Scanning for Reverse Engineering
Summary: A motor and gear drive manufacturing company needed a 3 Dimensional CAD file for a set of gears. They wanted to reverse engineer the gears.
The Goal: We at Thirdinrev used a scanner to scan the gears, capturing the highest details with measurements such as pitch diameter, root angle, face angle, etc. and delivering the CAD file within required time (for this case - two days).
Reverse engineering is the process of duplicating an existing component, sub-assembly or product without the aid of drawings, documentation or an existing CAD file. It involves capturing technical details and composition of objects in order to improve, recreate or build upon the existing design.
One option of reverse engineering is where a CAD model can be designed by taking manual measurements of the component. But this gets challenging for complex designs where accuracy in angular measurements, curvature measurements, free-form surfaces and similar dimensions are of high importance and difficult to measure from conventional methods. Such measurements would take expertise, more time and high-cost measurement instruments.
The alternative option is to create digital copy of the component using either by Optical measurement systems (Laser scanners & Structured Light scanners) and by Tactile inspection systems (Touch probing).
We opted for an alternative of scanning the components using a structured light scanner. The output of scanning is Point-could data. After that it can be converted in as .STL, .obj, .wrl file formats. This file format which can later be converted to Solid model files like .iges, .step, .x_t, .sldprt, etc. This file can be easily editable in many common software such as Creo, Solid works, Fusion 360 and more.
The advantage of using a scanning technique for reverse engineering, creating digital copies or collecting measurement points are as follows:
Productivity - Such scanned files can be used to make design iterations and later on to 3D Print prototypes for testing or make small batches of components via low volume production or mass produced using various manufacturing methods available.
Accuracy - Scanning techniques provide an accuracy of ±5 microns to ±10 microns (depends on method used).
Speed - The process is very quick and takes no more than a few hours to days to get a fully watertight 3D CAD model.
Cost Effective - The cost is much lower than that of conventional methods which require high cost instruments for measurement and does not guarantee all measurements will be accurate due to human errors.
The process: The latest 3D Scanners are fast and accurate. The data is collected in the software and processed to form meshes. The output files as mentioned above are editable.
Conclusion: The client received a watertight, 3D Printable file which was edited to match their requirement. Once the final file was ready, they got it 3D Printed for testing with Thirdinrev in Metal material using DMLS 3D Printing technique. Once satisfied, the object went into low-volume production in the required quantity.