AC 2008-1170: REVERSE ENGINEERING TO DESIGN FORWARD: ANINTRODUCTION TO ENGINEERING EXPERIENTIAL LEARNING MODULEWITH VIDEO PODCASTS

Steven Shooter, Bucknell UniversitySteven Shooter, Ph.D., P.E. is a Professor of Mechanical Engineering at Bucknell Universitywhere he has taught for thirteen years. He teaches Senior Design, Mechanical Design, Mechanics,Mechatronics, and Introduction to Engineering. His research is in the area of designmethodology, information management in design and robotics. He is a registered professionalengineer in Pennsylvania and consults considerably with industry. He is currently a PI on an NSFCyber Infrastructure Teams project to examine techniques for exploiting the cyber infrastructurein support of engineering education through product dissection and reverse engineering.

© American Society for Engineering Education, 2008

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Reverse Engineering to Design Forward:

An Introduction to Engineering Experiential Learning Module

with Video Podcasts Abstract

Reverse engineering is the practice of taking products apart (product dissection) to discover how it works and gain insight into why it was done that way. This is a common practice in industry and an important part of the product development cycle. Often the first customer of a company’s new product is a competitor who will completely tear apart, scrutinize, analyze and test in order to benchmark against their own offering. A Bucknell University Alumnus (class of 98) has done just that for his company that has catapulted their product to $40 million in annual sales in just two years. This paper will describe a three week module that is incorporated into an interdisciplinary Introduction to Engineering course. The module uses product dissection and reverse engineering as the guiding principle to establish improved design requirements and make suggestions for better designs. Nine fifty-minute lectures and three two-hour laboratories are used to show how a simple, every-day product like a stapler has many opportunities for improvement. The students dissect several staplers on the market and then use design methods to suggest a new stapler to satisfy a potential market. The module follows the case of Accentra, Inc. who has seen considerable market success through the launch of their PaperPro line of ergonomic staplers. The laboratory exercises are supplemented with instructional video podcasts that asynchronously guide the students through the product dissections. Introduction

Product dissection has been used in a variety of ways to successfully engage engineering students in their learning. Intellectual and physical activities such as dissection help to anchor knowledge and practice of engineering in the minds of students6,7 (Sheppard, 1992 a,b) and has been successfully used to help students identify relationships between engineering fundamentals and hardware design8,9 (Agogino, 1992, Brereton, 1998). Product dissection provides “hands-on” activities to couple engineering principles with significant visual feedback10,11,12 (Barr 2000, Lamancusa, 1996, Otto, 2001), and such “learning by doing” activities encourage the development of curiosity, proficiency and manual dexterity, three desirable traits of an engineer13 (Beaudin, 1995). Dissection also gives students early exposure to functional products and processes, and introducing such experiences early in the students’ academic careers has been shown to increase motivation and retention14 (Carlson 1997). While many benefits to product dissection have been identified, there exist several challenges: (1) start-up and maintenance costs, (2) space for disassembly and storage, (3) preparation of educational materials and activities, and (4) access to more complex products such as copiers, refrigerators or automobiles. In response a partnership of nine universities with 32 faculty has assembled to establish a National Engineering Dissection Cyber-Collaboratory that builds on the CIBER-U project15 (Simpson, 2007) and is supported by the National Science Foundation’s CI-TEAM program. The intent is to establish a cyber-collaboratory that utilizes a shared set of cyberinfrastructure-based respositories, design tools and teaching materials rooted in engineering

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dissection. The goals of this CI-Team implementation project include: 1. Deploying a cyber-collaboratory to support physical and virtual dissection of engineered

products and systems; 2. Creating and disseminating educational materials nationally, including development and

implementation of collaborative design exercises across the participating universities; 3. Assessing the educational impact and CI competency of the 12,000 participating

engineering and CS/IST students including user adoption of the cyber-collaboratory; and 4. Engaging under-represented groups and K-12 to promote a diverse CI-savvy workforce.

