"So we were tack welding large pieces in place as close as we could using manual methods, and then taking them to the CMM for more accurate measurements," says Doug Phillips, quality analyst with Volvo. "We'd measure one half, take it out of the machine, turn it around, and measure the other half, and often several times."

Volvo engineers solved the measurement problems with the FaroArm, a portable CMM from Faro Technologies Inc., Lake Mary, Fla. It can roll up to the 16-ft weldments and still measure them to within 0.0076 in.

The arm includes a laptop computer and software for inspection and measurements. Users identify and verify locations of reference features such as holes, spheres, and arcs. Because the software draws features as they are measured, process control is instantaneous. In addition, the arm can measure surfaces with hole patterns and complex curves. The software also compares part to their prints or design files.

Scott Valentine, senior quality engineer with Volvo, recently laid out a new 50-ton hauler and says the 120 hr needed by quality assurance on smaller loaders was reduced to 30 hr on the larger one. What's more, the new device eliminates the 40 hr usually spent hustling large weldments from assembly stations to the stationary CMM.