enhancing design students comfort and versatility in the...
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Paper ID #9085
Enhancing Design Students’ Comfort and Versatility in the Shop: A Project-Based Approach
Dr. Ari W Epstein, Massachusetts Institute of Technology
ARI W. EPSTEIN is a Lecturer in the Terrascope program and the Department of Civil and Environ-mental Engineering (CEE) at the Massachusetts Institute of Technology (MIT), where he specializes inteam-oriented, project-based, student-driven learning. He is particularly interested in developing ways tointegrate free-choice learning (the kind of learning promoted by museums, community-based organiza-tions, media and other outlets) into the academic curriculum, integrating formal and informal educationalstrategies.
Mr. Stephen Rudolph, MIT
STEPHEN RUDOLPH is a technical instructor in the Department of Civil and Environmental Engineeringat the Massachusetts Institute of Technology. He works with students in project-based classes, assistingthem with the design, construction, and implementation of projects. He is especially interested in waysto help students quickly gain confidence in the labs and learn the safe and productive use of hand tools,machine tools, and lab equipment.
Prof. Herbert H. Einstein, Massachusetts Institute of Technology
Professor of Civil and Environmental Engineering Room 1-342 MIT Cambridge MA 02139
Prof. Pedro M. Reis, Departments of Civil & Environmental Engineering and Department of Mechanical En-gineering, Massachusetts Institute of Technology
Pedro Reis is the Esther and Harold E. Edgerton Assistant Professor of Mechanical Engineering andCivil and Environmental Engineering at the Massachusetts Institute of Technology. His research group(EGS.Lab: Elasticity, Geometry and Statistics Laboratory) is dedicated to the fundamental understandingof the mechanics of thin objects and their intrinsic geometric nonlinearities. Professor Reis received aB.Sc. in Physics from the University of Manchester, UK (1999), a Certificate of Advanced Studies inMathematics (Part III Maths) from St. John’s College and DAMTP, University of Cambridge (2000) anda Ph.D. in physics from the University of Manchester, UK (2004). He then moved as a Post-Doc to theBenjamin Levich Institute for Physico-Chemical Hydrodynamics at the City College of New York (2004-2005). Between 2005 and 2007 he was a CNRS Post-Doc at the ESPCI in Paris. He joined MIT in thesummer of 2007 as an Applied Mathematics Instructor in the Department of Mathematics before startinghis current Assistant Professor appointment in July 2010.
c©American Society for Engineering Education, 2014
Enhancing Design Students’ Comfort and Versatility in the Shop: A Project-Based Approach
Abstract “Introduction to Civil and Environmental Engineering Design I” is a sophomore-level class, required of Civil and Environmental Engineering (CEE) majors at the Massachusetts Institute of Technology (MIT). The main objective of this class is to teach students how to work effectively in design teams on open-ended problems and how to design, prototype and fabricate functional devices (experimental apparatus, demonstration/teaching tools, observational equipment, etc.) relevant to CEE topics. When the current version of the class was introduced in the fall of 2007, the instructors found that many students were unfamiliar with, and to some extent afraid of, shop equipment and power tools. In addition, many of them were unaware of a large number of relevant tools, techniques and materials, limiting the possible variety and sophistication of their final design/fabrication projects and likely requiring that a large amount of individualized instruction be given during the design/fabrication process, stretching class resources thin and slowing the students’ work. In response to these concerns, instructors developed an introductory fabrication exercise, to be completed by all students in the class—a project specifically designed to increase the students’ comfort and ability in the shop and their familiarity with materials and techniques, in order to broaden the scope of their final design projects. Over the years the introductory project has been adapted and altered; on the basis of survey data, direct observation and reports from instructors of other classes, the authors believe this now to be an extremely effective and useful exercise. In its current format, teams of students build Archimedes-screw devices out of wood, PVC, acrylic and other materials, and they test these devices using modern sensors and image-processing equipment. Participation in the introductory project has demonstrably increased the students’ comfort in the shop and, perhaps more importantly, has progressively made students much more familiar with the tools, materials and techniques available to them. In response, their final class projects have shown increased sophistication and utility. Moreover, instructors of the next class in the CEE design sequence report that students leave this class better prepared than they did in the past—so much so that those instructors have been able to eliminate introductory exercises of their own. We here share details of the project and its evolution, in the hope that other instructors of similar classes, facing similar challenges, will find it useful. Introduction “Introduction to Civil and Environmental Engineering I” is a sophomore-level class required of Civil and Environmental Engineering (CEE) majors at the Massachusetts Institute of Technology (MIT). It forms part of a two-class sequence: the first class (which we discuss in this paper) introduces students to the collaborative design process; using design to address open-ended problems; fundamentals of team-building; principles of design; and the design, prototyping and fabrication of apparatus relevant to civil and environmental engineering. For the first half of the semester, students work in teams on a theoretical design problem. (In recent years the assignment has been to propose specific improvements to Harvard University’s plans to build an expanded campus in the nearby Allston neighborhood.) During the second half of the semester, the teams
work on a hands-on design/prototyping/fabrication project inspired by some aspect of the work they have done in the first half of the semester; students have considerable freedom in deciding the topic, approach and scope of this project. Usually these projects involve the design and fabrication of experimental instruments and protocols or of devices that demonstrate some of the physical principles underlying improvements students have proposed in Harvard’s plans. The second class of the sequence, taken the following semester, builds on this experience and engages students in design projects having to do with sensors, instrumentation, control and related topics. In order for this sequence of classes to be most effective, students must emerge from the first class with appropriate shop skills and the ability to envision designs that incorporate a variety of fabrication techniques and materials. When the current version of the class was first taught, the instructors were concerned that many students were unfamiliar with shop procedures and tools; in some cases students were nervous or afraid of using power tools. Moreover, students generally were not fully aware of the wide variety of materials and fabrication techniques available to them. They might therefore not be able to envision or produce design projects