One interesting aspect of the cyberinfrastructure is the proliferation of new devices and media for interaction. We can now access the internet with devices such as personal data assistants, telephones, digital book readers, and i-Pods, among others. The richness and diversity of the media has expanded far beyond traditional text or even hypertext to include integrated multimedia with images, sound, video, CAD, simulations etc. Today’s students are accustomed to using these devices. They also have a high degree of expectation for sophistication of the educational materials in their classes. So, the opportunity arises to build on the strength of the cyberinfrastructure and the utilization of these new technologies. In particular, there is an opportunity to use video podcasts to support asynchronous learning in the classroom and laboratory. Many universities have some form of an Introduction to Engineering course for first year students. The goals are often to teach students about the fields of engineering and introduce them to engineering problem solving. The course16,17,18 at Bucknell University includes three-week breakout seminars that focus on design in the context of each of the engineering departments. Students choose from among eight or nine options of seminars to fill their requirement for three. Seminars typically average 30 students each. There are a total of nine 50-minute class meetings and three 2-hour labs. Reverse Engineering to Design Forward - aka Stapler Wars

The Stapler Wars seminar follows a real-world case study of the development of the PaperPro innovative line of staplers developed and sold by Accentra, Inc. The director of new product development and co-founder of Accentra is a Bucknell University Mechanical Engineering alumnus class of 1998. Accentra has seen remarkable success since its founding in 2003 with sales of over $40 million in 2006. There story has been highlighted in Time magazine19 (Cole, 2005) and widely touted as one of the most innovative new products. But what is of particular interest to this class is how the company used reverse engineering and a focus on the customer to compete in a market that had been stagnant of innovation for decades. Swingline had held 80% of the market share. The key to PaperPro’s success is the use of mechanical advantage and spring loading to reduce the required hand force and increase reliability; both concepts are core topics to mechanical engineering. Figure 1 shows the original PaperPro desktop stapler. While the seminar follows the PaperPro story line for three weeks, it has specific educational objectives as shown in Table 1. These objectives are broken into categories of Overall, Process and Technical. Overall objectives are sufficiently general to apply to all the fields of engineering. Process objectives focus on best practices expected of all engineers. Technical

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Figure 1: The PaperPro Desktop Stapler

Table 1: Seminar Objectives

Objective Category

Students will demonstrate an understanding the field of mechanical engineering with respect to other fields of engineering

Overall

Students will identify the role of design methods Overall

Students will demonstrate an understanding the role of the customer in design of products

Overall

Students will work in multi-disciplinary teams Overall

Use appropriate laboratory techniques Process

Apply an engineering decision-making process Process

Apply design methods as appropriate Process

Establish project timelines and milestones Process

Use creative design techniques Process

Establish measurable design specifications Technical

Formulate a product architecture Technical

Formulate a functional block diagram Technical

Identify types of levers Technical

Calculate mechanical advantage Technical

Calculate spring constant and force in a spring Technical

Sketch mechanical elements Technical

Prepare a final design report Technical

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objectives focus more on the domain of mechanical engineering, but are certainly applicable to other fields of engineering as well. The first Overall objective is not intended to be assessable, but rather to help students in their decision on an engineering major. The Process and Technical objectives are assessable. Assessment is conducted through regular homework problems, lab reports, a final quiz, and a design project report. All seminars are required to have at least 50% of the student grade from an assessment tool that is completed only by the individual. The other part of the grade comes from group materials. Seminar Timeline

Day 1 - Introduction The first day of the seminar sets the stage for the next three weeks. It begins with the story of Accentra and PaperPro. The idea is to make it clear that there are many opportunities to improve on even the most mundane products to achieve marketable success. It helps that there is the Bucknell University tie to the product with the alumnus to build personal interest. To reinforce the impact of the stapler design I show them the Time magazine article19 (Cole, 2005) and assign reading it for homework. I then introduce them to product dissection and reverse engineering by dissecting some common kitchen appliances such as an electric mixer. I also show them a virtual dissection of the mixer created with CAD software. The intent is to get them to see the inter-relation of form and function from perspectives of reverse engineering and design as shown in Figure 2. They are also assigned homework reading of two articles on reverse engineering from Mechanical Engineering Magazine20,21(Abrams, 2006; Brown, 2006) that they can access from the website of the American Society of Mechanical Engineers (a shameless plug for drafting student membership).

