Sep 14, 2016 -- Engineering professionals today rely entirely on the CAD world for design development. Right from concept development to design and manufacturing, CAD model remains a vital link that keeps product development process seamless. Thus, a CAD library consisting of all the parts and assemblies is a vital asset for companies, as these models provide the means to develop the actual physical product. And it is due to this reason that organizations are willing to store the design information, even for their legacy parts or products whose digital CAD model is not available.
Reverse engineering is primarily employed to develop 3D CAD models for such parts, and at times for producing the model for a complex shaped object.
3D scanning technique is usually employed for converting physical part to a 3D CAD model by capturing the geometry and generating CAD friendly surfaces, lines and solids.
Major Applications of Reverse Engineering
- Develop CAD model by capturing the part’s original design intent
- Design new parts that fit with other legacy part in an assembly
- Model performance surfaces
- Revise CAD models for tooling with changes in shop-floor
- Redesign a part or product consisting of manufacturing defects
- CAD model for animation and visualization requirements
- Comparative analysis between physical and virtual part
- Perform virtual tests using FEA and CFD
- Reconstruct damaged part and reproduce it with original design intent
While there are numerous 3D scanning technologies available, the scanners can be stationary or portable. The technology scans the object surface and generates geometrical information to develop the CAD geometry. These 3D scanners are widely used in scanning vehicles, aircrafts, monuments, ships, buildings, sculptures, consumer products and many other objects.
Working of 3D Scanners
A typical laser scanner passes a laser light over the object surface and the sensor mounted within the scanner records the surface data and saves 3D information to a model. On a single scan, all the regions of the objects are recorded in the form of numerous points, which are then refined to form the 3D model. The laser scanning process however is performed without actually making any contact with the physical object.
However, a contact based process called digitization is also one of the forms of laser scanning. In this method, a ball probe is used to scan specific points on the object surface and geometrical position is recorded. This method is mostly used in reverse engineering projects for industrial projects, where precision is important. The versatility of 3D scanning also allows it to be used for scanning large objects like vehicles and buildings.
However, there are certain limitations of 3D scanning as well:
- 3D scanning can be inefficient in bright lightings; as such outdoor scanning projects can only be conducted when lights are minimum
- The accuracy of 3D scans is more for matte surface finish as compared to reflective ones as they reflect white light. For reflective surfaces, sprays are used that dull the surface.
- Complex objects like large sculptures require both stationary as well as handled scanners to accurately scan the object.
3D Scanning for Part Inspection
Another application of 3D scanning is to inspect parts for various design aspects like meeting manufacturing tolerances. 3D scanning technique is often used for first article inspection, where there is a need for the manufactured part to meet accuracy and quality as mentioned in the drawings. The technology is also useful in scanning the finalized part, to generate final 3D models and drawings that can be considered as final blueprints for future requirements. Apart from this, 3D scanning is helpful to inspect components in aging products or systems, so that modifications or updates required in the systems can be determined.
Consider an example of our client’s steel strapping machine, which was meant to be reverse engineered to study the cause of early failure and accordingly develop a new design of the machine. With 3D scanning, the CAD model of the original steel strapping machine was developed, capturing geometric information of each and every component of the machine.
Original steel strapping machine to be reverse engineered
Finite element analysis performed on the component of the steel strapping machine
A finite element analysis was then performed, which revealed that two of the components were undergoing stress beyond their allowable limit, which resulted in early failure.
3D CAD model of the new steel strapping machine developed in SOLIDWORKS
The design was then modified, considering the results from the simulation and a new steel strapping machine with better ergonomics was developed.
3D scanning for reverse engineering brings opportunities in multitude for manufacturers and design engineers. If you are interested to reverse engineer your product, we at Hi-Tech can help you with our experience and expertise developed over the course of more than 10 years.