at the level of sophistication intended by the instructors, and might require intensive instruction in the shop while working on projects. (And, of course, some students’ reluctance to work with power tools could pose a severe limitation to their future progress.) In order to address these issues, instructors developed an introductory shop exercise, to be carried out by all students in the class, in order to introduce specific tools, techniques and materials, and to help students learn procedures and expectations specific to the CEE student shop. Based on feedback and survey responses from students, on our own observation of students’ work in the shop, and on the nature of the projects students proposed and completed during the semester, we found the exercise to be an immediate success. Over the years we have modified it in a number of ways (to be described below), both in order to address concerns and in order to incorporate new tools and techniques, as they became available. The exercise continues to play an important role in this class, and instructors from the next class in the sequence report that they believe it brings students into their class better prepared, even to the extent that those instructors have been able to eliminate some introductory exercises of their own, giving them the opportunity to cover other material in more depth. The purpose of this paper is threefold: to describe the evolution of the exercise over time, including some discussion of lessons learned; to highlight general principles that might guide other instructors wishing to create similar projects in their own contexts; and to provide specific guidance and materials for any instructors who may wish to implement the particular exercise we have developed. We begin by describing the “rolling planter” project—the exercise developed during the first semester of teaching the class. Next we describe that project’s replacement, the “Archimedes screw” exercise, developed two years later in response to certain concerns about the planter project, and we describe ways in which the Archimedes-screw project has been updated and improved over time. Finally we detail some lessons learned as we have developed, implemented and refined the exercise. In appendices we provide shop drawings, parts lists, procedures and timetables for the exercise, for the benefit of instructors who would like to implement this exercise or to adapt it for their own institutions.
Version 1.0: the “rolling planter” project The first version of this project was developed in response to a need the instructors became aware of early in the first semester in which we taught the class. Fortunately there was time, while students were working on the theoretical design project that occupies the first half of the semester, to create, test and implement the first version of this shop exercise. As a first stage in development, instructors developed a list of tools, techniques and materials with which we wanted students to be familiar. For example, we anticipated that students might want to create class projects involving hydraulic models, and so would benefit from knowing how to make watertight acrylic boxes—something almost none of the students had seen as being within their competence, although it is not a difficult skill to learn. After some brainstorming, we decided to have students build an unusual and, we hoped, amusing object: a planter with wheels, partially resembling the primitive car seen in the old “Flintstones” cartoon series. (See Figure 1 for examples.) The exercise was designed with the intention that it would be interesting and useful, both to students with very little shop experience and to those who already felt competent using tools and machines. Table 1 details the learning objectives of the exercise and lists areas of the planter project that helped students meet those objectives.
Figure 1: Prototype of the original "rolling planter" and two finished, decorated planters. Table 1: Learning objectives as incorporated in the rolling-planter exercise.
Tool/Technique/Material Implementation in Planter Joining acrylic to make watertight containers Planter box and drainage tray Hole saw Wheels Band saw Frame Drill press Chassis and frame Cordless drill Chassis and drainage tray Hand tools (e.g. screwdriver, wrenches) Wheels, attachment of frame to chassis Belt Sander Frame and spacers (dowels) Assembling moving parts with proper freedom of motion
Joint between wheels and chassis
General woodworking and joining Project as a whole The rolling planter was to be built in four hours, spread over two class periods, with each student building his or her own planter. Then students were to take the planters home, plant seeds if they
wished (we supplied soil and seeds) and decorate the planters. A later class period was devoted to racing planters down a slope and judging decorated planters for creativity, fit and finish. The planter project was a success. Students reported enjoying the experience, and those who had been most concerned about using power tools became much more comfortable. Overall, based on results from surveys distributed in class (see Table 2), students gained appreciably in their confidence with tools, techniques and materials. Perhaps most significantly, nearly every final project designed by the students incorporated elements to which the students were introduced by the planter project. For example, in the first year of the planter project five out of six final student projects included significant use of watertight acrylic boxes. Of course, point-of-use instruction was still necessary for many tools, but this instruction could be targeted towards particular students’ needs, rather than covering general use of each tool itself. One unexpected use of the planter project was as an example of how a design team might approach an open-ended problem. We created a class presentation on the development of the planter project, complete with images of our brainstorming notes, photographs of early prototypes and other elements, as a way of demonstrating to the students that we ourselves used the design and collaboration techniques we were trying to teach them. Assessment The planter exercise was carried out in the fall semesters of the 2007-8 and 2008-9 academic years. In the first year of the project 31 students took the class. In the second year 53 students enrolled; that year the class was taught in two separate sections, to minimize overcrowding in the shop. In both years the great majority of students taking the class were sophomores majoring in Civil and Environmental Engineering.
Assessment of the project was based on:
1. Surveys distributed to students shortly after the project’s completion 2. Instructors’ observations of students’ comfort and skill with shop equipment and
materials 3. Instructors’ observations of the degree to which students incorporated materials and
processes from the exercise into their final class projects. As mentioned above, measured by the latter two criteria the exercise was extremely successful. That conclusion is supported by the survey results shown below. For example, before the rolling-planter exercise 60.5% of students rated themselves as having low to moderate skill levels (between 1 and 3 on a 5-point scale) on the band saw; after the exercise, only 12.3% of students rated their skill level on the band saw as low to moderate.
Table 2a: Survey-based assessment of Rolling Planter exercise. Answers based on 5-point Likert scale.
