Newsletter Archives; Winter 2001
The SmithWorks Team standing behind their prototype jig.
Experience-Based Learning
A student can take a class in mechanics of materials or thermodynamics and master a certain body of information which is expected knowledge for a mechanical engineer. But how do you teach an engineer to solve a practical problem utilizing this and all the other knowledge he or she has acquired? How do you teach engineers to work together in teams? How do you teach project planning and good time management? Students in the department's capstone design projects learn and practice these and other skills which prepare them for the world in which they will work after graduation. Our students begin by taking ME 395, Introduction to Mechanical Design, where they study design process and methodology, decision making, optimization techniques, project planning and engineering economics, among other topics. This prepares them for ME 495, Mechanical Engineering Design, where they actually work on a project.Jeff Webb, Greg Sheahan and Aaron Verzwyvelt took ME 395 together in Winter Quarter 2000. During this time they prepared a comprehensive design proposal for SmithWorks. In ME 495 they were joined by Lisa Rosenow and Nick Hebb, who had taken ME 395 earlier. Their project involved a problem faced by SmithWorks, a local company which manufactures wooden cones and cylinders to support display tables and other items. The task facing the group: how to reduce the set-up time for cutting slats used to manufacture the cones, thus improving productivity.
The team first visited the SmithWorks shop in Ballard to see how the work was being done. They noted that the cones were not standardized, but that a different size was used for each application. The slats are custom-cut for each size of cone. Therefore a different jig must be used to cut the slats for each size cone. Since SmithWorks makes cones in over 100 different sizes, a great deal of time is consumed in setting up new jigs from scratch for each cutting. The team decided to channel their efforts into designing a single adjustable jig which could quickly be reset for each size cone.
The team spent hours in brainstorming sessions trying to come up with an appropriate design. They discovered that the more research they did, the more possibilities they developed. They finally worked out the details for an adjustable jig which could be rapidly reset to cut slats for different size cones. This jig was based on the relationship of angles, and reduced the number of cutting steps from nine to four. But it was still an unproven concept, an idea on paper. The team had to build a functional prototype to prove their concepts.
Building the prototype posed a number of challenges. The first two fully operable demonstration prototypes were constructed largely of wood. These prototypes proved the concept, but the team still had to decide on materials for the final unit. After much research a honeycombed aluminum, such as is used in aircraft construction, was selected for the cutting surface because of its strength and light weight. Every attempt was made during the design phase to identify off-the-shelf parts for the jig. This kept down cost and contributed to ease of construction. However vendors were often unresponsive because of the small quantity of materials required. Even with maximum use of off-the-shelf parts, about ten parts were unique and had to be hand-machined. The team had to compete for shop time with other classes and with classmates in ME 495 working on other projects. The team was uniform in praise of Russell Noe, manager of the Student Instructional Workshops, for his ideas and invaluable assistance in teaching machining techniques. Hal Smith, the client who sponsored the project, was very supportive, visiting the campus frequently to work with the team and giving input on the desired features of the jig. He took the team to his shop to show them his existing operation and to discuss with them plant layout and how the new jig could fit in.
The finished product was delivered on time, and proved a major improvement over the previous method used to cut the slats. With just a few quick adjustments the jig could be reconfigured to cut slats for a cone of a different size. A large amount of time was saved in jig set-up, thereby increasing worker productivity. For the team, the big payoff was the experience they gained. They had studied the design process, project planning and time management in ME 395. But in ME 495 they applied what they learned and made decisions under the pressure of an inflexible deadline. Jeff Webb said that he really learned time management (or mismanagement) from the project. Lisa Rosenow said she gained valuable experience in using high-tech materials, and could easily have spent much more time learning about them had that time been available. She said she now knows firsthand why first prototypes seldom go into production. The team built two prototypes before the final "production model" was built, and each model was a big improvement over the previous one.
All members of the team cited teamwork as the key to the success of the project. Each had the opportunity to lead a sub-team and to be the person responsible for some aspect of the project. Each had to work with others individually and with the group as a whole, both as a leader and a team member. They had to make decisions under pressure imposed by time and resource constraints. These things can be studied, but it was the actual experience of doing that really brought the lessons home to each member of the team. It will be this experience, as well as knowledge gained from classes, which each student takes with him or her into the workplace.
If you would like to know more about ME 395/495 and capstone projects visit our website at www.me.washington.edu/~dig/medesign.
