US-based Lear Corporation has realised savings of $240,000 injust one seat manufacturing programme by replacing atemplate-based inspection system with a laser scanning one. Using3D Scanners' ModelMaker software, Lear inspects automotiveseats during design and manufacturing. Before, Lear compared asample seat with a series of contoured plastics templates whichshoed the original styling guidelines.

Typically nine templateswere needed for each seat, and the seat had to line up within 6mmunder manual 'GO, NO-GO' inspection.

Total templatecost for a seat programme with 29 seat configurations was some$104,000.

An inspection stand could cost $22,000 and fivedifferent stands would be needed.

Two sets of stands - costing$220,000 - would be needed if a seat style were produced in twodifferent factories.

Lear chose the ModelMaker system, whicheliminated the templates and the stand cost is now $15,000instead of $22,000.

The system is based on a 3D laser sensor, aposition-sensing device on which the sensor is mounted, a PC andsoftware.

The software extracts displays and manipulates thesensor data.

Lear chose the FaroArm with seven degrees of freedomto reach any point in the seat.

In operation, the sensor ispositioned to show a laser light line across the seat, and ismoved across the area to be checked and the data is displayed onthe PC screen.

Laser scanning is much faster than making templatemeasurements, so Lear now scans a number of customer-approvedseats and averages the data to set manufacturing tolerances.Scanning provides real X, Y and Z co-ordinates.

If a seat area isout of tolerance, manufacturing personnel can see exactly howmuch it is in error.

The scanning system is more accurate thanthe template system (gaps between template surfaces and seatareas would have to have been measured manually) and readilywarns of any drift away from the 'mean'.

Also thescanning system is immediately adaptable to seat modifications.