Rate your skill level in the following areas before and after the project:
Average Before Project
% Answers Below 4 Before Project
AverageAfter
Project
% Answers Below 4
After Project
Response Rate (%)
Band Saw 2.6 60.5 3.9 12.3 96.4% Drill Press 2.9 51.9 4.3 4.9 96.4% Cordless Drill 3.3 40.7 4.3 0.0 96.4% Working with Acrylic
1.5 88.9 4.1 17.3 96.4%
Table 2b: Survey-based assessment of Rolling Planter exercise; answers based on 5-point Likert scale.
Question Average Answer Response RateThe project was interesting/fun. 4.6 96.4% I am now better prepared to work in the lab and shop. 4.3 96.2% I have learned things about materials and machining operations that will be helpful when designing something that I will be building.
4.4 96.2%
On open-ended responses, students overwhelmingly indicated that they had found the project enjoyable and effective; many of them also indicated, however, that they would have enjoyed a more complex project, and one that was more directly relevant to the work they would be doing within their major. Version 2.0, the Archimedes screw Despite the success and effectiveness of the rolling-planter exercise, after the second year in which students built planters the class’s teaching staff came to feel that it might be better to address the problem anew, and to develop a different introductory project. The primary reason for this change was that we wanted to create a project that would model for students the level of sophistication we expected to see in their own work; the planter, although fun and instructive to build, is not a physically complex device. A new exercise could also broaden the scope of materials and techniques to which the project exposed students, and could create greater learning opportunities for students who already had shop experience, by giving them the chance to work with additional tools or materials to which they might not yet have had exposure. Finally, and importantly, the rolling planter was at most tangentially related to civil and environmental engineering; we wanted to find a project that the students would see as being relevant to the work they were planning to do as upperclassmen, ideally a project that would enable them to expand their understanding of topics within the field. Ultimately, we decided that all of these purposes could be met by changing the project to one in which students built a modern-day implementation of the Archimedes screw.
The Archimedes screw is one of the oldest tools used in hydraulic engineering to transfer fluids, suspensions and slurries between two locations with a vertical elevation difference. Its invention is typically credited to Archimedes (circa 287–212 B.C.E.)1 and it has been used extensively since ancient times. Interestingly, however, Archimedes himself never made reference to this invention in any of his works2. More recently, Archimedes screws have also been used in reverse for power generation, due to their high efficiency in situations of low head (less than 20m), variable flow rate and high sediment load, and their ability to accommodate migration of fish3-5. Our implementation (shown in Figure 2) is a table-top device, in which the screw action is carried out by a flexible hose wrapped around a drum made of PVC piping, angled so that one end of this assembly is submerged in a reservoir tank. The angle at which the assembly descends into the tank is adjustable, and by using different lengths of hose it is also possible to adjust the pitch (turns per unit drum length) of the hose. There is a handle, with which the user can turn the assembly to work the pump, and a splash pan, higher than the reservoir, to gather the pumped water. Prior to the exercise, students are asked in an informal written survey to rate their confidence and skill in using a variety of tools and machines. Based on their answers the students are divided into teams of two, pairing those who are relatively experienced in the shop with those who are not; the more experienced students are asked to let their partners take the lead when possible, so that they don’t inadvertently take over the project. The exercise takes three two-hour class periods to build—time that instructors feel is well-spent, given the benefits the project brings and the degree to which it enables students to work more quickly later on.
Figure 2a: CAD views of the Archimedes-screw project
Figure 2b: Schematic views of the Archimedes-screw project
Figure 2c: Completed Archimedes-screw projects. Students experiment with ways to wrap the hose around the drum, and examine how those wrappings affect the device’s function.
The Archimedes-screw exercise, being much more complex than the rolling planter, called for a correspondingly more complex development process, involving multiple prototypes and alternative designs. In addition, a new instructional challenge was added: because this project involves so many more steps and tools than does the planter, managing the flow of students around the workspace and from task to task would not be simple. We carried out multiple tests to assess the amount of time a given step would require, the number of students who could or should be grouped at a given station, and so forth. A key element of this testing was to find people who could accurately simulate students’ behavior—they needed to be inexpert in the shop, and unfamiliar with the details of the project. (Tests carried out in which instructors took the place of students sometimes yielded overly optimistic results.) In short, it was necessary for us to prototype the process, not just the product. Table 3: Learning objectives as incorporated in the Archimedes-screw exercise.
