A New Reverse Engineering and Dimensional Inspection Service Digitizes Lamborghini's Washer Cover Flap

Today, reverse engineering technologies represent an indispensable instrument for cutting design times, obtaining high quality products and completing CAD/CAM and rapid prototyping technologies. In turn, reverse engineering closes the design loop: concept development-design-engineering-production. Three-dimensional scanners used for reverse engineering allow: complete digitization of a part’s surface, comparison with the original CAD model and generate a measurement report that highlights the dimensional discrepancies due to the production process.

A new reverse engineering and dimensional inspection service is available from CRP Technology (Modena, Italy), offering a qualified consultancy for 3D scanning, CAD modeling, dimensional inspection, components and equipments quality control. Equipment used includes a seven-axis CMM Faro Platinum Arm + Faro Laser Line Probe optical system. Other major activities from CRP include:

• HQ & HSM CNC (high-speed and high-quality machining with three, four and five axis)
• Rapid Casting (lost wax casting with RP patterns) in titanium, aluminum, steel alloys or superalloys
• New ULTRArapid Casting: the t rue rapid manu facturing technology; now available in aluminum alloys
• Rapid manufacturing and rapid prototyping services
• Rapid manufacturing and rapid prototyping composite materials production and sales
• Total quality management
• R&D: continuous research on materials like metallic alloys, plastic materials and new manufacturing processes development
• New reverse engineering

The Washer Cover Flap

In 2004, CRP Technology worked with Lamborghini S.p.A (S.Agata, Bologna, Italy), an Italian manufacturer of high performance sports cars, on the Gallardo Headlight Washer Cover Flap. In this case, a car-bodywork component was produced—in particular the washer cover flap of a high-performance vehicle, using selective laser sintering technology and CRP’s WindForm® XT material.

A first prototype was realized in a couple of days, starting from the 3D CAD files, which was useful when CRP needed to check resistance through several different work cycles. After the prototype’s realization, a specific dimensional inspection was made through large reference points on each piece—standard operation in Formula 1. It allowed CRP to guarantee, within defined tolerances, that the component profile would follow perfectly the specific housing.

Dimensional controls are usually performed using measurement instruments (calipers, height gages, thickness gages, coordinate measuring machines), which only manage to read some of the points and dimensions of the part being checked. This results in shape defects (twisting, dimensional shrinking) being hard to detect and quantify. Rather than use this process, the prototype was digitalized by a seven-axis Faro Laser Line Probe optical scanning system mounted on a Faro Platinum measuring arm. With a spherical measuring range of 3 m (10 ft.), a scanning speed of 19.200 points/second and a 0.05 mm 2Û accuracy in non-contact measurements, the combined use of the seven-axis arm and the laser scanning system allowed contact measurements or optical scanning to be done simultaneously inside the same reference system. The lightness of the tool plus the high number of freedom degrees made measurements quick and reliable even of complex, hard to reach parts.

The Results

By managing the entire quality control process in virtual environment, highly detailed measurement reports were produced (color- range mapping, cross sections, statistic error reports) with considerable time savings. Finally, the quality control results were useful for correcting and improving the manufacturing process. For example, in the case of rapid prototyping, building parameters can be optimized according to the shape and thickness of the parts to be made—all you have to do is build a first test prototype, perform the scan and then calibrate the rapid prototyping machine again according to the dimensions to be “offset.”