Reverse Engineering Fundamentals: Process, Steps, and CAD Model Generation

Forward Engineering Defined

Forward engineering is the traditional process of moving from high-level abstractions and logical designs to the physical implementation of a system.

Understanding Reverse Engineering

Reverse engineering (RE) is the process of duplicating an existing part, sub-assembly, or product without original drawings, documentation, or a computer model.

It is also defined as the process of obtaining a geometric Computer-Aided Design (CAD) model from 3-D points acquired by scanning or digitizing existing parts.

Alternative Name for Reverse Engineering

The process is often referred to as the Physical-to-Digital process.

Key Purposes of Reverse Engineering (RE)

Reverse engineering serves several critical functions, including:

• The user needs a product made by the original manufacturer, but the manufacturer no longer exists.
• The original manufacturer no longer produces the product.
• Original product design documentation has been lost.
• Inspection and quality control: Comparing a fabricated part to its CAD description.
• Analyzing the good and bad features of competitors' products.
• Improving product performance and features by exploring new avenues.
• Creating 3-D data from a model or sculpture for animation in games and movies.
• Documentation and reproduction of crime scenes.

Fundamental Steps in Reverse Engineering

The base steps involved in the reverse engineering workflow are:

1. Scanning
2. Point processing
3. Application-specific geometric model development

The Scanning Process in Detail

Scanning involves several crucial activities:

• Selecting the correct scanning technique.
• Preparing the part to be scanned.
• Performing the actual scan to capture information describing all geometric features of the part.

Types of Scanners Used in RE

Scanners are generally categorized into two main types:

• Contact Scanners
• Non-Contact Scanners

Sensors in Non-Contact Scanning Systems

Non-contact scanners use advanced technology, typically employing lasers, optics, and charge-coupled device (CCD) sensors to capture point data.

Challenges with Non-Contact Scanners

A major challenge is that some non-contact systems have problems generating data describing surfaces that are parallel to the axis of the laser.

The Ultimate Goal: Generating CAD Models

The generation of Computer-Aided Design (CAD) models from the collected point data is often the most complex activity within the Reverse Engineering process.