Tool/Technique/Material Implementation in Archimedes screw Joining acrylic to make watertight containers Reservoir and splash pan Use of silicone sealant Reservoir and splash pan Band saw Splash-pan support and clamp board (board that
supports top of drum assembly) Drill press Blocks that support upper end of drum Cordless drill Overall assembly Hand tools (e.g. screwdriver, wrenches) Overall assembly Horizontal band saw (cut-off saw) Pivot-shaft pins for upper block assembly Belt Sander Pivot-shaft pins for upper block assembly Working with metal Pivot-shaft pins for upper block assembly Working with structural plywood Base and clamp board Cutting and cementing PVC Drum, axle, handle Jigsaw Slots in clamp board Spade bit Blocks Flexible hose; watertight joints between hose and acrylic structures
Hose on drum, siphon that empties reservoir after use
Hinges, angle brackets, other fittings Final assembly Laser cutter Acrylic components Threading/tapping Fittings holding hose to drum Shop drawings Project as a whole Team-based construction Project as a whole Plug-and-play sensors Instrumentation Lab Data analysis and display Instrumentation Lab Digital imaging and image analysis Instrumentation Lab Taking stock material sizes into account when designing
Post-project discussion
The Archimedes-screw exercise exposes students to a much greater variety of tools, techniques and materials than did the rolling planter; these are listed in Table 3, along with areas of the project that focus on each learning objective. In addition, as students work on the device
instructors can draw their attention to the fundamental principles underlying its operation by asking such questions as: “What are the physical principles underlying the pumping mechanism?” “How does the screw’s pumping rate depend on pitch, drum angle, depth of filled reservoir, and other parameters?” and “Is there an arrangement of parameters that will cause the screw to fail entirely, and if so, what is the mechanism of failure?” Another important aspect of this project is that it is complex enough to call for the understanding and interpretation of truly technical shop drawings. We had already decided that it would be helpful for students to become familiar with shop drawings as part of this class, and the Archimedes screw provided an opportunity to give students experience reading and interpreting drawings as part of a fabrication project. Over the years we have also incorporated new tools and instruments into the project, as it became appropriate for students to consider using those tools and instruments in their own projects. For example, many of the acrylic components, which were cut using the band saw in the exercise’s original implementation, are now laser cut. Version 2.1, the sensor-equipped Archimedes screw A recent adaptation of the Archimedes-screw exercise was inspired by the current ready availability of plug-and-play sensors. In order to help students become familiar with the use of a variety of sensors, and with the notion of integrating sensor technology directly into their designs, we have added a fourth (two-hour-long) class session: an “instrumentation lab,” in which various sensors are installed on students’ Archimedes screws, and students use the data from these sensors to quantify ways in which pumping rate depends on critical parameters. Some elements of this session are shown in Figure 3. As part of the instrumentation lab, students also use digital imaging and image analysis to measure the rotation rate of their pump drums, along with force sensors to measure the mass of water being pumped up into the splash pan. At the end of the instrumentation lab, we open up the class’s entire “toolshed” of sensors, giving students the opportunity to experiment with pH sensors, thermistors, soil-moisture sensors, colorimeters and a variety of other easily-operated sensors that they might consider incorporating into their final projects. (We make available a variety of materials and setups for students to use in exploring the use of these sensors.) The instrumentation lab has helped us meet another instructional need as well. As mentioned above, students’ final class projects often involve designing and operating experimental apparatus or devices that demonstrate particular physical phenomena or processes. In previous years we have noticed that many students are not yet as well acquainted with appropriate methods of handling and displaying data as might be hoped. We had partially addressed the issue by adding a short class module on data-handling, but without concrete data to work with, the material seemed somewhat abstract to many students. We now incorporate the instrumentation lab directly into this module. Before the lab (but after the Archimedes-screw devices have been built), one of us gives specific instruction on working with and presenting observational data, including an introduction to various data-processing tools. Then, in the instrumentation lab, students acquire data on their own. As a follow-up, we work with students to help them interpret their data and present it most accurately and effectively. Since the data are the students’ own, and since they bear on questions about the Archimedes screw that the students find interesting, analyzing and displaying the data properly become priorities for the students, and the specificity and relevance of the analysis help make the educational message clearer.
Figure 3: Instrumentation lab, in which students use imaging tools and plug-and-play sensors to measure how changes in various parameters (e.g. pitch of hose on drum, angle at which drum descends into reservoir) affect pumping efficiency of Archimedes-screw devices. Here the devices are equipped with motorized drives to control the rotation rate of the drum and force-sensors to measure the mass of water pumped into the splash pan. Assessment The Archimedes-screw exercise was carried out in the fall semesters of academic years 2009-10 through 2013-14. During most years of this interval, roughly 24-30 students took the class. In the fall of 2009, 41 students enrolled; during that year (as during the fall of 2008) the class was taught in two separate sections. As before, the great majority of students taking the class were sophomores majoring in Civil and Environmental Engineering.
Assessment of the project, like that of the rolling-planter project, was based on:
1. Surveys distributed to students shortly after the project’s completion 2. Instructors’ observations of students’ comfort and skill with shop equipment and
materials 3. Instructors’ observations of the degree to which students incorporated materials and
processes from the exercise into their final class projects
4. Feedback from instructors who taught the next class in the sophomore design sequence, indicating the degree to which shop experiences in this class had prepared students for the work of that class.
Judging by the last three of these criteria, the Archimedes-screw exercise has been extremely successful. Again, as in the case of the rolling planter, survey data also support this conclusion (see Table 4). Table 4a: Survey-based assessment of Archimedes Screw exercise. Answers based on 5-point Likert scale.
Rate your skill level in the following areas before and after the project:
AverageBefore Project
% AnswersBelow 4 Before Project
AverageAfter
Project
% Answers Below 4
After Project
Response Rate (%)
Band Saw 2.7 68.7 4.2 16.4 89.3 Drill Press 2.8 61.2 4.2 13.4 89.3 Cordless Drill 3.2 51.5 4.4 7.4 91.3 Working with Acrylic 1.7 93.4 4.0 23.5 91.3 Jigsaw 2.2 77.4 3.6 39.1 89.3 Working with PVC 2.1 87.5 4.1 16.9 91.3 Working with Wood 3.2 54.8 4.3 8.1 90.6 Hardware (Screws, Nuts, Hinges, Brackets, Etc.)
3.5 46.9 4.4 6.2 90.4
Reading and Interpreting Shop Drawings
2.5 78.7 4.2 14.7 90.6
Measuring and Marking 3.6 42.5 4.5 5.3 90.4 Table 4b: Survey-based assessment of Archimedes Screw exercise; answers based on 5-point Likert scale.
Question Average Answer
Response Rate (%)
The project was interesting/fun 4.6 86.6
I am now better prepared to work in the lab and shop. 4.6 86.6
I have learned things about materials and machining operations that will be helpful when designing a project.
