QMT Features: January 2008
Digital head start
Thule Towing Systems shifted from a predominantly manual process to developing towbar systems using laser scanning and mechanical design/simulation software, cutting time to market from 15-20 weeks to approximately 9 weeks.

Thule – a global leader in sports utility transportation – is one of the major towbar system manufacturers in the world. Following Thule’s 2006 acquisition of the Dutch towbar manufacturer Brink International, the Thule Towing Systems business unit for Europe/Asia operates from Staphorst in The Netherlands.

Thule Towing Systems develops and manufactures towbar systems for vehicle OEMs as well as for the car after market. For a new vehicle that will soon hit the market place, Thule engineers start with taking a detailed 3D scan of the bottom end of the vehicle, the area where the new towbar system needs to be incorporated.

They use the Metris ModelMaker scanner – mounted on an articulated measurement arm – and manually scan the area of interest, which typically includes bumper, fuel tank, muffler, spare wheel, chassis sections, etc. The scanner’s high frame rate and wide laser stripe make that the area is scanned quickly and precisely. The resulting 3D surface scan takes shape in real time, which makes it easy to track scan coverage and progress. The fully portable Metris ModelMaker system can be used internally at Thule just as easily as at customers’ sites, saving vehicle transportation time and cost.Thule engineers use Metris ModelMaker laser scanner to create a digital 3D copy of a new vehicle’s rear end.

Thule engineers use Metris ModelMaker
laser scanner to create a digital 3D
copy of a new vehicle’s rear end.
“Our prime objective with Metris ModelMaker is digitizing the space that is available to integrate the towing system,” says Thule After Market development department at Thule Towing Systems in Staphorst, The Netherlands. “For us, the graphic 3D surface scan represents critical engineering input right at the start of the towbar development process. In this way, we immediately see where we can fit particular mechanical parts of different shapes and sizes in order to design the assembly that attaches the towbar to the vehicle chassis. Formerly, we had to spend lots of time consulting CAD files we received from auto manufacturers, which contain much irrelevant data as well as information items that have become outdated.”

Metris ModelMaker is a digital laser scanner combining superior stripe resolution with one of the highest effective throughput rates available on the market place. This allows surface features to be captured accurately. Thule engineers apply this detailed feature scanning capability to verify the location of towbar system attachment points on the chassis of the vehicle. While scanning, the scanner additionally adapts the power of its laser beams to account for varying shape, colour and reflectivity. This makes that the entire scan can be executed without having to manually adapt scanner settings.

Feeding facts into the development process
The result of the scan is a cloud of hundred thousands or even millions of measured surface points that is managed efficiently in the Metris Kube software. “In the Metris Focus Reverse Engineering software, we filter the point cloud to eliminate excess points and transform the point cloud into a polygon surface mesh,” Thule After Market development department explains. “Then we export the entire 3D surface – including both free-form areas and features – into Pro/Engineer, our mechanical engineering and design CAD tool. From a designers’ perspective, it is great to see the 3D surface you just scanned in your design software environment and look at it from any preferred standpoint. It is so realistic that it feels like working on the real vehicle, while benefitting from a higher degree of design efficiency.”

Thule After Market development department says that this digital approach allows Thule design engineers to quickly try different design concepts, and further elaborate on the most promising towbar configurations. “Ultimately, this results in a better towbar design that costs less and is often more elegant,” Thule After Market development department explains. “Besides reducing towbar weight and welding effort/material, the engineering process increases manufacturability and lowers the number of recalls. In the past, we had to quickly handicraft a towbar assembly mockup based on tape measurements throughout the day the vehicle was made available to us. Since the digital process is put in place, there is far less work in our workshop. In fact, the first physical tests of newly designed towbars have proven OK immediately, eliminating multiple physical testing rounds overall.”

Thule After Market development department states that the use of Metris ModelMaker laser has  updated its development process, helping to compress time to market from 15-20 weeks to only 9 weeks - in addition, towbar system quality has further improved. Such significant time saving, along with a better engineered and easier to manufacture product, reduces cost considerably.


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