Reverse engineering is the process of systematically evaluating a product to replicate or redesign it. It is an important step in product development that allows optimization of resources and reduction in development time and costs. The reverse engineering process involves digitizing an existing object through scanning or other methods, processing the captured data to create a CAD model, and then using that model to develop prototypes or redesign parts as needed. It has various applications in fields like manufacturing, software, chemicals, entertainment, and medicine. A case study described how reverse engineering and rapid prototyping were used together to redesign turbine blades by capturing high-quality surface data and iteratively digitizing to create accurate CAD models.

1. Reverse Engineering & Its
Application

2. Reverse Engineering
• Systematic evaluation of a product with the purpose of replication.
 Design of a new part
 Copy of an existing part
 Recovery of a damaged or broken part
• An important step in the product development cycle.

3. Importance
• We cannot start from the very beginning to develop a new product
every time.
• 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.
For example: Impeller Pump Design

4. Suppose there is a impellor pump which had an original pumping
capacity of 20000 cubic feet of water per minute; now, after a year of
use, the pump manufacturing company finds that it is pumping 19000
cubic feet per minute. They need to figure out what happened to that
extra 1 thousand cubic feet in performance. The pump manufacturer
scans the year-old impeller into the CAD system. Once those
measurements are captured, engineers can compare the
measurements taken from the actual impeller against the original, as-
designed part. This helps determine exactly how and where the part
has degraded. With that information in hand, engineers can redesign
the impeller to avoid future loss in pumping capability.

5. Advantages
• RE typically starts with measuring an
 Cost saving for developing
existing object, so that a solid model can new products.
be deduced in order to make use of the
advantages of CAD/CAM/CAE technologies.
 Lesser maintenance costs
• CAD models are used for manufacturing or
rapid prototyping applications.
 Quality improvement
• Hence we can work on a product without
having prior knowledge of the technology
 Competitive advantages
involved.

6. RE Process
I. Digitization of the object/
Data Capturing (using
CMM, scanners etc.)
II. Processing of measured
data
III. Creation of CAD model
IV. Prototype

7. Rapid Prototyping in combination with
RE
• A group of techniques to quickly fabricate a scale
model of a physical part or assembly using
3D CAD data
• Integration of reverse engineering and rapid
prototyping is being used for getting product to
the market quickly by resolving a long-standing
conflict between design and manufacturing

8. a b c
CAD model generation using laser scanner:
(a) wooden pattern, (b) cloud of points, and (c) 3D CAD model
Fabricated RP Model

9. Areas of Application
Design of a new component
Reproduction of an existing component
Improving quality & efficiency of existing parts

10. Manufacturing Engineering
• To create a 3D virtual model of an existing
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
• To identify potential patent infringement etc.

11. Software Engineering
• To extract design & implementation information
• To detect and neutralize viruses and malware
Chemical Engineering
• To determine chemical composition
• To substitute or improve recipes to stimulate or improve the
products performance

12. Film-Entertainment Industry
• Animated objects are imparted motion using the
reverse engineered human skeletons

13. Medical Field
• Applications in orthopedic, dental & reconstructive surgery
• Imaging, modeling and replication (as a physical model) of a
patient's bone structure
• Models can be viewed & physically handled before
surgery, benefiting in evaluation of the procedure & implant fit in
difficult cases
• Less risk to the patient and reduced cost through saving in theatre
time

14. Medical Field Applications
Hip Replacement

15. A Case Study
Adapted from “Reverse engineering in the
design of turbine blades-a case study in
applying the MAMDP” by Liang-Chia Chen, Grier
C.I. Lin

17. • The large amount of surface data generated from the fast
3D digitizers is not easily modeled by current CAD/CAM
systems. Inadequate data reduction methods are not only
time consuming, but lose surface characteristic points.
• Consequently, the reconstructed surfaces could lose their
true shape in the design cycle. The time required for
reprocessing in this case would be unacceptable to the
manufacturing industry and thereby be unusable for
further steps.