4.5 86.6
The pace of the project was (1=too slow; 3=just right; 5=too fast)
3.1 87.2
Conclusion and lessons learned We now conduct the Archimedes-screw exercise early in the semester, so that students will have time to absorb its lessons before they need to design their final projects. We alternate class
periods in which students work on the Archimedes-screw exercise and class periods in which they work on their theoretical design projects. Then, as the students develop proposals for their final design/prototype/fabricate projects, they have direct access to the knowledge and skills they have gained by participating in the shop exercise. Since the advent of the Archimedes-screw exercise, we have seen students incorporate a much wider variety of materials and techniques into their final projects, such as PVC tubing (for structural as well as hydraulic uses), larger-scale plywood structures, watertight joints between flexible hose and acrylic, and precision laser-cutting of parts. Survey data and observations of students at work show that students experience strong learning gains in all our targeted areas, and they often become deeply engaged in trying to understand the surprisingly complex physics of the Archimedes screw itself. The process of developing, implementing and revising this exercise has involved its own learning curve, and it has provided us with many lessons that might be of use to other instructors who would like to develop similar exercises for their own classes. Some of the most important of these have been:
Develop an exercise suited to the level of sophistication desired in students’ own projects. Students—largely unconsciously—take this exercise as a model of the kind of work they might be expected to do on their own.
Be sure to prototype the large-scale process, as well as the product students will build during the exercise. If the exercise involves a number of complex steps, some of which must be executed in a particular order, it is extremely valuable try the process out multiple times—to run a group, or several groups, of people through the entire process in order to identify pinch-points, rate-limiting steps, and stations that are likely to become too crowded. It is important to equip these test cohorts with whatever written instructions and drawings one intends to give the students, in order to prototype those as well. Process-prototyping also makes it possible to estimate accurately the time necessary for each stage of the project, and to schedule class sessions accordingly. In addition, these process-prototyping sessions can serve another purpose, by making TAs and other assistants deeply familiar with the exercise procedures, so that they can more effectively guide students through them.
Provide an adequate number of class periods for students to complete the exercise. It can seem as if such an exercise absorbs a large amount of precious time, but it more than pays for itself, both in the speed and efficiency with which students later work on their own in the shop, and in the sophistication and variety of their later class projects.
Assess students’ skill and confidence in the shop before engaging them in the exercise, and create teams that include students of varied ability; otherwise, teams consisting only of skilled or confident students will move quickly through the exercise, while others may struggle to keep up. It is important, however, to stress that the more experienced students must step back as appropriate in order to enable their partners to participate fully and acquire the relevant experience and skill.
We have found it most efficient to create a process that limits the amount of movement around the shop required of students. In the early years of this exercise we prepared individual stations for each operation (e.g. acrylic joining, measuring and marking wood,
etc.) and asked student teams to move station-to-station to complete their tasks. We have since moved toward a system in which each student team has a “home base,” to which students or instructors bring whatever tools and materials are required for the next operation. In addition, each student team is now equipped with a “parts kit” for the project, instead of having to select various parts from supply areas in the shop. These might seem to be minor changes, but they have eliminated a significant amount of confusion, misplaced project parts, etc. (Of course, some separate workstations cannot be eliminated; for example, for stages that require the drill press or band saw, students will need to move to those areas of the shop.)
To the extent possible, make sure that members of student teams do not divide up project tasks and complete them separately. Part of the point of the exercise is to ensure that each student gets exposure to each tool, technique or material, and this will not happen if students carry out separate operations. To prevent this, it is helpful to include a number of steps that require multiple students to work together (e.g. one student holding acrylic components in place while another student applies solvent, with students trading off to exchange tasks for the next joint to be made).
Choose with care the tools and materials featured in the exercise. We have found that whenever we incorporate a new tool, material or technique into the exercise, that tool, material or technique finds its way into a large number of the students’ final design projects. That is generally a good thing, since part of the point of the exercise is to broaden students’ horizons concerning the tools and materials available to them, but sometimes it can be difficult to induce students to see beyond the elements they have encountered in the shop exercise, or to see when a given technique, no matter how interesting in itself, is simply the wrong one for their chosen ends. (For example, in the year we first incorporated a demonstration of 3-D printing into the exercise, a number of student teams decided to 3-D print components that might better have been fabricated via more conventional methods.)
In developing and refining an exercise, maintain a list of learning goals that the instructors would like the students to achieve, and use that list as a filter to eliminate project ideas that, although interesting in themselves, take the focus away from the exercise’s ultimate goals.
It will likely not be possible to allow enough time for students to build the entire project from raw stock materials. Some parts will probably need to be pre-cut, others might need to be marked in advance, etc. This is unfortunate, but it is necessary in order to focus students on the specific learning goals of the exercise. They can experience the process of building from scratch afterwards, as they create their own class projects.
Similarly, it will not be possible in this exercise for students to learn all they need to know in order to operate certain tools and machines. The exercise sets the stage for more detailed point-of-use instruction to be given later, adapted to each student’s needs and experience.
Update the exercise in order to incorporate any new tools and techniques that become available to students. The exercise, no matter how effective as it is, can never be viewed as a finished product—one must always be ready to adapt it to suit new circumstances and learning goals.
