Reverse Engineering

Introduction

(Reverse engineering was often used during the Second World War and the Cold War. It is often used by military in order to copy other nation’s technology, devices or information, or parts of which, have been obtained by regular troops in the fields or by intelligence operations)

Engineering is the profession involved in forecasting, designing, manufacturing, constructing, and maintaining of products, systems, and structures. At a higher level, there are two types of engineering: forward engineering and reverse engineering

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

In some situations, there may be a physical part without any products technical details, such as drawings, bills-of-material, or without engineering data, such as thermal and electrical properties. The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer model is known as Reverse engineering. ←

Reverse engineering (RE) is the process of taking something (a device, an electrical component, a software program, etc.) apart and analyzing its workings in detail, usually with the intention to construct a new device or program that does the same thing without actually copying anything from the original.

Reverse engineering (RE) : A systematic methodology  for analyzing  the design of an existing device or system, either as an approach to study the design or as a prerequisite for re-design.

To accomplish this task, the engineer needs an understanding of the functionality of the original part and the skills to replicate its model and characteristics in details. In the fields of mechanical engineering and industrial manufacturing, reverse engineering refers to the method of creating engineering design and documentation data from existing parts and their assemblies.

The new analytical technologies, such as three-dimensional (3D) laser scanning and high-resolution microscopy, have made reverse engineering easier, but there is still much more to be learned. Several professional organizations have provided the definitions of reverse engineering from their perspectives. It has been incorporates in appropriate mechanical design and manufacturing engineering standards and multiple realistic product constraints with broad knowledge in multiple disciplines such as:


• Applying knowledge of mathematics, engineering, and science in data analysis and interpretation. 
• Using process, techniques, instruments, and tools in reverse engineering applications 
• Conducting appropriate experiments and tests to obtain the necessary data in reverse engineering. 
• Identifying, formulating, and solving issues related to reverse engineering.
• Understanding legal and ethical responsibilities pertinent to reverse engineering. 
• Assessing and evaluating documents and fostering attainment of objectives of a reverse engineering project. 

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

1. Identify the system's components and their interrelationships
2. Create representations of the system in another form or a higher level of abstraction
3. Create the physical representation of that system

Reverse engineering is very common in such diverse fields as software engineering, entertainment, automotive, consumer products, microchips, chemicals, electronics, and mechanical designs. For example, when a new machine comes to market, competing manufacturers may buy one machine and disassemble it to learn how it was built and how it works. A chemical company may use reverse engineering to defeat a patent on a competitor's manufacturing process. In civil engineering, bridge and building designs are copied from past successes so there will be less chance of catastrophic failure. In software engineering, good source code is often a variation of other good source code.

In some situations, designers give a shape to 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.

Another reason for reverse engineering is to compress product development times. In the intensely competitive global market, manufacturers are constantly seeking new ways to shorten lead-times to market a new product. Rapid product development (RPD) refers to recently developed technologies and techniques that assist manufacturers and designers in meeting the demands of reduced product development time. For example, injection-moulding companies must drastically reduce the tool and die development times. By using reverse engineering, a three-dimensional product or model can be quickly captured in digital form, re-modelled, and exported for rapid prototyping/tooling or rapid manufacturing.

Reasons for reverse engineering:

1. The original manufacturer no longer exists, but a customer needs the product
2. There is inadequate documentation of the original design
3. The original design documentation has been lost or never existed
4. Some bad features of a product need to be designed out. For example, excessive wear might indicate where a product should be improved
5. To strengthen the good features of a product based on long-term usage of the product
6. To analyse the good and bad features of competitors' product
7. To explore new avenues to improve product performance and features
8. To gain competitive benchmarking methods to understand competitor's products and develop better products
9. The original CAD model is not sufficient to support modifications or current manufacturing methods
10. The original supplier is unable or unwilling to provide additional parts
11. The original equipment manufacturers are either unwilling or unable to supply replacement parts, or demand inflated costs for sole-source parts
12. To update obsolete materials or antiquated manufacturing processes with more current, less-expensive technologies
13. Learning about a competitor’s latest research by capturing data to secure as much information as possible to understand its capabilities.

Reverse engineering enables the duplication of an existing part by capturing the component's physical dimensions, features, and material properties. Before attempting reverse engineering, a well-planned life-cycle analysis and cost/benefit analysis should be conducted to justify the reverse engineering projects. Reverse engineering 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 mission-critical 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 product and works through the design process in the opposite direction to arrive at a product definition statement (PDS). In doing so, it uncovers as much information as possible about the design ideas that were used to produce a particular product. Reverse engineering was originally a crucial tool to gain military advantage and latterly for commercial analysis and gain.

Steps in Reverse Engineering Process:

Identify The Purpose: When you are ready to reverse engineer a product, begin by recording your purpose in your engineer’s notebook. What do you want to learn about the product? Think about questions to ask, area of research, people to contact, and tests to be completed. It’s important that you keep accurate and detailed documentation throughout the entire reverse engineering process. Engineer’s notebook will provide evidence of your process, thoughts, and findings. Whenever possible, you should add supporting documentation, such as annotated sketches. Ultimately, notebook will support your findings and may serves as evidence to support legal proceedings or a patent application.

•           What is the purpose of this product?

•           How does it work?

•           What market was it designed to appeal to?

•           List some of the design objectives for the product.

            •           List some of the constraints that may have influenced the design

In disassemble process components will be disassemble to examine the theories and predictions, this steps dealing with the following questions,
How does it work?
How is it made?
How many parts?
How many moving parts?

Analyse The Elements:

Data capture involved with the scanning strategy- selecting the correct scanning technique, preparing the part to be scanned, and performing the actual scanning to capture information that describes all geometric features of the parts such as, steps, slots, pockets and holes. Three-dimensional scanners are employed to scan the part geometry, producing clouds of points, which defines the surface geometry. These scanning devices are available as dedicated tools or as add-ons to the existing computer numerically controlled machine tools. There are two distinct types of scanners, contact and non-contact.

Analysis is the most crucial part of the reverse engineering process. During the analysis step, engineers attempt to answer all of the questions originally posted. There are four main categories of product analysis,

-Functional

-Structural

-Material

-Manufacturing

Analysis requires detailed research of each category. Research results are recorded in engineer’s notebook along with sketches and digital photos to provide clarity for detailed information. During analysis, some products may require partial reassembly to observe the interaction of functional components.

• Carefully reassemble the product.
• Operate the device and record observations about its performance in terms of functionality (operational and ergonomic) and projected durability

Material Analysis: The choice of material greatly affects a parts performance, and the material properties must be correctly matched to the parts application. Analysing materials requires understanding basic material properties (mechanical, electrical, thermal, chemical, optical, acoustical), because materials are also identified by scientific properties.

After the analysis, Report preparation process tabulate following things

• Inferred design goals
• Inferred constraints
• Design (functionality, form (geometry), and materials)
• Schematic diagrams
• Lists (materials, components, critical components, flaws, successes, etc.)
• Identify any refinements that might enhance the product’s usefulness.
• Upgrades and changes