Quality Applications

FARO Technologies Inc.'s FaroArm Gold 12 CMM Benefits Multi-axis measurement Features a reach of up to 12.14 ft (3.7 meters) Weighs just 31 lb (14 kilograms) www.faro.com

FaroArm Expands BMW's Measurement Process
FARO Technologies Inc.'s FaroArm Gold 12 CMM

BMW was looking to update its metrology processes at its Regensburg plant in Germany. Too many plant-floor measuring applications couldn't be carried back to the quality control department. Additionally, many of these applications, particularly on the production line, weren't easily accessible by conventional coordinate measuring machine systems.

 To solve the problem, BMW sought to implement a flexible and mobile metrology system. The automaker got both with its selection of the FaroArm Gold 12 CMM system. The FaroArm uses precision encoders to accurately measure the exact position of the arm's probe tip regardless of the user's approach to the measured part or assembly. Because the quality control department uses BMW's standard measuring software, little additional training was needed for using the FaroArm. As a result, the FaroArm was soon introduced throughout the plant.

 In production, convertible hardtops have to fit any convertible body coming down the line. Equally important, fit and wind-noise levels have to meet BMW's strict standards. Unfortunately, while hardtops were easily installed, they were not tight in all cases. To remedy this, inspectors set up the FaroArm on the master body-in-white to examine and check the hardtop's mounting hardware, the matching components on the car and the sealing channel for the windows. They then used the FaroArm to examine the window and hardtop fit on 20 finished vehicles. Last, they used the FaroArm to check the location and security of the attached mounting points for the hardtop.

 The results were unmistakable: The prepositioning of the car's side windows was causing production problems. Quality control was able to optimize the prepositioning of these windows in such a way that not only solved the fit problem but also became a more efficient way of mounting the hardtop.

 Another measuring application involved checking the location of headlights in the car's front-end subassembly. Obviously, the subassembly couldn't be brought to the quality control department. Instead, the department and its metrology equipment had to go to the assembly line. Using FaroArm, headlight location is now verified at the final assembly site. BMW already has plans to use FaroArm to measure other aspects of a vehicle while it's in production and relatively inaccessible to a CMM.

 The FaroArm also helps BMW's suppliers. Many suppliers bring their parts to BMW-Regensburg for verification by in-house quality control personnel. The flexibility of the FaroArm lets the quality control department measure these parts inside the master body-in-white. In so doing, the department and the suppliers can easily determine if errors or out-of-tolerance situations exist in the supplier's part or the BMW design.

 BMW forsees additional uses for FaroArm, especially for measuring gaps and seams. At present, many of these are checked visually or with hand-held feeler gages because fixed touch probes are difficult to use to properly locate the highest point of an edge. In the case of a seam, the tip of the touch probe may be too big to make accurate contact; precise seam dimensions can now only be measured with CMMs. The current FARO approach to this problem uses a touch probe adapter produced by Renishaw for high-end CMMs. BMW hopes eventually to outfit a FaroArm with a laser scanner and camera to automate and more accurately measure gaps and seams right there on the production line.

 The consistent theme in all of these measuring applications is having the flexibility to control dimensional quality throughout a manufacturing plant--and not just in a special quality control room. BMW got that once it chose a portable, measure-anywhere CMM tool.