Reverse engineering involves taking an object apart and figuring out how it works. Sounds like something a manufacturer would do in order to rip off a competitor's design, skip research and development, and get to market right away? Not anymore. These days, reverse engineering is gaining respectability as well as sophistication. It is considered the speediest way to translate the dimensions of a physical model or shape into digital files, thus allowing engineers to create manufacturing, machining or repair plans for it. In other words, the practice is not just about dismantling products in order to analyze them but bringing objects into the digital realm in order to fix or improve them.

Reverse engineering owes its newfound respectability to the increasing popularity of rapid prototyping—the process of constructing complex three-dimensional models and prototypes from computer-aided design (CAD) files. Original equipment manufacturers (OEMs), manufacturers, fabricators and service shops have found that reverse engineering can accelerate rapid prototyping, as well as other internal processes. As a result, the practice has shed its reputation as a copycat's technique and has become recognized for the benefits it can bring to applications that do not involve intellectual property rights.

The first step in reverse engineering is obtaining the physical measurements of an object, be it a plastic frame or a boat hull. These measurements are then recorded in a digital medium (a platform that's compatible with CAD) as an image composed of dots, streaming lines or wire frames. Next, this image is fine-tuned using one or more software packages such as surfacing, stress analysis, plant layout or product flow. Current software allows images to be reversed, doubled or repositioned, letting automotive model shops, for example, digitize just one fender of a model and then quickly generate its mirror-image fender.

Reverse engineering applications include design, development, tool making, repair, fabrication and manufacturing. To create a new design, for instance, engineers can digitally capture the dimensions of a mechanical model and then enhance it using surfacing, ergonomic and other programs. Reverse engineering is also used to modify a product. For example, engineers could convert a mounting or mating structure into a drawing file and then make adjustments to it in CAD or similar programs. For one sheet metal fabricator, the technology's capabilities come in handy when it modifies military vehicles so that they can carry external items, including backup gasoline tanks. The fabricator obtains a digital rendering of the surface where a bracket is to be attached and transports this image into its design software, where it helps build the bracket.

Also benefiting from reverse engineering is NASCAR team, Richard Childress Racing (RCR). RCR engineers relied on reverse engineering to create the first 3D digital model of General Motors' SB2 (Small Block, Second-Generation) engine block—not an easy task considering there were only 2D prints available. "It would probably have taken several months if we had to model the block directly, and I'm not sure we would have been able to capture the complexity of the actual cast surfaces," Clifton Kiziah, the senior engineer who led the project, tells Machine Design. With this 3D model, the NASCAR team will be able to perform engineering analysis on the standard engine block. It will work to optimize cooling as well as maximize horsepower and torque. In short, reverse engineering will pave the way for future redesigns and enhancements.

Another application in which reverse engineering excels is repair. In particular, the technology can recreate parts for which no drawings are available. In some cases, the equipment to be fixed is so old that the original drawings have been misplaced, and in other cases, no drawings were made in the first place. For example, when a blade broke off an impeller for an air supply compressor, plant engineers were able to reverse engineer a solution. Instead of waiting eight months for the manufacturer to send them a new impeller, they took the dimensions of the original to digitally document the locations of the blades, including the one that cracked off. They then downloaded the data into a CAM (computer-aided manufacturing) program and created a machining plan to make the new impeller. In three weeks, they completed the project.

In addition, the technology is proving useful in tool making—where it could create or adjust tooling—and in product testing—where it has allowed fabricators to dramatically speed up the process of evaluating designs. In short, reverse engineering is claiming more and more applications and in the process, gaining the respect that once eluded it.

Sources:

Reverse Engineering
Shawn Mymudes
Tooling & Production, April 2004
www.manufacturingcenter.com/tooling/archives/0404/0404_reverse.asp

Reverse Engineering Fine-Tunes NASCAR Engine
Bob Cramblitt
Machine Design, February 5, 2004
www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=56597&strSite=MDSite