The direct drive is faster than worm gears (45 to 300-rpm continuous rotation) with no gear wear or vibration. The stage is 65 to 160-mm tall and uses a brushless, slotless motor that has high acceleration and high speeds. Axial-load capacities can reach 1,000 lb. A 31,000 or 74,000-line-count encoder maintains accuracy to ±3.9 arc-sec with bidirectional repeatability of ±0.5 arc-sec.

Aerotech Inc., 101 Zeta Dr., Pittsburgh, PA 15238, (412) 963-7470,