A new line of coordinate measuring machines features a wide tracking range and uses a stable design to eliminate movement errors. Mitutoyo?s Legex line has three models that cover a range of 28 to 36 inches in the x-axis, 28 to 40 inches in the y-axis, and 18 to 24 inches in the z-axis. Center-of-gravity ballscrew drives and a fixed-bridge moving-table design reportedly rid the Legex of pitch and yaw errors. Movement is steadied by low-lift air bearings that ride on hand-lapped steel guides with a standard air server. The server filters and controls bearing air-supply temperatures to ±.1 deg C. The CMM?s base is constructed from cast iron, creating a stable platform. Drive couplings and motor mounts are isolated to minimize internal vibration. For external vibrations, Legex uses an air-damped, auto-leveling, vibration-isolation stand.
The unit?s crystal-glass linear encoders have a resolution of ±.01 µm with a near-zero thermal coefficient of expansion. The bearings are situated to remain independent of any thermally induced linear movements of the steel structure.
In terms of accuracy, the Legex?s 3-D volumetric is 1.5 µm over 1m, and the unit has a static average measuring mode that eliminates residual dynamic influences. Compared to a touch-trigger probe, the Legex can reportedly scan complex contours at submicron accuracies more quickly.
Legex is capable of scanning, point-to-point, and noncontact measurements, and it uses the full series of Renishaw indexing heads, probes, and changers. Scanning can be handled by a Renishaw SP600M analog probe or a Mitutoyo high-resolution, digital scanning head. A Renishaw-compatible video probe provides noncontact measuring of holes and surface lines.
Legex comes with GeoMeasure CNC software and ScanMeasure software. ScanMeasure performs reverse engineering and scanning of prismatic parts and complex geometry, while GeoMeasure brings together measurements, scans, and CAD imports into a flexible output mode.
Mitutoyo America Corp., Aurora, IL