraphics-based communications. In addition, the program purchased a state-of-the-art rapid prototyper with improved output quality and increased production rate. These recommendations were implemented through a

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Jeffrey M. Otey Engineering Student Services and Academic Programs Texas A&M University College Station, TX, USA [email protected] major revision of the course project. The authors chose to apply the “independent project method” described by Lee [1]. As noted by Bell et al. [2], a well-designed scenario has the potential to: (1) “provide opportunities for students to integrate the learning outcomes from the lecture and laboratory-based teaching sessions,” (2) “enhance generic skills such as teamwork, problem solving and communication,” and (3) “extend their knowledge using some of the principles of PBL.” Further, their results “demonstrate the value of a hybrid approach to an engineering curriculum, which embeds elements of problem- and project-based learning alongside traditional lecture and laboratory teaching.” [2]. The availability of rapid prototypers allows an engineer (or engineering student) to move through the entire design process from idea to part creation [3]. Additionally, the prototypers assess no penalty for the creation of a wide variety of complex objects with a high degree of manufacturing precision [4], and are emerging as an industrial process [5-7]. This capacity makes it an effective adjunct to computer aided design by allowing students to realize their designs. Until recently, the cost of rapid prototypers has been prohibitively expensive, but they have decreased in cost over the last few years, with low-end model prices ranging from $400 to $4,400 [8]. II. PROJECT DEVELOPMENT A. Student Population Description. Students in this course were drawn from a variety of disciplines, ranging from engineering transfer students to industrial distribution majors. General studies students also enroll in this course, as they attempt to enter engineering after failing to meet the College of Engineering’s entrance requirements. The majority of students were in their first year of college and therefore had minimal ability to perform the analysis required by an intensive design project. B. Project Development Phases The ultimate goal of this revision was to introduce a project suitable for introduction into the graphics component of the Freshman Engineering Program and into the first year engineering design graphics course. The combined course sections serve several thousand students per year, in sections approaching 100 students. On this scale, even minor issues in

the modified curriculum had the potential to cause significant disruption in the course. Therefore, the authors chose to introduce curriculum modifications in three phasees, with revisions occurring at the end of each phase. The phasees and their scheduled semesters were:

Exercise – The project was assigneed in the form of a memo to the project teams. The brainsto orming exercise required pairs of students to generate 50 ideeas for flash drive casings in 10 minutes. The rapid pace of idea generation was deliberately chosen to reduce the level of intragroup criticism.

Phase 1: The creation and testing of thhe design project and the development of a project manuual – summer sessions I and II of 2012 Phase 2: Intermediate scale-up of curricullum to increasing numbers of student and revision of the project manual – Fall Semester 2012 and Spring Semesteer 2013 Phase 3: Full scale introduction of the prooject into courses – Fall Semester 2013

Week 2: Project Teams Assign ned – The project was assigned to teams of 4 members. Teaam membership was chosen by the instructor. Additional descriptive information regarding project was provided to the studentt teams and they were asked to begin researching possible design ns for their drive casings.

C. Additional Curricular Goals As previously noted, the project was useed as a vehicle to introduce non-CAD curricular content to thhe students. The authors chose to insert the following goals innto the course: (1) the introduction of an engineering design pparadigm, with an emphasis on satisfying design constraints, (22) increasing the variety of communication methods appliedd by the students, (3) the basic elements of project planning, paarticularly the use of Gantt and PERT (Project Evaluation annd Review Technique) charts, and (4) the development of basiic budgets.

Week 4: Concept Memo and Associated A Sketches Due – The memo required each group meember to submit sketches of potential flash drive casing designss and themes for consideration. The memos were returned witth critique of the sketches and comments on potential probleems with specific designs.

D. Course Project Description The project required students to design a series of custom The students were flash drive casings and a presentation case. T required to identify a common theme for thee presentation set. The theme (e.g. biomimetics of ocean creeatures, important engineering structures, or military weapons eengineering) tying the drives together needed to be suitable for uuse a gift from an engineering consulting firm. The exact areaas of expertise of the firm were left undefined to allow the sttudents maximum flexibility in their choice of theme. Exam mples of student designs are shown at right in Figures 1 and 2.

Week 3: Full Project Manual Handed H Out – The project structure was provided to the studeents and a detailed description of the project’s deliverables was supplied.

Week 6: Flash Drive Electroniccs CAD Drawing Due, Detailed Discussion of the Project Po ortfolio, and a Project Planning Lecture and Assignment – The T students were assigned the creation of a dimensioned CAD drawing, based on measurements of the flash drive electro onics performed by the students using a digital micrometer. The lecture described project planning processes. Students were required to generate PERT and Gantt charts for the project using u the software package GanttProject [9] and to assign respo onsibilities for the project.

