Accurate CAD Modeling for Reverse Engineering; Are Design Engineers Aware Of All The Essentials?
How many times has it occurred that the products you’ve manufactured or designed did not match the exact design intent (for whatsoever reason) at the first go?
We know it occurs to almost every manufacturer and designer several times. Mistakes and deviations are bound to occur more often than one can imagine. Once manufactured, these components outlive its paper drawings. When it is time for their replacement, the physical part does not match with the original drawings due to constant wear and tear and improper maintenance. This initiates a need for scanning the physical component, 3D modeling from the scanned data and final dimension check of the model for model accuracy.
What is Reverse Engineering?
Today, for design engineers, reverse engineering is not any far from its full-fledged industrial adaptability. It involves two basic processes of scanning the component and generating a 3D CAD. The old techniques of measuring parts adequately and capturing dimensional data using calipers fails in determining curvature and internal details of the component accurately.
Use of laser scanning and CMM techniques has been successful in overcoming these drawbacks. High resolution laser scanners allow scanning the 3-dimensional topography of the component with much clarity and generate a point clouds. Yet, the scanned data alone is not sufficient in extracting relevant information accurately and needs to be converted to editable vector drawings in the form of 3D CAD models. These CAD models are generated using any CAD software, few of which are SOLIDWORKS, Creo or Inventor. These editable CAD models can be easily stored and analyzed for Product Lifecycle Management (PLM). Once the final model is generated, it is essentially compared against the scanned data to verify for deviation analysis and quality control.
Deviation Analysis for Part Accuracy
It becomes utmost important to check that the geometry of CAD models complies with the original component. Design engineers use deviation analysis or Computer Aided Inspection – CAI for final assessment of CAD model with the actual component, using the original input of scanned data.
Since the 3D CAD models are generated on the basis of information obtained from scanned data, models are compared against the point clouds for verification. Aligning the point clouds of scanned image with the model determines the actual deviation of model. It compares each and every element, dimension, part, and validates the model as per actual physical existence. Through computer aided technique, deviation from the original design can be traced accurately and required changes can be done. Deviation analysis empowers design engineers for generation of rapid and accurate results, provided that the scanning process is done accurately with a high resolution scanner.
The accuracy shows conformation and scale of relevance of CAD model with the scanned data. With manual methods, achieving this sort of accuracy is almost impossible.
The accurate models so created with verified minimum deviation from the scanned point can be employed for manufacturing process analysis and information inclusion. CNC machining for CAM and PLM can be easily determined and studied with the 3D CAD models generated through reverse engineering.