Product News: Introducing Shapetracer High-Accuracy Laser Line Scanner

For high-quality, noncontact reverse engineering and inspection

Published: Monday, September 27, 2010 - 14:53

(WENZEL Group: Wixom, MI) -- With the advent of 3-D technologies, requirements for quality assurance have increased. Previously, all major dimensions could be taken from a 2-D drawing for tactile measurement, but that is no longer the case. The curves of free-form surfaces are almost impossible to verify using traditional tactile measurement techniques, and 3-D drawings include little in the way of explicit dimensions.

WENZEL Group GmbH has developed advanced 3-D measuring technology to solve these measuring issues with its Shapetracer laser line scanner. The Shapetracer is a high-precision line scanner developed together with Pointmaster evaluation software from Wenzel Knotenpunkt. Shapetracer is an extremely compact scanner that can be connected to the Renishaw PH6M or PH10M probe head via the Renishaw Autojoint connection and, consequently, can be adapted to almost every coordinate measuring machine (CMM). In conjunction with the PH10M rotary swivel head, five-axis measurement is available.

From the outset, the Wenzel development team decided that the laser line scanner should be used on CMM with a stable support table, and not just on a mobile measuring arm. Higher production applications require automatic measurement of several workpieces, which is only possible on a large stationary measuring machine. In addition, if probe and sensor changing is automated, the Shapetracer can be cabled via the Renishaw Multiwire connection, so its storage together with other measurement heads is easily accommodated.

While scanning the workpiece, the operator is supported by the Pointmaster kinematics module and the software. The measuring machine can be virtually mapped so that simulations of the measuring process are possible. A point cloud is generated from the scan data, and from that a polygon model with a homogeneous surface is triangulated. The polygon model is converted into a CAD model in IGES format. Quality technicians receive this model, as well as CAD data, in IGES format from the design department. Using contrasting colors, Pointmaster highlights the differences between the two models; the variances in dimension can be discretionally selected and marked by flags. All dimensions are listed and contrasted in the evaluation protocol. This applies particularly to components with complex inner workings. These parts must be dissected to simulate both the external and internal contours.

With the Pointmaster software it is easy to construct a model from the component when scanned in different directions. The system provides functions for aligning the components and manufacturing homogeneous contour transitions to remove any cut surfaces and add consecutively scanned areas. Because the contours are assembled based on real data, a highly precise scanner is a prerequisite. After the CAD model is generated, the finest surface structures become visible. Ingrained lettering, for example, appears distinctly on the display screen.

“Shapetracer provides a measurement accuracy of better than 20 µm,” explains Giles Gaskell, sales manager for 3-D imaging products for Wenzel/Xspect Solutions. “This value is proven metrologically with verified calibration figures. Apart from the camera resolution, the accuracy of a laser sensor is primarily dependent on the depth of scanning. The greater the scanning depth, the more inaccurate the result. The Shapetracer is optimized for a scanning depth of 60 mm to obtain the specified accuracy.”

System overview

Dimensions: 100 x 68 x 58 mm
Working clearance: 40 mm
Scan width: 35 mm
Scan depth: 60 mm
Scan capacity: 48,000 points/sec
Measurement accuracy: better than 20 µm

“Because of its compact design, the Shapetracer is ideal for mounting in sensor changer systems, says Gaskell. “Consequently, any conventional measurement machine can easily be upgraded to become a multisensor machine,” Giles adds.

For more information, read the case study on Wenzel’s UK web site.

Housings for variable displacement pump are measured with the Wenzel Shapetracer.

About The Author

WENZEL Group

The WENZEL Group GmbH & Co. KG is one of the leading manufacturers of metrology solutions. The wide range of WENZEL products include solutions in the fields of coordinate measuring machines, gear metrology, computed tomography, design, die making, and reverse engineering. The main customers are in the automotive and aerospace industries, mechanical engineering, electrical motor manufacturing, and subcontractors to these sectors. The company has 16 subsidiaries worldwide and sales and service partners in more than 50 countries.