Figure 2: Relationship of Form and Function in Reverse Engineering and Design

Day 2 – Engineering Anthropology

The second day of class introduces the product realization process and the importance of a focus on the customer. I show the Nightline video of IDEO and the creation of their shopping cart. We discuss the design process and the importance of learning about the competition by talking to customers and observing the use of products. For homework students must then use observation and questioning of two market segments for staplers. For each market segment the groups of two must answer the following questions:

FORM FUNCTION

DESIGN

FUNCTION FORM

REVERSE ENGINEERING

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Who? Who are the typical users of staplers? What societal role or occupations? ie. students.

What? What are they stapling? Types of materials? Sizes? Thicknesses? To What? What staples?

When? When do they staple stuff? How often?

Where? Where do they staple stuff? Where do they store the stapler?

Why? Why do they staple stuff? Why use a staple rather than some other way to do it?

How? How do they staple stuff? How do they hold the stapler? How do they load it? What else might they being doing with it?

How Much? How much stuff do they staple? How many pages are typical? How many pages are too much?

Often they identified potential customers as students, teachers and academic assistants. However, many groups identified other markets such as shopkeepers, carpenters, clothing makers and even surgeons. They also used additional resources such as webpages and articles they found on the internet to answer the questions. I was overwhelmed with their initiative.

Lab 1 – Dissect Common Staplers

The first two-hour lab has students dissect common staplers in groups of three or four. Half of the groups receive one stapler and half receive another. They are given safety goggles, a screwdriver, a ruler and a bathroom scale. They start by reviewing the stapler for ergonomics and aesthetics and then testing its performance. They then test the force required to staple different numbers of sheets of paper with the aid of the scale. They perform several tests for each number of sheets and average the results for the test. After testing they dissect the stapler. For each component they must name it, sketch it with primary dimensions and identify its principle function. They must also show the interconnectivity of the components. Before re-assembling their stapler, they meet with another group to compare and contrast the two staplers. Their lab report that is due in two class periods contains these materials along with answers to follow-up questions. Figure 3 shows the staplers the students dissect and Figure 4 shows an action shot of the lab.

Day 3: Engineering Requirements

The focus of this class is to emphasize the need for establishing measurable engineering requirements. The material covered includes an overview of Quality Function Deployment. I use the example of a nail clipper to highlight the aspects of translating the voice of the customer into measurable engineering requirements. The nail clipper is a good example because it is a common household item that also uses a lever. For homework students must translate the results from their anthropology study of staplers to measurable engineering requirements. They must do this exercise individually and independently. They later compare and compile their results with their group to establish a unified set of requirements.

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Figure 3: Two Standard Staplers and one Dissected

Figure 4: Students Performing Lab 1

Day 4: Product Architecture

A product architecture describes the interconnectivity of components in an assembly. It not only illustrates which components contact eachother, but also describes the type of contact as rigid or having mobility with kinematic connection. While the initial concept is straight forward, students can have difficulty identifying the kinematic joints. So, the lecture focuses on lots of examples starting with the nail clipper. For homework students individually create an architecture diagram of their stapler from Lab 1 as shown in Figure 5.

Day 5: Functional Description

Day 5 introduces a formal description of function using block diagrams that illustrate the flow of material, energy and information. This is a fairly high-level concept that is not easily grasped by the students. Lots of examples help, but they found it difficult to recreate a functional decomposition. For homework they individually do a functional decomposition of a stapler. Figure 6 shows the first level function description.

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Figure 5: Stapler Product Architecture

Figure 6: Functional Description of Stapler

Lab 2: Dissect and Reverse Engineer the Easyshot Staple Gun

The Easyshot staple gun is a cheaper version of the Powershot both sold by Black and Decker. It uses mechanical advantage from a double lever mechanism to charge a spring to activate the striker that drives the staple. This technology and patent was the foundation for the PaperPro concept. In fact, the founder of Accentra worked for Black and Decker before starting this company. Through the lab students see how levers amplify force and a spring stores and

coupled by pin å

couple

couple

coupled äby pin

secure

guide

Attach papers with staple

staple is in original form Paper is stapled

hand

Hand force Hand force

staple

hand

paper

staple

paper

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discharges energy. They again test the hand force needed for stapling using the bathroom scales. They compare the input force to the output force. They also compare and contrast the results from the dissection and reverse engineering of this stapler to those from the previous lab. Figure 7 shows the Easyshot stapler and Figure 8 shows action shots from the lab. The lab report is due two class periods later.