E. Course Assignments As the project was developed, an effort waas made to create a project structure that could be reused in future semesters (1) a sequence of design memos, (2) a final deesign portfolio, (3) a project presentation, and (4) rapid protottyping each student's design.with minimal adaptation. Thus, aan effort was made to isolate the item designed, so that othher items could easily be inserted/exchanged. The authors choose to implement these goals through the following major project assignments:

ve casings. Figure. 1. Examples of designs for flash driv

The first two assignments for the project w were designed to move the students through an iterative desiggn process, with the last two assignments capping the project. Throughout the semester, a number of smaller homework asssignments were given to keep the students on track for the major project completion. E. Course Assignment Schedule The following timeline was followed durinng the semester:

Figure. 2. Example flash drive cases printed d on an Objet rapid prototyper (left and middle). Example set of flash driv ves and a case based on the space program (right). The case was design ned to mimic a segment of the international space station.

Week 1: Project Assignment and Designn Brainstorming

Week 8: Final Design Choice Memo Due – This memo contained the final flash drive desiign and a theme that bound the flash drives into a cohesive set. The students were required gs of the flash drives. to attach updated isometric drawing Week 11: Parametric Model of o Flash Drive Electronics

Due – These models were used in flash drive assembly drawings and provided a mechanism to allow students to examine issues such as part fits and physical assembly problems. Week 12: Files for Each Individual’s Flash Drive Casing Design for Rapid Prototyping Due – CAD files used by the rapid prototyper were reviewed prior to printing. Subject to available printer time, the rejected designs could be revised and resubmitted for printing. Week 13: Working Drawings of Individual’s Proto- typed Flash Drive Casing Due – This assignment was aimed at keeping students progressing towards project completion. Week 15: Project Portfolios Due and Presentations Given – The project presentations were structured to resemble intra-company sales pitches with the projects “competing” for the right to be produced. F. Phase Assessments 1) Phase 1: We introduced the curriculum into two small classes with less than 20 students in each section. The smaller classes allowed intensive instructor/student interaction as challenges in the curriculum schedule and project developed. The issues that arose during this phase were (1) a need for additional documentation to clarify the assignments, (2) The need for tolerance values for the Objet rapid prototyper, and (3) the need for design recommendations for use with the rapid prototyper. 2) Phase 2: In phase 2, we scaled the project up to 5 class sections of 50 to 55 students each and entailed printing of over 1,400 separate parts. At the end of the semester, meetings were held students and with the design laboratory manager. The discussions with the students yielded only minor recommendations including rescheduling some of the assignments and earlier creation of the STL files used by the rapid prototyper. Discussions with the design laboratory manager indicated that the parts were printed over a 4 week period at the end of the semester, with the rapid prototyper operating continually during that period. This level of output requires consideration of several factors, including: Material Cost: The most obvious factor was the cost of the material (~$300/kg). A decision was made to limit each student to 30,000 mm (~31g) of printed material, based on available funds from course fees. Design Laboratory Time: Time required for printing using a rapid prototyper falls into two categories; student technician time and printing time. Technician time typically occurred during the setup of the print jobs and post-printing part cleaning. Depending on the equipment used, these times can vary greatly. In addition, the printing load end of each semester, occasionally resulted in mechanical problems with the prototypers. Printing Time: Rapid prototypes require only minimal oversight during the printing process, permitting overnight and weekend print jobs, and making it most efficient to print large numbers of parts in each manufacturing run. Most rapid prototypers have constrained print volumes. However, because

the flash drive casings are small; the constraining factor is their cross-sectional area, since this limits the number of parts that can be printed in any batch. Therefore, the authors have added a maximum cross-sectional area restriction to the project’s design constraints. Submission Management: Each student was allowed to print one flash drive casing. A file and parts management scheme was required in order to ensure that printed parts were credited and returned to the individual. The expansion to the larger number of students quickly revealed that the system needed to be revised to provide additional information on the submitted parts and in the submission file names. As a consequence, students were required to emboss their team number and name to more easily facilitate return of student casings. A post semester review halfway through phase 2 indicated that students were experiencing problems with the design process, rather than the project itself. Therefore, materials were added to support the students’ design skills. The materials included: addition of a design paradigm to the course materials [11, 12] and addition of material to help students build teaming skills and to understand the issues that occur during team formation based on Tuckman’s stages of group development [10]. III. CONCLUSIONS The authors’ experience in this curriculum revision has confirmed the benefits of a multi-stage review process. This development, currently in the second “scale-up” phase of the planned curriculum improvement, has benefitted from the re- vision cycle. We are nearing the end of the second semester of phase two and now have reasonable confidence in the project’s ability to survive contact with the larger number of students. In addition, the program’s faculty has adopted the project for other engineering classes and the authors are working to adapt the project to those needs. IV. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

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