A line of dual-axis linear motors from Baldor Electric Co., Fort Smith, Ark., the HoneyComb Series, uses linear stepper motors to drive an XY base. The motor comprises two parts, a forcer that generates motion and a base or platen that performs two-axis moves.
Honeycomb-structure and composite material in the base lets the forcer directly drive the base, an alternative to traditional rotary motors driving ball screws or belts. Seven standard base sizes range from 375 375 mm to 750 1,500 mm. The honeycomb structure also makes the base up to 70% lighter than comparable models without compromising stiffness. The flatness of the base deviates less than 14 μm across its surface.
Six forcers range from 80 to 178 mm square and come in two and four-phase configurations, depending on force and resolution requirements. Two linear stepper motors mounted at right angles to each other in the forcer drive the base at speeds up to 1.5 m/sec with resolutions of 2.5 μm and repeatability better than ±2 μm. An air bearing between the forcer and platen produces near friction-free motion with zero backlash and no wind-up. Maximum static holding force is up to 134 N.
Multiple forcers can mount on the same base with overlapping trajectories if needed. The low weight of the honeycomb structure lets the base be used vertically or face down. Total mass with platen and forcer start at less than 10 kg.