Day 6: Mechanical Advantage

Day 6 introduces mechanical advantage and basic physics of a lever. Free body diagrams are introduced with the placement of forces. There are lots of examples. Students then do an individual homework assignment calculating mechanical advantage of different levers. One problem is a double lever like that used on the Easyshot.

Day 7: Mechanics of Springs

Day 7 introduces different types of springs and the basic spring equations. There is a lot of show-and-tell passing around springs of various shapes and sizes. It is also a day of catch-up with questions from lab 2 and mechanical advantage.

Lab 3: Dissect and Reverse Engineer the PaperPro Stapler

In Lab 3 students repeat a very similar process as before but on the PaperPro stapler. They do not completely dissect the stapler themselves because the case is sonically welded. I also created cut-away views of the stapler by removing portions of the casing with a saw. The students compare and contrast the PaperPro to the traditional stapler and the Easyshot. I did not have them complete a full lab because the design project is about to be assigned.

Figure 7: Easyshot Stapler

Power spring

Recoil spring Handle

Lever 1 Lever 2

Strike

Pin

Absorber

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Figure 8: Action shots from Lab 2

Figure 9: Cut-Away View of the PaperPro

Day 8: Designing a New Stapler

Day 8 involves a rehash of the PaperPro saga. I explain to them how they have stepped through the reverse engineering process much like that done by Accentra. I also show them the patent that Accentra obtained on the design. Finally, they are assigned the final design project where they must create a conceptual design of a new stapler. They then realize that they have been stepped through that entire process. The design reports are due at the end of the following week, when they will have moved on to another seminar.

Day 9: Quiz and Wrap-Up

Students take an individual quiz on the topics covered throughout the seminar. I summarize the seminar and answer any questions they have on the final design project. The following week I

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start all over again at Day 1 with a new class.

Results

The final design project produced many creative ideas for new staplers. Each of them built upon the mechanical advantage technology of the PaperPro. Some concepts included a large stapler for 100 sheets, a micro stapler for backpacks, child-friendly staplers with character themes and safety protection, a clothing stapler, and a surgical stapler.

Assessment indicated that the students met the objectives of the course with a high level of proficiency in many areas. Table 2 shows direct assessment guidelines used for all courses in the mechanical engineering department. Table 3 shows the assessment method and average rating for the 84 students who participated in the seminar. Many of the objectives were achieved with an average level of Accomplished. Sketching, mechanical advantage and levers showed higher levels of achievement between accomplished and exemplary. One topic of particular weakness, however, was in functional modeling. Each seminar group had trouble grasping this concept to be able to independently create a function block model of a stapler. The concept of functions transforming material, energy and information appeared to be too abstract for their level of academic maturity.

Table 2: Direct Assessment Rubric

0

Beginning

1

Developing

2

Accomplished

3

Exemplary

4

Stated

Objective or

Performance

Failure to meet the beginning level of performance.

Description of identifiable performance characteristics reflecting a beginning level of performance.

Description of identifiable performance characteristics reflecting development and movement toward mastery of performance.

Description of identifiable performance characteristics reflecting mastery of performance.

Description of identifiable performance characteristics reflecting the highest level of performance.

Generic

Problem

Solving

Outcome

Unable to link

the fundamental principles to the

problem.

(Below 60%)

Basic terminology

recognized and fundamental

principles linked to problem. (60-70%)

Reasonable problem solving methods applied with significant

errors. (71-84%)

Correct problem solving methods

applied with minor errors.

(85-93%)

Problem completed accurately

with correct interpretation of results if required.

(94-100%)

Generic

Project

Outcome

Feature absent (Below 60%)

Feature provided but lacking many

desired attributes. (60-70%)

Feature completed with most required attributes but with significant room for improvement.

(71-84%)

Feature completed to the

full extent expected. (85-93%)

Feature goes beyond

requirements, suitable to

serve as target for future students.

