What is Reverse Engineering?
In Mechanical Engineering, the term Reverse Engineering (often abbreviated to RE) is used to summarise the process of reconstructing an already existing object. When designing an object from scratch, an engineer will draw up a design specification and produce drawings from which the item is constructed.
Conversely, with Reverse Engineering, the design engineer starts with the final product and works through the design process in the opposite direction to arrive at the product design specification. During the process, vital information about the design concept and manufacturing methods is discovered.
The usual starting point of the process of Reverse Engineering is by gaining dimensional information of the model, whether it is a mechanical component, a consumer product or an ancient artefact. This is done with the use of a 3D scanner, such as Physical Digital's highly accurate, GOM ATOS systems.
Why is Reverse Engineering used?
Reverse Engineering enables the duplication of an existing part by capturing the component's physical dimensions, features, and material properties.
There are a wide range of reasons for reverse engineering an object, including:
- Legacy Components – For many components that were designed and manufactured years ago, there are no existing 2D drawings or 3D CAD data from which to reproduce the object. Here, Reverse Engineering is a vital means to gain the information to recreate the product.
- Original Equipment Manufacturer (OEM) issues – If the OEM is no longer trading or has lost design measurements then Reverse Engineering will supply the vital product information for manufacturing.
- Design Development, Part Testing & Analysis – Through Reverse Engineering, a 3D product can be quickly captured in digital form and remodelled or analysed in order to achieve improved design iterations.
- Competitor Analysis – Any organisation can analyse competitor products through Reverse Engineering.
- Bespoke and Ancient objects – Where there is no information about the dimensions of an object except for the physical item itself, the quickest and most reliable way to reproduce it will be by Reverse Engineering. Where a product is organic in shape (not a standard geometry such as cuboid or cylindrical), designing in CAD may be challenging as it can be difficult to ensure that the CAD model will be acceptably close to the sculpted model. Reverse Engineering avoids this problem as the physical model is the source of the information for the CAD model.
- Modern manufacturing methods such as Additive Manufacturing rely on Reverse Engineering.
Physical Digital® reverse engineered the oldest Battle of Britain MkIIa Spitfire still flying today, providing a digital model of this priceless historic aircraft
- Digital Archiving – Museum pieces and historic artefacts can be captured through 3D scanning, then Reverse Engineered and the resulting CAD data can be held in case of any future damage to the object or any need to reproduce parts of the item.
Time and cost-effective way to produce models and products
The process of Reverse Engineering is particularly cost effective if the items to be reverse engineered represent a significant financial investment or will be reproduced in large quantities. Another advantage presented by Reverse Engineering is in compressing the product development cycle. In a highly competitive global market, manufacturers constantly strive to shorten lead-times to bring a new product to market. With Reverse Engineering, a 3D model can be quickly captured in digital form and remodelled if necessary or exported for a variety of manufacturing methods such as Additive Manufacturing, Vacuum Casting or CNC machining.
How to capture the data for Reverse Engineering
There are many ways of gathering valuable dimensional information about the product. Using an accurate measuring system is paramount. The accuracy of the data capture of the object will impact the quality and deviation of the Reverse Engineered model when compared to the original.
The old fashioned measuring devices such as slip gauge, calliper, tape measure, although quick and simple to use, have many limitations. The selection of a suitable measuring device has to reflect complexity of the shape. Advancement of technology in the last few decades has allowed us faster and more accurate measurement of components, irrespective of their shape and size.
Reverse engineering of mechanical parts involves acquiring three-dimensional positional data in the point cloud. Physical Digital uses the globally-recognised Geselleschaft für Optische Messtechnik (GOM) structured blue light 3D scanning systems, which offer accurate, traceable and repeatable measurement.
The GOM ATOS Triple Scan 3D scanning system offers highly accurate data capture
Representing the geometry of the part in terms of surface points is the first step in creating parametric or free-form surfaces. A highly accurate and dense polygon mesh is created from the point cloud using the native measurement software or a dedicated reverse engineering software.
The added benefit of a photogrammetry system provides even greater certainty of the data captured for larger objects, such as entire aircraft or boats. Photogrammetry is a separate metrology system designed to capture reference points using multiple digital images, using a verified DSLR camera. The GOM 3D scanning system can use these reference points to extend the potential scanning area, which means it is possible to capture larger items, which can then be reverse engineered.
Reverse Engineering Process
3D point cloud data - Optimised with curvature based thinning.
Scan Data - Polygonised 3D STL file.
CAD model - Accurate NURBS surfaces
Inspection Report - Highlighting any deviation CAD Vs Scan
Depending on the downstream application for the CAD model, different types of surfaces can be created, some optimised for redesign, remanufacture and other for analysis, evaluation and 3D printing.
Through the use of native inspection software, analysis of the RE model is performed and a decision can be made if the quality is of satisfactory level for the client’s specification. The image below represents a standard deviation analysis in GOM Inspect.
Why do we use Computer Aided Design (CAD)?
The use of CAD software is being heavily implemented for the creation of digital models to ease and speed up current manufacturing processes. Through the use of various CAD and Reverse Engineering software, we can create accurate data for manufacturing, analyse how it will perform in the real world and improve existing designs.
Computer-Aided Design (CAD)
CAD is the use of computer programs to create two- or three-dimensional (2D or 3D) graphical representations of physical objects. CAD software may be specialised for particular applications. CAD is widely used for computer animation and special effects in movies, advertising, and other applications where the graphic design itself is the finished product. CAD is also used to design physical products in a wide range of industries, where the software performs calculations for determining an optimum shape and size for a variety of product and industrial design applications.
In product and industrial design, CAD is used mainly for the creation of detailed 3D solid or surface models, or 2D vector-based drawings of physical components. However, CAD is also used throughout the engineering process from conceptual design and layout of products, through strength and dynamic analysis of assemblies, to the definition of manufacturing methods. This allows an engineer to both interactively and automatically analyse design variants, to find the optimal design for manufacturing while minimizing the use of physical prototypes.
Benefits of CAD
The benefits of CAD include lower product development costs, increased productivity, improved product quality and faster time-to-market.
The clear visualisation of the final product, sub-assemblies and constituent parts in a CAD system speeds the design process.
CAD software offers greater accuracy, so errors are reduced.
A CAD system provides easier, more robust documentation of the design, including geometries and dimensions, bills of materials, etc.
CAD software offers easy re-use of design data and best practices.
Physical Digital has expertise in various industries which will benefit our clients. We can support and manage your projects from start to finish. Contact us on 01483 750200 or email firstname.lastname@example.org to discuss your specific requirements.