ABRS Air-Bearing Direct-Drive Rotary Stage


Design Features

  • Direct-drive, slotless, brushless servomotor
  • Zero cogging motor for outstanding velocity stability
  • Outstanding error motion and wobble performance
  • Direct coupled, high-accuracy rotary encoder
  • Low-profile planar design
  • No mechanical contact

Aerotech's ABRS series rotary air-bearing stages provide superior angular positioning, velocity stability and error motion performance in an exceptionally low-profile package. The ABRS is designed to meet the exacting requirements of wafer inspection, high precision metrology, x-ray diffraction systems, optical inspection and fabrication, and MEMS/nanotechnology device fabrication.

Compact Package

The design of the ABRS series direct-drive rotary stage has been optimized to minimize stage height. The low profile of the stage reduces the effective working height of the system, minimizing "stack-up" related errors. In addition to the low overall height, the ABRS series provides a clear aperture that can be used for product feed-through, laser beam delivery, cable clearance or application-specific requirements.

Superior Mechanical Design

The ABRS design features large air-bearing surfaces for high stiffness and load capacity, producing not only excellent axial and radial error motions but outstanding tilt error motion, as well. The resultant face error motion is significantly better than other rotary air-bearing tables and spindles, greatly benefiting applications requiring exceptional planar performance.

Brushless Direct-Drive

To maximize positioning performance, the ABRS series utilizes Aerotech’s S-series slotless, brushless motor. The motor uses an advanced magnetic circuit design to produce high torque output with minimal heat generation. The slotless design is inherently zero-cogging and torque ripple-free. This makes ABRS stages ideal for applications requiring smooth scan velocities at low or high speeds.

Accurate Positioning

An optical encoder is standard with the ABRS. When coupled with Aerotech's feedback multipliers and controls, resolutions of <0.03 arc second are achievable.

Custom Designs

Custom versions of the ABRS are available for rate table and inertial guidance test-stand applications.


ABRS Series Specifications

Width 150 mm 200 mm 250 mm 300 mm
Tabletop Diameter 128.1 mm 178.1 mm 228.1 mm 278.1 mm
Height 80 mm 90 mm 100 mm 110 mm
Aperture 8 mm 20 mm 35 mm 75 mm
Total Travel 360° Continuous
Bus Voltage 80 VDC 340 VDC
Fundamental Encoder Resolution 3600 lines/rev 8192 lines/rev 11,840 lines/rev 18,000 lines/rev
Max Speed(1) 300 rpm 300 rpm 500 rpm 500 rpm
Accuracy(2) ±3 arc sec ±2 arc sec
Bidirectional Repeatability <2 arc sec <1 arc sec
Max Load(3) Axial 8 kg 31 kg 66 kg 97 kg
Radial 4 kg 15 kg 36 kg 51 kg
Tilt 3 N-m 10 N-m 28 N-m 45 N-m
Axial Error Motion (Synchronous) <175 nm <100 nm
Radial Error Motion (Synchronous) <450 nm <250 nm
Tilt Error Motion (Synchronous) <9.7 µrad
(<2.0 arc sec)
<3.4 µrad
(<0.7 arc sec)
<2.4 µrad
(<0.5 arc sec)
<2.4 µrad
(<0.5 arc sec)
Axial Error Motion (Asynchronous) <20 nm
Radial Error Motion (Asynchronous) <20 nm
Tilt Error Motion (Asynchronous) <0.4 µrad
(<0.08 arc sec)
<0.3 µrad
(<0.06 arcsec)
<0.2 µrad
(<0.04 arc sec)
<0.2 µrad
(<0.04 arc sec)
Operating Pressure(5) 80 psig (5.5 bar) + 0 psig (0.0 bar)/-10 psig (0.7 bar)
Air Consumption(6) <56.6 SLPM (<2 SCFM)
Inertia Unloaded 3850 kg-mm2 13,800 kg-mm2 39,100 kg-mm2 102,000 kg-mm2
Total Mass 4.8 kg 9.1 kg 15.6 kg 24.5 kg
Material Aluminum
Finish Hardcoat (62 Rockwell Hardness)

  1. Maximum speed based on stage capability. Maximum application velocity may be limited by system data rate and system resolution.
  2. Certified with each stage. Requires the use of an Aerotech controller.
  3. Maximum loads are mutually exclusive.
  4. All error motion specifications measured at 60 rpm.
  5. To protect air bearing against under-pressure an in-line pressure switch tied to the motion controller is recommended.
  6. Air supply must be clean, dry to 0°F dew point and filtered to 0.25 µm or better. Recommend nitrogen at 99.9% purity.


Ordering Information

ABRS Air-Bearing Direct-Drive Rotary Stage

ABRS150MP 150 mm wide air-bearing direct-drive rotary stage
ABRS200MP 200 mm wide air-bearing direct-drive rotary stage
ABRS250MP 250 mm wide air-bearing direct-drive rotary stage
ABRS300MP 300 mm wide air-bearing direct-drive rotary stage

Feedback (Required)

-E1 Incremental encoder, 1 Vpp
-E2 Incremental encoder, TTL, x50 interpolation

Integration (Required)

Aerotech offers both standard and custom integration services to help you get your system fully operational as quickly as possible. The following standard integration options are available for this system. Please consult Aerotech if you are unsure what level of integration is required, or if you desire custom integration support with your system.

-TAS Integration - Test as system
Testing, integration, and documentation of a group of components as a complete system that will be used together (ex: drive, controller, and stage). This includes parameter file generation, system tuning, and documentation of the system configuration.
-TAC Integration - Test as components
Testing and integration of individual items as discrete components that ship together. This is typically used for spare parts, replacement parts, or items that will not be used together. These components may or may not be part of a larger system.