A note concerning Appendices: For those who wish to incorporate the Archimedes-screw exercise directly into their own classes, or to adapt the project for their own use, in Appendices A and B we have included the detailed drawings and instructions that we distribute to students, as well as specific schedules, notes, and lists of parts, hardware and materials necessary for administering the exercise. We will also be happy to provide further guidance and assistance as may be required. Acknowledgments We are grateful to the many students and teaching assistants who participated in or contributed to the development of this project, and in particular to Denis Terwagne and Stephen Morgan, who played important roles in the development of the Instrumentation Lab. We also thank the MIT Department of Civil and Environmental Engineering for financial support. P.M.R. thanks the U.S. National Science Foundation for support under awards CMMI-1129894 and CMMI-1351449 (CAREER). Bibliography [1] G. Muller and J. Senior,“Simplified theory of Archimedean screws”, Journal of Hydraulic Research, 47(5), 666–669 (2009). [2] C. Rorres, “The Turn Of The Screw: Optimal Design Of An Archimedes Screw”, Journal of Hydraulic Engineering, 126(1), 72–80 (2000). [3] M. Lyons and W. D. Lubitz, “Archimedes Screws for Microhydro Power Generation”, Proceedings of the ASME 2013 7th International Conference on Energy Sustainability & 11th Fuel Cell Science, Engineering and Technology Conference ESFuelCell2013, ES-FuelCell2013-18067, pp. 1-7, Minneapolis, MN (2013) [4] D. M. Nuernbergk and C. Rorres, “Analytical Model for Water Inflow of an Archimedes Screw Used in Hydropower Generation ”, Journal of Hydraulic Engineering, 139(2), 213–220 (2013). [5] C. D. McNabb, C. R. Liston and S. M. Borthwick, “Passage of Juvenile Chinook Salmon and other Fish Species through Archimedes Lifts and a Hidrostal Pump at Red Bluff, California”, Transactions of the American Fisheries Society, 132(2), 326-334 (2003).
Appendix A: Plans and Instructions for Archimedes Screw Exercise, As Distributed to Students
Schedule
Operation Drawing Name Drawing No. Machines Tools Supplies
cut Splash Pan parts Assembly - Splash Pan 2-A laser cutter
fuse Splash Pan Assembly - Splash Pan 2-A dispensing syringe acrylic solvent
fuse Reservoir Assembly - Reservoir 1-A 1/8" x 1" spacers paper towels
1/2" x 1" spacers
file
clean and mark Center Block Center Block 6-1 combination square pencil
clean and mark Clamp Blocks Clamp Block 6-2 ruler sandpaper
clean and mark Clamp Board Clamp Board 7-1 sanding block
clean and mark Pan Support Pan Support 7-2
clean Base (no marking needed at this time)
Operation Drawing Name Drawing No. Machines Tools Supplies
seal Reservoir Assembly - Reservoir 1-A silicone sealant
seal Splash Pan Assembly - Splash Pan 2-A paper towels
assemble and clean Axle Assembly - Axle 3-A tubing cutter PVC cement
assemble and clean Pump Assembly - Pump (1) 4-A1 file pencil
assemble Crank Assembly - Crank 5-A deburring tool paper towels
tape measure
ruler
drill Center Block Center Block 6-1 drill press drill press vise
drill Clamp Blocks Clamp Block 6-2 23/64" drill bit
25/64" drill bit
7/16" drill bit
7/8" spade bit
cut slots in Clamp Board Clamp Board 7-1 jig saw jig saw blades
hand drill pencil
7/16" spade bit
ruler
cut notch in Clamp Board Clamp Board 7-1 band saw
cut notch in Pan Support Pan Support 7-2
drill holes in Pan Support Pan Support 7-2 hand drill backing board
5/32" drill bit
Operation Drawing Name Drawing No. Machines Tools Supplies
break sharp edges on Reservoir and Splash Pan sanding block sandpaper
file
tap hole in Reservoir Assembly - Reservoir 1-A hand drill pencil
drill and tap holes in Pump Assembly - Pump (1) 4-A1 #29 drill bit marker
#8 -32 tap
tap wrench
tape measure
install Drain Tube in Reservoir Assembly - Final 8-A ruler
attach Tubing to Pump Drum Assembly - Pump (2) 4-A2 shears
Phillips screwdriver
cut and chamfer Pivot Shafts Assembly - Bearing 6-A horiz. band saw ruler marker
insert Pivot Shafts into Center Block Assembly - Bearing 6-A belt sander hammer
attach Feet to Base Assembly - Frame (1) 7-A1 hand drill 5/8" spacers
attach Hinges to Base Assembly - Frame (1) 7-A1 5/64" drill bit pencil
attach Pan Support to Base Assembly - Frame (1) 7-A1 Phillips screwdriver
attach Reservoir to Base Assembly - Frame (2) 7-A2 Phillips driver bit
attach Clamp Board to Base Assembly - Frame (2) 7-A2 5/16" wrench
combination square
ruler
install Tee Nuts in Clamp Blocks Assembly - Final 8-A hammer
assemble Pump Assembly - Final 8-A
install Pump in Frame Assembly - Final 8-A
SESSION 1
SESSION 2
SESSION 3
Parts and Drawings
Part Material Size Qty. Drawing Name Drawing No.
ReservoirBottom acrylic 1/4" x 11-3/4" x 11-3/4" 1Side acrylic 1/4" x 2-7/8" x 11-3/4" 2End acrylic 1/4" x 2-7/8" x 9-1/4" 2
Assembly - Reservoir 1-A
Splash PanBottom acrylic 1/8" x 7" x 9" 1Side acrylic 1/8" x 1" x 8-7/8" 2Drip End acrylic 1/8" x 1-1/4" x 7" 1End acrylic 1/8" x 1" x 7" 1Foot acrylic 1/8" x 1/2" x 7" 1
Assembly - Splash Pan 2-A
AxleCenter Rod PVC pipe 1" x 6" 1Stop PVC pipe 1" x 3-5/8" 2
Assembly - Axle 3-A
PumpDrum PVC pipe 1-1/4" x 19-3/4" 1Shaft PVC pipe 1/2" x 3" 1
Assembly - Pump (1) 4-A1Assembly - Pump (2) 4-A2
CrankCoupler PVC pipe 1/2" x 1-3/8" 1
Assembly - Crank 5-A
BearingCenter Block wood 1-1/2" x 2-1/2" x 4" 1 Center Block 6-1Clamp Block wood 1-1/2" x 2-1/2" x 3-1/2" 2 Clamp Block 6-2Pivot Shaft stainless steel rod 3/8" dia. x 3-1/4" 2
Assembly - Bearing 6-A
FrameBase plywood 3/4" x 11-3/4" x 23-3/4" 1Clamp Board plywood 1/2" x 11-3/4" x 18" 1 Clamp Board 7-1Pan Support plywood 1/2" x 3-3/4" x 10" 1 Pan Support 7-2
Assembly - Frame (1) 7-A1Assembly - Frame (2) 7-A2
Assembly - Final 8-A
Appendix B: Additional Project Documents, for Use by Teaching Staff (Quantities sufficient for 12 teams of students @ 2 students per team; table setups
sufficient for up to 15 teams)
Sessions
Station qty. Items / Station qty. tot. Station qty. Items / Station qty. tot. Station qty. Items / Station qty. tot.
