Reverse engineering for mechanical

IN THIS BRIEFLY EXPLAIN ABOUT REVERSE ENGINEERING

1. REVERSE ENGINEERING BY p.vishnu

2. contents Introduction Compassion between forward engineering and reverse engineering Importance Methodology Digitizing Discretization method Manipulation of data Generation of functional part Advantages and Applications of reverse engineering

3. Introduction Engineering is the profession involved in designing, manufacturing, and maintaining products, systems, and structures. The whole engineering process can be broadly classified in two groups; 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. Figure 37.1 Forward Engineering The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer model is known as reverse engineering. . Figure 37.2 Reverse Engineering

4. engineering can be mainly viewed as the process of analyzing a system to identify its components and their interrelationships, to create representations of it in another form or a higher level of abstraction. An important reason for application of reverse engineering is reduction of product development times. In the intensely competitive global market, manufacturers are constantly seeking new ways to shorten lead-times to market a new product. For example, injection-molding 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-modeled, and exported for rapid prototyping/tooling or rapid manufacturing.

5. 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.

6. Compassion between forward engineering and reverse engineering

7. 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.

8. Methodology Digitization of the object/ Data Capturing (using CMM, scanners etc.) Processing of measured data Creation of CAD model Prototype

9. Example

10. 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.

11. Discretization method Contact method Non Contact method • Requires contact between the component surface & a measuring tool. • Uses Coordinate Measuring Machine (CMM), electromagnetic digitizer or sonic digitizers to get desired coordinates. • Uses light as the main tool • Uses white light or laser scanners to scan 3D objects to generate CAD design.

12. Manipulation of data Basically, after completion of this a CAD model of product is obtained. Used to fit a geometry to the large number of points obtained from digitizing. The surface can be mathematically defined as algebraic or parametric surface. Surface fitting techniques can be of two types: interpolation and approximation techniques.

13. Surface fitting techniques Interpolation technique Surface to be fitted passes through all the data points . Used when the data points are accurately measured without any errors. Approximation technique Surface represents a generalized or best fit to the data points. Used when large number of data points are to be fitted.

14. Generation of functional part The geometric model obtained, can be used as the basis for variety of operations. Operations such as automated process planning, automated manufacturing, automated dimensional inspection and automated tolerance analysis.

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

16. Applications Manufacturing Field: To create a 3D virtual model of an existing physical part for use in 3D CAD, CAM, CAE or other software and to analyze the working of a product . Medical Field: Imaging, modeling and replication (as a physical model) of a patient's bone structure Software engineering: To detect and neutralize viruses and malware.