3D scanning speeds production of custom roof racks

Situation

Started as Cali Raised LED in 2014, Hamar Industries Inc. was incorporated in 2018 in Fort Worth, Texas, as a one-stop job shop for aftermarket vehicle accessories and custom metal fabrication, including laser cutting, bending, and welding.

One of the company's most in-demand services and specialties is building custom-fitted roof racks. Designed to support a large amount of weight with a minimal number of contact points, the racks must be engineered to minimize wind noise; reduce drag; and withstand high speeds, sudden stops, and turns.

The most important element, however, is getting the right fit. To accomplish that, it’s necessary to determine, as accurately as possible, the precise geometry of the vehicle’s roof and any possible interferences. "The contour of the roof is important for a great overall fitment,” explained Chris Pelley, vice president of operations and engineering. “Location of all mounting locations is also very important to making the roof rack install easily for our customers. We are also looking to avoid conflict with any factory accessories or features like sunroofs, windshield wipers, rear hatches, and doors.”

The company first considered using 3D scanning while developing custom roof racks for three Toyota vehicles: the Tacoma, the Tundra, and the 4Runner. Because these racks fit extremely tight to the roof and Hamar needed an accurate roof profile in about 12 spots, the company determined that 3D laser scanning would provide the most geometrically correct representation of the roofs.

Resolution

Hamar contacted NVision Inc., a 3D measurement and engineering services company with work in the auto/transportation sectors that includes the rapid design and reverse engineering of motorcycles, autos, trucks, trailers, and automotive products. Over the course of four business days, NVision technicians performed scanning on-site at Hamar, focusing on the three vehicles’ roofs down to the tops of all the windows, using the NVision HandHeld scanner.

The portable scanner captures 3D geometry from objects of almost any size or shape. It’s attached to a mechanical arm that moves about the object, allowing the user to capture data rapidly with a high degree of resolution and accuracy. As the object is inspected, the scanner generates a point cloud comprising millions of points, each with XYZ coordinates and IJK vectors. These points comprise an exact duplicate of the object’s surface, down to minute details.

The scanner comes with integrated software that is used to convert the point cloud to an STL polygon, and an optional tripod provides portability in the field. Intuitive software allows real-time rendering, full model editing, polygon reduction, and data output to all standard 3D packages.

The technicians performed four scans of every roof, with each scan comprising a quarter of its surface (driver’s side front, passenger’s side front, driver’s side rear, and passenger’s side rear). They then did a basic postprocessing cleanup to remove unneeded data and aligned the four different roof scans to produce a composite point cloud of each roof, using reference spheres.

After the technicians polygonated the raw point cloud data into an STL file, that file was used as a template to create design intent CAD models in IGES and STEP format. Hamar imported the models into its in-house CAD software to interface with models of final roof racks to check for form, fit, and function.

The ability of 3D laser scanning to quickly capture complex geometries helped Hamar achieve optimal designs for its roof racks in a quick completion time, allowing the company to begin selling the racks that much sooner.

"Without the scans, we would have extended our R&D and production time by 300%," said Pelley. “The 3D scans … paid for themselves in time reduced in the R&D process.

“NVision provided us with the 3D CAD models we needed to launch three product lines,” he concluded. “Having the quality scans import seamlessly into our in-house CAD software made design and testing very easy and very fast.”