Reverse engineering is a systematic process of analyzing existing systems or products to understand their design or redesign them. It involves creating CAD models from physical objects using techniques like 3D laser scanning or CT scanning. Reverse engineering has applications in new product design, redesign of existing products, custom product design, and modifying physical models. It is an efficient approach to significantly reduce product development time by optimizing available resources and meeting customer requirements. The reverse engineering process includes data capturing, processing measured data, CAD modeling, and creating prototypes. Common digitizing techniques are contact methods using CMM and non-contact methods like laser scanning and CT scanning.

1. REVERSE ENGINEERING
Submitted to
Dr. Komal G Dave
Associate Professor
L D College Of Engineering-
Ahmedabad

2. WHAT IS REVERSE ENGINEERING?
A systematic methodology for analyzing the design of
an existing device or system, either as an approach to
study the design or for re-design.
It involves creating a CAD model from a physical model,
it is the inverse of the normal process of producing a
part from a CAD model.

3. APPLICATION OF REVERSE ENGINEERING
1. New product design
2. Existing product redesign
3. Custom product design
4. Physical model-based shape modification

4. IMPORTANCE OF REVERSE ENGINEERING
1. We cannot start from the very beginning to develop a
new product every time.
2. We need to optimize the resources available in our
hands and reduce the production time keeping in view
the customers’ requirements.
For such cases, RE is an efficient approach to significantly
reduce the product development cycle.

5. REVERSE ENGINEERING PROCESS
1. Digitization of the
object/Data Capturing (using
CMM, scanners etc.)
2. Processing of measured data
3. CAD modeling or model
updating
4. Prototype
(a) wooden pattern (b) cloud of points
(c) 3D CAD model Fabricated RP Model
CAD model generation using laser scanner:

6. DIGITIZING TECHNIQUES
The four basic construction
units of a digitizing setup.
1. Mechanical contact ( CMM )
2. Non-contact measuring
techniques
Optical triangulation method
1. Single beam configuration
2. parallel-collimated multi-beams
configuration
3. single slit beam configuration
4. multi-slit beams configuration
5. intersectional multi-slit beams configuration
Moire method
Photogrammetry
Imaging radar
Focus method
3. CT Scanning Method
1st
CT Scanning Method

7. 1. Mechanical contact ( CMM )
In this method, there is physical contact between the measuring instrument and the surface being measured to
record as many dimensions as possible.
(a) Hand Tools :
• Micrometers, Vernier calipers and Gauges
• These are used to capture the critical dimensions needed
to generate a part drawing.
(b) Co-ordinate measuring machine ( CMM ) :
A CMM consists of a contact probe that can be positioned
in 3-D space relative to the surfaces of workpart and x, y & z coordinates
of the probe are accurately and precisely recorded to obtain
dimensional data concerning the part geometry.

8. How Do Coordinate Measuring Machines Work?
• After placing a work piece on the machine
table, a probe is used to measure different
points on it by mapping the x, y, z coordinates.
• The probe operates either manually via an
operator or automatically via a control system.
• These points are then uploaded to a computer
interface where they can be analyzed using
modeling software (e.g. CAD) and regression
algorithms for further development.

9. Types of CMM
Horizontal arm type CMM
Articulated arm type CMM
Cantilever type CMM

10. 2. Non-contact measuring techniques
Data acquisition is done without physically touching the part.
• It uses structured lighting and reflection from the object to get the 3-D image of the object.
It consists of following techniques :-
(1) 3-D Laser Scanning
( Triangulation Technique : triangulation method , Moire method , Photogrammetry , Focus method )
( Time of flight Technique : Imaging radar )
(2) Industrial CT Scanning
Reflection of
LASER
Light from object
Capture of light
by CCD sensor
Cloud of points
( COP )
generation
3-D Image
formation
Working Principle of 3-D Laser Scanning

11. Triangulation Technique:
A Point Cloud is a set of vertices in a 3-D coordinate system.
 Point clouds are most often created by 3D scanners.
 The point cloud represents the set of points that the device
has measured.
 Many no. of points detected by scanner give 3-D image
of the object.
 This point clouded 3-D image is converted into CAD models by Reverse engineering software.