Laser 1 table 8 tape measure 2 16 table 8 hand drill 2 16
(2 teams pencil 4 32 (2 teams 5/64" drill bit 2 16
per table) 6" ruler 2 16 per table) #29 drill bit 1 8
table 8 pencil 4 32 12" ruler 2 16 #8 -32 tap 1 8
(2 teams 6" ruler 2 16 tap wrench 1 8
per table) 12" ruler 2 16 Phillips screwdriver 2 16
table 1 jig saw 2 2 Phillips driver bit 2 16
jig saw blades 4 4 5/16" wrench 1 8
set 1 dispensing syringe 10 10 hand drill 2 2 combination square 2 16
acrylic solvent 1 1 7/16" spade bit 2 2 6" ruler 2 16
1/8" x 1" x 8" spacer 10 10 12" ruler 2 2 12" ruler 2 16
1/2" x 1" x 8" spacer 15 15 pencil 2 2 tape measure 2 16
paper towels (pack) 2 2 hammer 1 8
file 8 8 pencil 4 32
band saw 2 marker 1 8
set 1 combination square 10 10 5/8" thick spacer 4 32
sanding block 10 10 file 1 8
drill press 4 drill press vise 1 4 sanding block 2 16
23/64" drill bit 1 1
(bits are one 25/64" drill bit 1 1
per drill press) 7/16" drill bit 1 1 shop 1 horizontal band saw 1 1
7/8" spade bit 1 1 belt sander 1 1
ruler 2 2
marker 2 2
set 1 combination square 10 10
sanding block 10 10
table 1 shears 2 2
set 1 silicone sealant 6 6 pouring pails 8 8
paper towels (pack) 1 1 3/8" -16 x 10" rod 2 2
mallet 1 1
set 1 tubing cutter 6 6 (TEE nut extractor)
deburring tool 6 6
file 6 6 set 1 cloth 6 6
PVC cement 4 4 mop 1 1
paper towels (pack) 1 1
set 2 hand drill 1 2
5/32" drill bit 1 2
backing board 1 2
Intro: 10 min. 1:05 - 1:15 Intro: 10 min. Intro: 10 min.
Round 1: 25 min. 1:15 - 1:40 Start with: Work flow is free form as most tasks are done at
Grp. A 5 teams fuse reservoir 6 teams silicone benches. Just need to make sure that the pivot
Grp. B 5 teams fuse reservoir 5 teams PVC shafts all get cut - spread out teams over the
Grp. C 5 teams laser cut splash pan 2 teams jig saw --> band saw class period.
2 teams blocks
Round 2: 25 min. 1:40 - 2:05
Grp. A 5 teams laser cut splash pan 1 instructor - silicone and pan support holes
Grp. B 5 teams clean and mark 1 instructor - PVC
Grp. C 5 teams fuse reservoir 1 instructor band saw
1 instructor - jig saw
Round 3: 25 min. 2:05 - 2:30 1 instructor - drill press
Grp. A 5 teams fuse splash pan
Grp. B 5 teams laser cut splash pan Teams should not leave home tables until sent to
Grp. C 5 teams fuse splash pan a station by an instructor.
Round 4: 25 min. 2:30 - 2:55 Instructors assigned to stations must
Grp. A 5 teams clean and mark make sure that there is a consistent flow so
Grp. B 5 teams fuse splash pan all teams finish the task.
