COURSE ON

COMPUTER AIDED

REVERSE ENGINEERING

RAPID PROTOTYPING

INTRODUCTION

Engineering is the process of designing, manufacturing, assembling, and maintaining products and systems. 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/product without any technical details, such as drawings, bills-of-material, or without engineering data.

The process of duplicating an existing part, subassembly, or product, without drawings, documentation, or a computer model is known as reverse engineering. Reverse engineering is also defined as the process of obtaining a geometric CAD model from 3-D points acquired by scanning/ digitizing existing parts/products.

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 shortened product development time. By using reverse engineering, a three-dimensional physical product or clay mock-up can be quickly captured in the digital form, remodeled, and exported for rapid prototyping/tooling or rapid manufacturing using multi-axis CNC machining techniques.

Reverse Engineering –The Generic Process

The generic reverse engineering process is a three-phase process depicted in figure below. The three phases are scanning, point processing, and application specific geometric model development.

Figure 1: Reverse engineering based design methodology.

Why use Reverse Engineering?

Following are some of the reasons for using reverse engineering:

The original manufacturer no longer exists, but a customer needs the product, e.g., aircraft spares required typically after an aircraft has been in service for several years.
The original manufacturer of a product no longer produces the product, e.g., the original product has become obsolete.
The original product design documentation has been lost or never existed.
Creating data to refurbish or manufacture a part for which there are no CAD data, or for which the data have become obsolete or lost.
Inspection and/or Quality Control–Comparing a fabricated part to its CAD description or to a standard item.
Some bad features of a product need to be eliminated e.g., excessive wear might indicate where a product should be improved.
Analyzing the good and bad features of competitors’ products.
Exploring new avenues to improve product performance and features.
Creating 3-D data from a model or sculpture for animation in games and movies.
Creating 3-D data from an individual, model or sculpture to create, scale, or reproduce artwork.

COURSE OBJECTIVES

The course is designed for Engineers having an intermediate CAD knowledge, who are extensively involved in product design and development. The course will develop a clear understanding of complete reverse engineering methodology and techniques involved in it with an extensive focus on rapid prototyping techniques.

At the completion of the course the participants will have an in depth knowledge of

The reverse engineering methodology and techniques.
Reverse engineering hardware for contact, non-contact and destructive scanning like coordinate measuring machines, active 3-D stereo vision techniques, sheet light range imaging, X-ray tomography.
Reverse engineering software’s classification with pros and cons of available solutions.
Selection criteria’s for reverse engineering techniques.
Data points post processing, sampling techniques.
Curve and surface creation using NURBS based surfaces.
CAD model manipulation for application oriented model generation.
Rapid prototyping, Rapid tooling and Rapid manufacturing.
Available RP techniques, their integration with reverse engineering and data processing for rapid prototyping.
Usage of Rhino3D Nurbs based RE software package for completion of a detailed design project.

COURSE CONTENTS

Text Box: Module-1: Methodology and techniques for R.E.
· Reverse engineering, its need and its generic methodologies.
· Data Acquisition and Scanning techniques.
· Contact, Non-contact and Destructive method based RE hardware’s.
· Capability based R.E hardware comparison.
· Selection criterion’s for Reverse engineering system. The course will be comprised of 03 three modules with major contents elaborated below.

Text Box: Module-2: Point data processing.
· Data point handling and point cloud data formats.
· Scanning system data density and integrity comparisons.
· Modeling cloud data in CAD.
· CAD based and mathematical data sampling techniques.
· Curve and surface creation using NURBS based application packages.

DESIGN PROJECT

The course will also include an extensive design project requiring practice and implementation of all major techniques taught in the course. The project will require designing of a facial prosthesis from point cloud data of a human face and will involve extensive usage of surface modelling techniques and will help promote the understanding of the overall reverse engineering based design methodology.

The NURBS based CAD modelling package Rhinoceros 4.0 will be used for the project.

Multiple assignments will also be given to familiarize students with the package and eventually student will be required to discover the features of the software and manipulate given point cloud data using techniques elaborated in lecturers into a realistic nasal prosthesis model as shown in figure below.

Eligibility

This course is intended for product designers, drafters, and industrial / conceptual designers. People in other design related roles will also benefit from taking this course.

Course Duration

The minimum suggested course duration is 42 hours which includes in lab lecturers and practice on software.

Course Fee = Rs: 15000 / Participant