What is Reverse Engineering?


The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer models is known as reverse engineering.


Reverse engineering can be viewed as the process of analyzing a system to:


     1. Identify the many components and their interrelationships

     2. Create representations of the components in another form or a higher level of

          abstraction

     3. Create the physical representation of those components


Reverse engineering is often ignored by many restoration Companies who's primary objectives

are to replicate a visual apperence whithout fully understanding the application of the

components and their interrelationships.


In some situations, designers develop their ideas by using clay, plaster, wood, or foam rubber,

but a CAD model is needed to enable the manufacturing of the part. As products become more

organic in shape, designing in CAD may be challenging or impossible. There is no guarantee

that the CAD model will be acceptably close to the sculpted model. Reverse engineering

provides a solution to this problem because the physical model is the source of information

for the CAD model. This is also referred to as the part-to-CAD process.


Following are reasons for reverse engineering a part or product:


     1. The original manufacturer of a product no longer produces a product

     2. There is inadequate documentation of the original design

     3. The original manufacturer no longer exists, but a customer needs the product

     4. The original design documentation has been lost or never existed

     5. Some bad features of a product need to be designed out. For example, excessive wear might indicate where a product should be improved

     6. To strengthen the good features of a product based on long-term usage of the product

     7. To analyze the good and bad features of competitors' product

     8. To explore new avenues to improve product performance and features

     9. To gain competitive benchmarking methods to understand competitor's products and develop better products

     10. The original CAD model is not sufficient to support modifications or current manufacturing methods

     11. The original supplier is unable or unwilling to provide additional parts

     12. The original equipment manufacturers are either unwilling or unable to supply replacement parts, or demand inflated costs for sole-source

           parts

     13. To update obsolete materials or antiquated manufacturing processes with more current, less-expensive technologies


Reverse engineering enables the duplication of an existing part by capturing the component's physical dimensions, features, and material properties.  It is typically cost effective only if the items to be reverse engineered reflect a high investment or will be reproduced in large quantities. Reverse engineering of a part may be attempted even if it is not cost effective, if the part is absolutely required and is crucial to a system.


Reverse engineering of mechanical parts involves acquiring three-dimensional position data in the point cloud using laser scanners or computed tomography (CT). Representing geometry of the part in terms of surface points is the first step in creating parametric surface patches. A good polymesh is created from the point cloud using reverse engineering software. The cleaned-up polymesh, NURBS (Non-uniform rational B-spline) curves, or NURBS surfaces are exported to CAD packages for further refinement, analysis, and generation of cutter tool paths for CAM. Finally, the CAM produces the physical part.


It can be said that reverse engineering begins with the original vehicle and works through the design of such in the opposite direction to replicate the components of the original vehicle. In doing so, we uncover as much information as possible about the design ideas and proccesses that were used.