(94-100%)

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Table 3 Seminar Objective Assessments

Objective Assessment

Method

Average

Score

Students will gain a better understanding of mechanical engineering

Not assessed

Students will gain a better understanding of design methods

Quiz; project 2.8

Students will gain a better understanding of the role of the customer in design of products

HWs 1, 2, quiz project

3.1

Students will gain a better understanding of the role of product dissection and reverse engineering in design of products

Labs 3.2

Students will work in multi-disciplinary teams

Labs, project 3.0

Use appropriate laboratory techniques Labs 3.1

Apply an engineering decision-making process

Labs, project 2.8

Apply design methods as appropriate project 3.0

Establish project timelines and milestones project 3.0

Use creative design techniques Lab 1; project 2.9

Establish measurable design specifications Lab 1, hw, quiz 3.1

Formulate a product architecture Lab 2, hw, quiz 3.2

Formulate a functional block diagram Lab 2, hw, quiz 2.1

Identify types of levers Hw, quiz 3.4

Calculate mechanical advantage HW, quiz 3.3

Calculate spring constant and force in a spring

Hw, quiz 3.1

Sketch mechanical elements Lab 1, project 3.3

Prepare a final design report project 3.0

The seminars were rated high by the students. In response to the question, “This seminar was a good introduction to the basics of engineering and design”, the response was a mean of 4.7 where 5 indicated “Strongly Agree” and 4 “Agree”. In response to “I would recommend this seminar to other students interested in the subject” the mean was 4.75. The value of the laboratory experience was rated high at 4.44.

Comments from the students were also extremely positive. A sample includes:

‚ This seminar was put together very effectively to give an overview of reverse engineering and design. Many topics were briefly covered which allowed for an overall look at design and mechanical engineering.

‚ The hands-on taking apart of the stapler really helped to experience reverse engineering & mechanical advantage s very helpful.

‚ It was a great seminar. The hands-on activities and interesting professional stories kept me interested in engineering all together.

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‚ The seminar took a nice linear approach to the subject and the Prof had good previous knowledge of the subject matter.

‚ This seminar was an intriguing and enlightening look into the world of design. It pushed the stereotypes aside and proved to be very interesting. It was nice to feel like I was actually working towards something, rather than punching numbers into some random questions.

‚ We got to see exactly how different staplers worked by doing actual reverse engineering. Then we learned about and actually went through a whole design process. This hands-on, do-it-yourself approach helped to enforce the concepts, and make the information real.

‚ The labs were the strongest part of the seminar, because they helped greatly to understand the basic concepts of reverse engineering and design.

Video PodCasts

Students reported that one of their favorite aspects of the seminar was the product dissection labs. To support the labs, students were given detailed step-by-step instructions on what to do and reflection questions to answer after particular tasks. Lab sizes of 12 to 15 students were supported by both the instructor and a lab teaching assistant. Student questions and requests for assistance kept both the instructor and the TA very busy. In response we examined ways to use modern technologies to support the asynchronous laboratory activities. The result was the creation of a series of video podcasts that support the laboratory activity. Students can view the step-by-step instructions and conduct the exercises at their own pace. Each activity is demonstrated so they can see what they are supposed to do.

In addition to the instructional podcast for each lab, we created follow-up podcasts. These provide the answers to the questions posed in the lab and discuss higher-level aspects of what they should have gained by the exercises.

This seminar has not yet been run a second time. However, the podcasts have been made available to other schools. The video podcasts have been used by a middle school class to support their dissection exercises. That middle school project is described in22 (West, 2008). The instructor of that class reported that the podcasts helped the students tremendously with completing their exercises. Conclusions

Product dissection and reverse engineering can be a powerful technique for teaching engineering and design. Students gain profound insight through self discovery. A strong contributor to the success of the seminar is the real-world story line that connects the activities. Students follow along as they discover the interconnectivity of reverse engineering and design. They also get to see how much opportunity for improvement there is with a seemingly mundane product such as a stapler. If they never look at a stapler the same way again, then I have truly made some impact. Course materials have been shared with colleagues at other institutions. Several schools have now included stapler dissection exercises.

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Educational Materials

All educational materials used in the seminar including Powerpoint slides, handouts, homework assignments, laboratory materials and video podcasts can be found at http://www.students.bucknell.edu/projects/dissection/.

Acknowledgements

We gratefully acknowledge the National Science Foundation through Grant No. OCI-0636139. Any opinions, findings and conclusions or recommendations presented in this paper are those of the authors and do not necessarily reflect the views of the National Science Foundation.

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