Reverse Engineering Using 3D Scanners to Generate CAD Models
The engineers of today lives and thrives in a 3D CAD model world. The CAD models offer the best design versatility and a direct link to rapid prototype development. The CAD models are essential where reverse engineering use 3D scan data to generate CAD models.
Here, the object exhibits a complex shape when using a 3D model that does not exist for a component. The 3D scan equipment captures the physical geometry that transforms it into a 3D digital model. The CAD engineers and industrial designers create a task to adapt and maintain parts that integrate into the design.
Reverse Engineering Features:
Designing a new part to fit a legacy part.
Obtain CAD data that captures an object's design intent.
It accurately offers performance surfaces.
It helps in updating CAD models of your tooling to match shop-floor changes.
Get ready to redesign a part without manufacturing defects.
It supports modernising your manufacturing process.
It offers animation or visualisation.
Perform a dimensional along with comparative analysis of an object.
Performing FEA or CFD analysis.
Reconstruct the damaged part digitally to reproduce it in its originally intended form. It uses rapid prototyping or CNC technologies. The 3D scanning technologies come in different shapes and forms. Additionally, some stationaries require the part to be brought into the scanner.
The scanning laser technology has conducted surveys of the 3D contour of the surface. It helps to save the geometrical data to a CAD model. The 3D scanners scan vehicles, aeroplanes, ships, submarines, historic monuments, buildings, sculptures, consumer products, and more.
Let's say a complex 3D scanning problem is the 3D scan that is performed by Creaform, mainly using HandyScan3D. It's a unit combined with a long-range scanner in the United States Marine Corps War Memorial replica. It is located at the Marine Corps Recruit Depot in South Carolina.
The project's primary purpose comes with historical preservation so that the memorial could recreate in the future if it suffers damage. The handheld scanner mostly used the application capable of scanning ½ million points per second. With up to 30 sq. resolution accuracy and 60 sq. volumetric accuracies.
HOW DO 3D SCANNERS WORK?
Laser scanning is a process where the scan passes a laser line over the surface of an object. Later the surface data was captured by a camera sensor mounted in the laser scanning. It records and saves three-dimensional information to a model.
The regions of an object are scanned once. It allows thousands of closely positioned points to be surveyed at once. Currently, several laser scanners exist, including the line, patch, and spherical. Also, Laser scanning is performed without making contact with the object.
Talking about digitising, it's a contact-based form of 3D scanning in which a point or ball probe is scanned over points on the object's surface. It is more accurate for industrial reverse engineering applications. The 3D laser scanning is more desirable for non-standard or organic shapes where the sculptures or person's face is scanned. Digitising limits to smaller objects, while 3D laser scanning is more versatile.
It is used to scan large objects like vehicles or buildings. White light scanning, CT scanning and photo image-based systems are mainly used as alternate methods for 3D scanning applications.
LIMITATIONS OF 3D SCANNING
Bright white light sources can be detrimental to 3D scanning technologies, requiring many outdoor laser scanning projects to be conducted after daylight hours.
3D scanning works better on matte finishes than highly reflective surfaces, which reflect white light. Spray-on solutions exist that can effectively dull a surface before scanning.
Some intricate objects, such as large sculptures, require stationary and handheld scanners to reconstruct the entire surface. This process requires a detailed and intricate image and position registration – fortunately, many companies exist that have mastered this process and provide solutions for these complex problems.
INSPECTION WITH USING 3D SCANNING TECHNOLOGIES
Inspection is another valuable use of 3D scanners. It allows parts to be rapidly checked and ensures manufacturing tolerances. 3D scanning technologies use First Article Inspection, where high accuracy comes with fine resolution. It requires verification with a physical part that produces according to production drawings.
The scanners inspect a "final" part so that its models and drawings can generate blueprints for re-manufacturing a part. The Inspection of aging components or systems is possibly used with technologies. For example, modifications are required to update the vehicle in foraging ships or aircraft. It uses reverse engineering that uses laser-based 3d scanning technologies that produce physical dimensions of the vehicle or its parts.
It comes with a prime example that comes with reverse engineering. It comes with an F-15 test plane used for NASA engineers. It was conducted by Direct Dimensions, Inc. (DDI) in 2006. Additionally, the engineers at NASA modify the test plane and obtain in-flight data to verify design improvements.
Due to its daunting costs, it associates along with full-scale testing. It comes with the danger associated with measuring pressure on a plane that moves at supersonic speeds. It is used to chase planes with the help of reverse engineering. Before testing and implementation, it could simulate the design changes and use computational fluid dynamics (CFD) software. DDI mainly uses the FARO LS 3D laser system, along with a portable scanner designed for scanning the shape of large objects.
It can acquire up to 120,000 points per second over ranges of up to 80 meters. The technology allows DDI and quick and accurately capturing the jet's exterior shape with an accuracy of +/-6 millimeters. The raw comes with 3D scanning data that offer a high-resolution point cloud. It uses a laser that reflects spots off the plane's surfaces. It can digitally process and convert to CAD format. Over 50 individual scans from different positions generated 50 million data points used in reverse-engineering of the F-15.