12. MILROY, M. J., ET AL. "REVERSE ENGINEERING EMPLOYING A 3D LASER SCANNER: A
CASE STUDY." THE INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING
TECHNOLOGY 12.2 (1996): 111-121.
In this paper author works on reverse engineering process, through LaserCAM, involves scanning the part,
recognising and reconstructing the primitive and free-form surface regions, and creating a suitable CAD

13. Time of flight Technique:
It finds the distance of a surface by timing the
round-trip time of a pulse of light.
velocity of light = C
Round-trip time (t) = 2 * time required to travel
distance between scanner & surface
distance (d) = c.t/2

14. Industrial CT (Computed Tomography) Scanning
Tomography refers to imaging by sections or
sectioning, through the use of any kind of
penetrating wave. A device used in
tomography is called a Tomograph, while the
image produced is a Tomogram.
• It uses X-ray equipment to produce 3-D
representations of components both
externally and internally.
Types of scanners :
(i) Fan/Line beam scanners
(ii) Cone beam scanners

15. Collimated beam
of X-rays
Fan/Line beam scanners
Cone beam scanners

16. ADVANTAGES OF USING CT SCANNING OVER
OTHER TECHNIQUES SUCH AS CMM OR 3D
LASER SCANNERS
Design requirements for both internal and external components are validated
quickly and accurately
• Product quality is improved.
• Internal complex features can be precisely measured without destructive testing
• Parts are scanned in a free-state environment without applying stresses which
could damage delicate parts.
• For the first time, rapid prototyping of the internal components can be
completed without the daunting task of creating the CAD file from scratch.

17. PROCESSING OF MEASURED DATA
registration
Registration transforms the measured results obtained from different
setups into a single coordinate system.
Data cleaning Data cleaning wipes out all points not on the part surface.
Data reduction reduces the number of points if they are too many to
handle
Data reduction
Segmentation is combined data set into individual regions, each
representing a single geometric feature that can be mathematically
represented by a simple surface.
Segmentation
2nd

18. CHEN, LIANG-CHIA, AND GRIER CI LIN. "REVERSE
ENGINEERING IN THE DESIGN OF TURBINE BLADES–A CASE
STUDY IN APPLYING THE MAMDP." ROBOTICS AND COMPUTER-
INTEGRATED MANUFACTURING16.2-3 (2000): 161-167.

19. CAD MODELING OR MODEL UPDATING
CAD Modeling :
The segmented data are further transformed into individual surfaces. Several mathematical
schemes for representing geometrical shapes are available. One can also use interpolation or
fitting techniques for identifying the parameters of the geometrical shape. After fitting
individual surfaces to measured points, the surfaces must be further processed to form the
complete CAD model.
CAD Model updating :
When a product design is directly modified on the shop floor through adjustments to the
physical prototypes, the CAD model must be further updated according to the changes made
to the physical part.
3rd

20. AREAS OF APPLICATION
Manufacturing Engineering :
To create a 3D virtual model of an existing custom
physical part for use in 3D CAD, CAM, CAE or
other software
• To make a digital 3D record of own products
• To assess competitors‘
products
• To analyze the
working of a product
Bagci, Eyup. "Reverse engineering applications
for recovery of broken or worn parts and re-
manufacturing: Three case studies." Advances
in Engineering Software 40.6 (2009): 407-418.

21. AREAS OF APPLICATION
Film-Entertainment Industry :
Animated objects are imparted motion using the
reverse engineered human skeletons
Chemical Engineering :
To determine chemical composition
To substitute or improve recipes to stimulate or improve the products performance

22. AREAS OF APPLICATION
Medical Field :
1. Applications in orthopedic, dental & reconstructive surgery
2. Imaging, modeling and replication (as a physical model) of a patient's bone structure
3. Models can be viewed & physically handled before surgery, benefiting in evaluation of
the procedure & implant fit in difficult cases
4. Less risk to the patient and reduced cost through saving in theatre time
Software Engineering :
1. To extract design & implementation information (Byrne, Eric J-1991)
2. To detect and neutralize viruses and malware

23. REFERENCES
1. Venuvinod, Patri K., and Weiyin Ma. Rapid prototyping: laser-based and other technologies.
Springer Science & Business Media, 2013.
2. Kamrani, Ali K., and Emad Abouel Nasr, eds. Rapid prototyping: theory and practice. Vol. 6.
Springer Science & Business Media, 2006.
3. Byrne, Eric J. "Software reverse engineering: a case study." Software: Practice and
Experience 21.12 (1991): 1349-1364.
4. Milroy, M. J., et al. "Reverse engineering employing a 3D laser scanner: a case study." The
International Journal of Advanced Manufacturing Technology 12.2 (1996): 111-121.
5. Chen, Liang-Chia, and Grier CI Lin. "Reverse engineering in the design of turbine blades–a case
study in applying the MAMDP." Robotics and Computer-Integrated Manufacturing16.2-3 (2000):
161-167.
6. Bagci, Eyup. "Reverse engineering applications for recovery of broken or worn parts and re-
manufacturing: Three case studies." Advances in Engineering Software 40.6 (2009): 407-418.

24. THANK YOU!
Do you have any questions?