Fast-tracking from physical to digital
01 November 2011
Point cloud data processing and 3D modelling software provides a rapid path for the re-design and production of the suspension arm for a one-eighth scale model racing car
R-Design Studio, a design and engineering firm based in Budapest, Hungary, refuses to be bound by conventions when it comes to finding the fastest path from design concept to final production. A recent project for R-Design’s Nimrod-Racing subsidiary is typical of the company’s approach. Faced with the challenge of redesigning the suspension arm for Nimrod-Racing’s Traxxas Slayer – a radio-controlled, one-eighth scale racing car model – R-Design’s engineers didn’t go back to the drawing board; they reached instead for their 3D scanner and Geomagic software.
First, the model car’s suspension arm was scanned by a GOM ATOS white-light scanner. This projects fringe patterns on the object's surface, which are then recorded by two cameras. The result is a triangulated mesh surface output as an STL file, which is then imported into the Geomagic Studio software to extract design intent. This software automatically identifies features such as planes, cylinders, cones, spheres, and extruded and revolved surfaces, enabling objects to be modelled as they were originally designed, with a combination of primitive shapes, swept features and freeform surfaces.
Once design intent was extracted, R-Design used Geomagic’s Parametric Exchange technology to directly transfer geometry from Geomagic Studio to SolidWorks. Parametric Exchange streamlines the design process by eliminating the need for intermediate neutral CAD transfer files such as IGES or STEP. Instead, 3D model data is transferred directly to popular parametric CAD systems where it can be edited immediately, as required.
The completed parametric model from Geomagic Studio was further refined in SolidWorks, where R-Design optimized the geometry and completed the redesign of the suspension arm using the CAD software’s built-in finite element analysis functions.
From digital to improved physical
The geometry was then sent to an Objet Eden 3D printer, which builds a part layer by layer with 16-micron accuracy, ensuring smooth surfaces and highly detailed parts. While the Objet printer is used primarily for manufacturing prototypes or finished parts, in this case it was used to create a silicon casting tool for R-Design’s vacuum casting system.
Within the casting system, carbon fibres and tapped inserts were placed into the silicon tool, which was filled with a special resin. The vacuum in the casting chamber enables the resin to completely fill the form, without bubbles. Small numbers of parts can be created – in this case, 100 pieces of the suspension arm – at a relatively low cost.
The combination of the optimised geometry created in Geomagic Studio and SolidWorks and the carbon-fibre composite material makes the new suspension arm ten times stronger while reducing its overall weight. Even if the car’s wheels collapse, the suspension arm won’t break.
The Nimrod-Racing project is a perfect example of R-Design’s ability to bridge the physical/digital divide in the service of speed and precision. And, if it takes breaking traditions, all the better for R-Design.
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