Integrating Reverse Engineering into Core Design
Reverse engineering has always been an important activity in design. The practice, in which engineers deconstruct and analyze an existing physical thing to understand how it was designed, has always provided a means to reproduce products. Some teams use it to replicate competitive products. Others employ it to recreate components for which no engineering documentation exists. Still others leverage as a means to identify the root cause of failures. It gives engineering organizations an important capability. Despite the significant role that reverse engineering plays in design, its integration into modern digital development processes has been lacking. Engineers must often turn to a variety of complicated and un-integrated software applications to complete the job. A large amount of friction in that digital workflow undermines the effectiveness of reverse engineering activities.
That friction erodes engineers’ productivity and limits the time they can devote to design and development. However, new technology is promising to eliminate the digital friction associated with reverse engineering. Software tools that provide the right mix of capabilities to complete the entire
workflow in a single environment are emerging. That, in turn, allows engineers to recoup their productivity. Therein lies the focus of this eBook. It examines the details of reverse engineering and discusses how the process fits into concept design, detailed design, prototyping, and testing. It also
delves into the traditional and progressive digital solutions that support reverse engineering, highlighting their pros and cons. Reverse engineering is a critical part of design. It’s time the proper tools were available to support it.
Reverse Engineering in the Development Process
Before discussing the technology used to support reverse engineering, it is important to understand the basics of reverse engineering. This section covers how and why it is used in the development process, explains technical issues that need to be considered, and explores how it is used in the concept design, detailed design, prototyping, and testing stages.
Applications of Reverse Engineering
There are numerous circumstances during the development process in which reverse engineering is beneficial, despite the friction in executing its digital workflow. The common thread running through such cases is that the organization does not have engineering documentation. Common reasons for this include the following:
- The product or component was developed before good configuration and control practices were put into place.
- The product or component was developed by a company that has since been acquired, and the documentation was lost or misplaced during the transition.
- If the product or component was part of a startup,documentation may have never been developed.
- The product or component may belong to a competitor,either still operating or not.
- A organically shaped design is first developed physically and needs to be converted into a digital definition.
The reasons an engineering organization may need to leverage for reverse engineering in their development process can vary widely, including the following:
- A product or component operating in a longstanding operating cycle has broken or must be replaced. The organization must replicate the existing product or component as a replacement. Alternatively, the organization needs to understand the root cause of the failure to avoid issues in the future.
- The organization aims to develop the next generation of an existing product or component. They need a digital representation of the existing item to use as the starting point for a new design.
The Two Application Solution
In Concept Design, Detailed Design, and Prototyping and Testing, reverse engineering is an important core design activity. However, the traditional technologies used to support reverse engineering, an un-integrated couple of software applications, inherently have high amounts of friction in the digital workflow.
Two Geometry Types, Three Modeling Types
In general, traditional geometry modeling takes one of two forms: Parametric or Direct. Parametric Modeling can be used to create a model feature-by-feature, using parametric dimensional controls. Direct Modeling modifies existing geometry by pushing, pulling, or dragging it. Both of these modeling approaches work with ‘boundary representations,’ in which the geometry is represented by flat or smoothly curved surfaces.
Mesh geometry, by contrast, contains a cloud of points representing the outer surface of a design. Some CAD applications turn this into solid geometry by creating planar triangles or trapezoids and stitching them together into a ‘watertight’ solid. Facet Modeling lets engineers tweak the quality of the resulting mesh as well as modify that geometry by adding or removing material.
As noted earlier, there are cases where engineers need to develop smoothly rounded geometry as well as Mesh Geometry. In Concept Design, engineers need to work with the sketches and space claims alongside the Mesh Geometry of scanned components. In Detailed Design, they need to create detailed 3D Models taking Mesh Geometry into account. In Prototyping and Testing, they need to quickly produce components from these boundary representations and Mesh Geometry.
The Two Application Solution
Traditional CAD applications used for building 3D models and other items often use some combination of Parametric and Direct Modeling, both of which result in boundary representations. Together, this powerful combination of modeling tools can be used quickly and easily to develop design concepts and detailed designs, and to produce physical components. Unfortunately, very few offer Facet Modeling alongside these conventional capabilities.
Because most CAD applications are unable to work with Mesh Geometry, engineers must turn to other solutions to get the job done. Some standalone specialty applications, typically ones that offer the laser scanning hardware, provide a CAD-like application that includes Facet Modeling. Theoretically, engineers can use both traditional CAD applications and these specialty CAD-like applications together. However, there are numerous drawbacks to this scenario.
Exchanging Design Data
If you are familiar with the exchange of geometry between CAD applications, then you are likely familiar with the issues here. Moving a model from one software application to another often results in misaligned or missing surfaces, lines, or points. This ‘breaks’ the model, because it no longer represents the design, and engineers must fix these sorts of problems every time geometry moves from one type of software to another.
Moving geometry back and forth between traditional CAD applications and specialty CAD-like applications is no different. This hand off is subject to the same issues. The result is more time lost for the engineer and a likely setback for the development project.
It is possible for engineers to use traditional CAD applications alongside specialty CAD-like applications to enable reverse engineering, but not without significant friction in the digital workflow. It does not allow engineers to use Parametric, Direct, and Facet Modeling interchangeably, which constrains their design freedom. It also translates into a significant amount of time to fix design data exchanged between these two software applications. While alternative solutions would have been preferred for years, this was the only means of running reverse engineering processes in product development.
The Single Application Solution
In the past year, new technology has emerged that enables faster and easier reverse engineering in the development process. Some CAD applications have expanded their capabilities to include Parametric, Direct, and Facet Modeling. Beyond importing point cloud data and creating the resulting Mesh Geometry, there are critical implications for the application of reverse engineering. When engineers need to create boundary representation geometry from the scan data, the workflow gets simpler. All modeling capabilities are in a single environment, which means engineers can use the right tool for the situation at hand.
In another interesting case, engineers don’t necessarily need to transform scanned components into boundary representation geometry. Facet Modeling provides the tools to change the design without those time intensive extra steps. This is especially true of components produced using 3D printing, which is already dependent on Mesh Geometry.
In cases where a reverse engineering component needs to be used as the context for new designs, the workflow also gets much simpler. Engineers simply read in the point cloud and scan using Parametric and Direct Modeling capabilities as needed. The scanned component acts as a reference.
An important point in all these scenarios is the activities that this new breed of CAD applications lets engineers avoid: exchanging design data. Because all of these capabilities exist in a single environment, there is no need to move 3D data, scanned or otherwise, between different software applications. All of the work can be done in a single environment. Engineers need not waste time fixing geometry. They can focus on design instead.
Chad Jackson is an analyst