Reverse engineering is the process of analyzing an existing product to understand its design and recreate the product. It involves digitizing a physical part to create a 3D CAD model without original drawings. Reverse engineering was used to recreate the design of a crankshaft, which involved measuring dimensions, tracing profiles, scanning with a CMM, parameterizing the profile, and creating a 3D model in ProE. The process allowed for recreating technical drawings and models without original documentation.

1. DR. D. Y. PATIL INSTITUTE OF ENGINEERING
MGMT.
& RESEARCH
Department of mechanical engineering
Presented By:-
Falesh Sharma
Presentation
on
Reverse Engineering

2. Contents
 What is Reverse Engineering (RE)?
 Why do we need Reverse Engineering?
 Scope and Tasks of Reverse Engineering
 Different Approaches
 RE tools
 Conclusions

3. What is Reverse Engineering ?
 Reverse Engineering is a process of redesigning an
existing product to improve and broaden its functions,
add quality and to increase its useful life.
 The main aim of reverse engineering is to reduce
manufacturing costs of the new product, making it
competitive in market.
 The duplication is done without the aid of drawings,
documentation or computer model.

4. Why reverse engineering?
 The original producer no longer produces the
product.
 There is inadequate documentation of product.
 Some bad features of the product needs to be
redesigned.
 To update obsolete materials or antiquated

5. Methodology

6. Digitizing
 Collecting data from physical part.
 Used when drawing of object is not available.
 Aim is to generate a 3D mapping of the product in
the form of CAD file.
 This requires acquisition of surface data, which is
large number of points on the product surface.
 For this two types of processes are used: contact
and non contact method

7. Why do we need RE ?
 Recovery of lost information
• providing proper system documentation
 Assisting with maintenance
• identification of side effects and anomalies
 Migration to another hw/sw platform
 Facilitating software reuse

8. Difficulties of Reverse
Engineering
 Gap between problem /solution domain
 Gap between concrete and abstract
 Gap between coherency/disintegration
 Gap between hierarchical/associational

9. Scope and Task of Reverse
Engineering
 Re-documentation and/or document generation
 Recovery of design approach and design details at any level of
abstraction
 Identifying reusable components and components that need
restructuring
 Recovering business rules
 Understanding high-level system description.

10. Reverse Engg. Of crank shaft
(Methodology)
 The old, which is currently not in use, crankshaft is
selected for reverse engineering, whose 3D model
and two dimensional drawing is to be created.
Primary inspection of model shows that there are two
main profiles on the crank shaft which are required to
trace out. Remaining other dimensions can be easily
measured using micrometer and Vernier caliper.
Following figure shows Photo of the crankshaft and
traced profiles of that crankshaft.

11. REVERSE ENGINEERING
 Measurement of Major dimensions:The major dimensions of
the part measured by steel rule, Vernier caliper and micrometer.
Rounding of dimension with acceptable tolerance is done
whenever it required.
 Tracing of profile: The profile is traced using trace paper and
graph paper. Origin is assumed. With respect to that X-Y co-
ordinates of points are determined.

12. REVERSE ENGINEERING
 Coordinate measuring machine scanning: The profile of part
is scanned on CMM to verify the traced profile. CMM data and
traced points shows similarity but CMM data when taken in ProE
it shows scale difference. Due to that traced profile is used for
making final drawing.
 Parameterization of Profile:To form parametric profile total 34
points are taken, following figure shows traced profile on graph
paper. Symmetry of profile is used. Radius of arc is measured
and rounded off with acceptable tolerance if required.

13. REVERSE ENGINEERING
 Creation of 3D model: Three dimensional model of
crankshaft is created using measured dimensions.
ProE software is used to create this model.
Parameterization of dimensions, modification, draft
angle, and static and dynamic analysis etc. can be
done on this part. By taking stl file output rapid
manufacturing of part can be done.

14. Conclusions
 Using reverse engineering methodology 2D
drawing and 3D model of crankshaft is
constructed using simple measuring devices e.g.
Vernier caliper, graph, micrometer drawing of
crankshaft is produced. CMM scanning and
tracing is carried out. Critical profiles can be
parameterized using these techniques.