Some Disassembly Required

BY CORINNA WU

Reverse engineering – taking products apart to learn how they work – can be a valuable design training exercise.

When Apple’s iPhone first came out in June 2007, eager customers lined up for days to get their hands on one. But not everyone shelled out $599 so they could call friends and surf the Web on the portable device: Some people bought one just so they could take it apart. They immediately started blogging about the components and how the devices were assembled, the design choices Apple made and what the parts cost.

These curious gadget freaks were engaging in reverse engineering, a common practice in industry wherein companies tear down competitors’ products in order to figure out their secrets.

Over the past two decades, engineering professors have been bringing the practice into the classroom. Currently, about 30 universities have integrated the method into their teaching, says Sheri Sheppard, a professor of mechanical engineering and co-director of the Center for Design Research at Stanford University. By disassembling simple machines like bicycles, kitchen appliances, power tools and toys, students get hands-on experience with various parts that helps them when they begin designing products of their own.

Sheppard’s first experience with reverse engineering came during her graduate school days at the University of Michigan. She had a job at Chrysler, and the company sent its new hires to mechanics school for three months. There, she learned how to take apart and rebuild engines, transmissions, and brake systems, something she had not done as an undergraduate. “It made me realize how much you learn through the kinesthetics of touching stuff,” she says. “Your ability to reason about those things in the abstract is so much more powerful if you’ve actually touched the systems on which you’re going to do engineering.”

Bicycles and Fishing Reels

When she joined the Stanford faculty, Sheppard began integrating reverse engineering into her freshman- and sophomore-level classes. She called it “mechanical dissection” to make an analogy to medicine. Instead of dissecting cadavers, though, the engineering students took apart bicycles and fishing reels.

Sheppard also encouraged the students to see the products through the eyes of the consumer. For example, she would invite a skilled angler to teach the students how to use the reel, and they’d try out different brands. That way, once the students took the reels apart, they could see that the “same external function can be gotten with different mechanisms inside,” she says.

Sometimes, students learn the opposite lesson from their teardowns. Tim Simpson, a mechanical and industrial engineering professor and director of the Learning Factory at Pennsylvania State University, has his students take apart families of products, such as coffeemakers and single-use cameras. The students are often surprised to see that the products are very similar inside — the same basic structure with different features added.

For many engineering students, a classroom exercise in mechanical dissection might be the first time they’ve ever taken something apart. Nowadays, fewer students enter college with any hands-on experience with technology, Simpson says. They’ve spent most of their time on the computer and have lost that intuitive sense of working with tangible things.

As such, students must learn how to dissect a gadget without destroying it. A reverse engineering exercise gives students the opportunity to learn how to measure performance, make drawings and sketches, and communicate technical information. Sheppard asks her students to write an instruction manual for the product, which then gets critiqued by non-engineering students.

Reassembly, Redesign

And in the end, the students must put the products back together. When his students take apart engines and bicycles, Simpson says, “the final exam is that the bike has to be ride-able, and the engine has to start again.” The reassembled products are used again for the following year’s classes.

Sheppard feels that having to reassemble the products fosters a pride in workmanship. “I really stress respect for stuff and giving it back to me in better condition than you received it,” she says. “If you recognize that you’ll have to put it back together, you think more deeply about how you take it apart.”

In Robert Stone’s senior-level design methods course at the Missouri University of Science and Technology in Rolla, students not only disassemble products but also redesign them. They choose a component that can be improved, prototype a new version of that part, and put it back in. For example, one team designed wider openings for a vacuum cleaner so it could suck in debris from corners. Another rearranged the controls on a bagel toaster so it was easier to use and adjusted its timing cycle so it toasted better.

“It’s an opportunity to climb into the head of whoever built the thing, which is always informative,” says Kerry Poppa, who graduated from Missouri S&T’s interdisciplinary engineering program in 2007, focusing on product design. “You always find things you didn’t expect to find.”

Analyzing a product in detail lays bare the design choices and tradeoffs that are made, not just for engineering reasons but for targeting particular markets. “You get an appreciation for the fact that engineered products are simultaneously much better and much worse than you expected,” Poppa says. “It’s interesting to see inside things and say, ‘These two are 98 percent the same, but I perceive this one to be a very high quality product and this one to be a very cheap product,’ and think about why.”

Giving students a product to improve upon helps students see the endpoint of design, says Kris Wood, a professor of mechanical engineering at the University of Texas at Austin who wrote a textbook on reverse engineering with co-author Kevin Otto, formerly of MIT. “When you’re able to start with a product and evolve it, which happens in a lot of companies, you’re able to see the results quicker, which helps students to learn,” he says. In a traditional design course, where students create something from scratch, “nine months later you’re finally building your prototypes in a lot of classes. We’re able to see those results in weeks or a month or two,” Wood says.

Teaching product dissection requires workspace, storage space, tools, and extra help from teaching assistants – the challenges of running any type of lab component, Sheppard says. And of course, there is the cost of all the products students will be tearing down. Campus police departments are good sources of free, abandoned bikes. Companies that make power tools, cameras, small appliances, or toys sometimes donate products to the classes. With a $20-per-student budget, a trip to WalMart can yield many interesting things to reverse-engineer.

“The reality is that very little design is actually new design.”

—SHERI SHEPPARD Mechanical Engineering Professor at Stanford University

If a lack of resources prevents students from doing a hands-on exercise, a product dissection can be done as a demonstration in front of the class. For larger, more expensive products like a refrigerator, car – even an airplane — the hope is to develop virtual representations for students to analyze, Simpson says. “It would allow you to span the scale from very small, cheap, low-end consumer goods to a billion-dollar system,” Simpson says.

Last year, Simpson and Stone received grants from the National Science Foundation to capture product dissection case studies and store them online. The repository, in the form of a wiki (http:http://gicl.cs.drexel.edu/wiki/Category:Disassembly_notes), contains photos, 3D models, diagrams, and documentation for various products. The case studies could be used as reference materials for actual hands-on dissections or simply studied as virtual dissections.

Reverse engineering has long been upheld as a legitimate way to reveal a product’s trade secrets. “As long as you’re not trying to reproduce it or make it yourself, you’re not infringing on anybody’s copyright or intellectual property,” Simpson says. Besides, taking something apart doesn’t provide all the information needed to recreate it. “We can measure a part and see what the final fabricated dimensions are, but we don’t know what the tolerances are,” he says. “We can take a guess at what the material is, but we don’t know exactly.”

Mechanical dissection doesn’t replace traditional design pedagogies, but instead complements them. “The reality is that very little design is actually new design,” Sheppard says. “Very good designers have this catalog in their brain of stuff – of mechanisms, of devices, of machine elements.” Dissection helps students build that mental catalog, which they can order from in the future.

Corinna Wu is a freelance writer based in Oakland, Calif.