Grp. C 5 teams clean and mark
Tool Table (Lab)
Tool Table (Lab)
Team Work Sations (Lab)
Session 3Session 1 Session 2
Team Work Sations (Lab)Cut Splash Pan (Fab Lab) Team Work Sations (Lab)
Slots (1-063)
Notches (Shop)
Bearing Block Holes (Shop)
Tool Table (Lab)
Pivot Shafts (Shop)
Survey students for skill level to avoid excessively slow teams
SESSION 1This is an introduction and flavor of what can be done and how to do it
Work together as much as possible
Specific instruction will be given at each station
Read all the instructions for an operation before beginning
Staff will clean up on Archimedes Project days; in future it is students' responsibility
Label your materials
Use cabinets to store project
SESSION 2Work together on tasks
Leave instructions at home base (drawings will be at stations if needed)
Do not go to a station until sent by an instructor
Explain the purpose of the silicone sealant
Perform any filing on acrylic before applying sealant
Be careful to drill correct holes in blocks - mark holes sizes on blocks
Drill presses are all set up for depth; do not adjust
Show twist and spade bits (1/2" each, 1-1/2" each, long each, 5" hole saw)
Show difference between fittings and pipe
Keep materials not being worked on in cabinets
SESSION 3Most operations need to be done in the order listed in the schedule
Read all the instructions for an operation before beginning
Only task not at tables is cutting and sanding pivot shafts
Do not use band saws to cut pivot shafts; wait for instructor
Don’t hammer the pivot shafts in past the bottom of hole
Do not drill holes in the tables
Explain the proper chucking of drill bits and drive bits
Explain the difference between tapping and machine screws
Explain the difference between flat head and pan head screws
Explain how a thread is tapped
Explain use of washers
Be creative with wrapping tubing
Tools
Supplies Qty. Supplier Part # Price Cost SessionRTV silicone sealant 108 6 McMaster-Carr 7545A471 5.37$ 32.22$ 2acrylic solvent, Weld-on #3 1 McMaster-Carr 7528A13 15.95$ 15.95$ 1PVC cement 2 McMaster-Carr 74605A81 4.37$ 8.74$ 2sandpaper, 2-3/4" x 9", grit 120, 15 pk. 2 McMaster-Carr 4731A52 2.84$ 5.68$ 1,2,3pencil (pkg. 12) 2 Staples 434931 3.28$ 6.56$ 1,2,3Sharpie markers (pkg. 12) 2 McMaster-Carr 1661T11 12.77$ 25.54$ 3plastic bags 2" x 3" (100) 1 McMaster-Carr 1959T11 1.62$ 1.62$ 3plastic bags 9" x 12" (50) 1 McMaster-Carr 1959T48 9.08$ 9.08$ 1,2,3terry cloth rags (5 lbs) 1 McMaster-Carr 7366T19 23.90$ 23.90$ 3backing boards 2,35/8" thick spacers 3paper towels 1,2
Tools Qty. Supplier Part # Price Cost Sessionhand drill 12 2,3jig saw 2 2jig saw blades (pk, 2) 2 McMaster-Carr 4131A93 5.69$ 11.38$ 2dispensing syringe, 5 mL 12 VWR 20068-056 9.52$ 114.24$ 1dispensing needle (50) 1 McMaster-Carr 75165A758 14.41$ 14.41$ 1needle covers (50) 1 McMaster-Carr 75165A18 8.31$ 8.31$ 1#8 -32 tap 6 McMaster-Carr 2523A447 5.26$ 31.56$ 3tap wrench 6 McMaster-Carr 2546A23 15.07$ 90.42$ 3combination square 12 McMaster-Carr 2007A9 10.62$ 127.44$ 1,2,312" ruler 12 McMaster-Carr 2014A11 2.56$ 30.72$ 1,2,36" ruler 12 McMaster-Carr 2388A52 3.47$ 41.64$ 1,2,416' tape measure 12 McMaster-Carr 19175A62 9.67$ 116.04$ 2,3tubing cutter 6 McMaster-Carr 2527A11 52.41$ 314.46$ 2replacement wheel (same as original) 6 McMaster-Carr 2527A15 12.76$ 76.56$ 25/64" drill bit 12 McMaster-Carr 8870A15 0.88$ 10.56$ 3#29 drill bit 6 McMaster-Carr 30585A42 1.12$ 6.72$ 35/32" drill bit 2 223/64" drill bit 1 225/64" drill bit 1 27/16" drill bit 1 27/16" spade bit 2 McMaster-Carr 2894A64 2.75$ 5.50$ 27/8" spade bit 1 McMaster-Carr 2894A57 3.09$ 3.09$ 2drill press vise 4 2hammer 4 3#2 Phillips screwdriver 12 Home Depot 681-410 3#2 Phillips driver bit 12 McMaster-Carr 5751A26 0.75$ 9.00$ 35/16" combination wrench 6 Grainger 4AJ99 4.92$ 29.52$ 3file 6 McMaster-Carr 4225A23 8.07$ 48.42$ 1,2,3file handle 6 McMaster-Carr 42215A21 4.12$ 24.72$ 1,2,4shears 2 McMaster-Carr 7102A15 16.25$ 32.50$ 3sanding block 12 McMaster-Carr 4731A2 3.57$ 42.84$ 1,2deburring tool 4 McMaster-Carr 4289A33 8.98$ 35.92$ 2deburring blades 4 McMaster-Carr 4289A61 1.80$ 7.20$ 2bench duster 4 McMaster-Carr 7159T13 14.29$ 57.16$ 1,2,3dust pan 4 McMaster-Carr 7250T13 4.68$ 18.72$ 1,2,3safety glasses (clear) 24 Grainger 4FE54 3.94$ 94.56$ 1,2,3pouring pails 4 McMaster-Carr 4485T11 7.74$ 30.96$ 31/4" x 1" x 8" aluminum spacer 11/2" x 1" x 8" aluminum spacer 1
Machines Qty. Supplier Part # Price Cost Sessionband saw 2 2drill press 4 2belt sander 1 3horizontal band saw 1 3
Materials
Part Material Size Qty. Unit Total Session
ReservoirStock acrylic 1/4" x 12" x 24" 1 each 12 1
Splash PanStock acrylic 1/8" x 12" x 12" 1 each 12 1
AxleRod and Stop PVC pipe 1" x 13-1/4" 1 inch 12 2
PumpDrum PVC pipe 1-1/4" x 19-3/4" 1 each 12 2Shaft PVC pipe 1/2" x 3" 1 each 12 2
CrankCoupler PVC pipe 1/2" x 1-3/8" 1 inch 12 2
BearingCenter Block wood 1-1/2" x 2-1/2" x 4" 1 each 12 2Clamp Block wood 1-1/2" x 2-1/2" x 3-1/2" 2 each 24 2Pivot Shaft stainless steel rod 3/8" stock rod 7 inch 84 3
FrameBase plywood 3/4" x 11-3/4" x 23-3/4" 1 each 12 1Clamp Board plywood 1/2" x 11-3/4" x 18" 1 each 12 1Pan Support plywood 1/2" x 3-3/4" x 10" 1 each 12 1
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Inst
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Lab