18. • The study describes how the developed
reverse engineering approach MAMDP was
successfully applied to design of turbine
blades and the existing problems encountered
in reverse engineering processes were
overcome.
• MAMDP stands for Modified Adaptive Model-
based Digitizing Process

20. A 3D initial triangular patch of a subdivided surface patch generated by IVSTP
The surface triangular patch of a The surface model of a subdivided surface
subdivided surface patch of the turbine patch of the turbine blade
(before surface trimming)

21. The surface model of the measured turbine blades.

22. Generation of initial surface triangular
patches of turbine blades
• A charge-coupled device (CCD) camera is used
to rapidly detect the object's position and
measure its surface boundary coordinates, to
establish exploration paths for further
automatic surface digitization of a touch
probe.

23. • Free-form surface subdivided into an adequate number of
individual surface patches
• 3D stereo detection method is applied to automatically
detect 3D surface boundaries
• Initial triangular patch by applying Triangulation process
• A 3D initial triangular surface patch can be rapidly
generated & used for probe exploration paths in the
following MAMDP

24. Automatic surface digitization &
surface modeling by using the MAMDP
• The surface model is used to calculate the
new exploration points at the approximate
midpoints between the vertices of the initial
triangular patch.
• CMM then automatically digitizes these
exploration targets

25. • Adaptive approach evaluates the digitizing accuracy by
calculating the deviations between the target points
and the digitized points
• New exploration targets will be generated at the
estimated midpoints between vertices of those
triangular patches where deviations are higher than
the user-specified tolerance
• This iterative digitizing loop will continue until all new
digitized deviations are within the specified tolerance

26. • Totally 786 surface characteristic points were automatically
digitized by a touch-triggered probe in CMM. The time
spent for this job was 45 min. The digitizing accuracy can be
controlled within 0.25 mm and the maximum fitted error in
the resulting surface model is reduced to 0.030 mm using a
least-squares fitting method.
• To generate a complete CAD surface model of turbine
blades, the individual surface models generated from the
MAMDP have to be merged, according to their geometric
relationship. (Using CAD/CAM package ANVIL5000)

27. Future Scope & Possibilities
With the advent of RE & RP, we can hope to see
commercial and domestic use of these technologies
to manufacture desired products at home and offices
which will be revolutionary in coming time.
Possibilities of use of this technology is only
restricted by boundaries of human thinking.

28. • 3D laser scanners as robot eye for scanning objects specially in
space missions.
• Scanning technology can be integrated with mobile
phones/cameras and can be used for 3D printing at domestic level.
• Tissue engineering applications where organs and body parts are
built using inkjet techniques. Layers of living cells are deposited
onto a gel medium or sugar matrix and slowly built up to form three
dimensional structures including vascular systems.
• Availability of 3D printers at every home as is now of the normal
printers.

29. Around the World…
• 'Wiki Weapon Project' Aims To Create A Gun Anyone Can
3D-Print At Home.
• The open source Fab@Home project has developed
printers for general use which can use anything squirtable
through a nozzle, from chocolate to silicon sealant and
chemical reactants.
• Some companies offer an on-line 3D printing service open
both to consumers and to industry.

30. RE of trans tunnel by Macomb College Students
Video

31. References
• Eyup Bagci, Reverse engineering applications for recovery of broken or worn parts
and re-manufacturing: Three case studies, Advances in Engineering Software 40
(2009) 407–418
• Yu Zhang, Research into the engineering application of reverse engineering
technology, Journal of Materials Processing Technology 139 (2003) 472–475
• Liang-Chia Chen, Grier C.I. Lin, Reverse engineering in the design of turbine
blades}a case study in applying the MAMDP, Robotics and Computer Integrated
Manufacturing 16 (2000) 161-167
• http://en.wikipedia.org/wiki/Reverse_engineering
• http://www.asme.org/kb/news---articles/articles/computational-methods---
modeling/the-rise-of-reverse-engineering
• R. Schenker, Novel combination of RE & RP in medicine, South African Journal of
Science, 95, August 1999
• 'Wiki Weapon Project' Aims To Create A Gun Anyone Can 3D-Print At Home-
http://www.forbes.com/sites/andygreenberg/2012/08/23/wiki-weapon-project-
aims-to-create-a-gun-anyone-can-3d-print-at-home/

32. Thank You!