ABRT Air-Bearing Direct-Drive Rotary Stage


Design Features

  • High torque output, direct-drive, slotless, brushless servomotor
  • Zero-cogging motor for outstanding velocity stability
  • Outstanding error motion and wobble performance
  • Direct coupled, high-accuracy rotary encoder
  • Large diameter clear aperture
  • No mechanical contact

Aerotech's ABRT series rotary air-bearing stages provide superior angular positioning, velocity stability and error motion performance along with impressive payload capacity and outstanding radial and axial stiffness. The ABRT is designed to meet the exacting requirements of wafer inspection, high precision metrology applications, X-ray diffraction systems, optical inspection and fabrication, and MEMS/nanotechnology device fabrication.

Superior Mechanical Design

The ABRT design features large air-bearing surfaces and innovative preloading for high stiffness and load capacity, producing not only excellent axial and radial error motions, but outstanding tilt error motion, as well. The resultant performance is significantly better than other rotary air-bearing tables and spindles, greatly benefiting applications requiring exceptional planar performance. Furthermore, this stage family provides a clear aperture that can be used for product feed-through, laser beam delivery, cable clearance or application-specific requirements.

Brushless Direct-Drive

To maximize positioning performance, the ABRT series utilizes optimized versions of 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 ABRT stages ideal for applications requiring smooth scan velocities at low or high speeds.

Accurate Positioning

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

Custom Designs

Custom versions of the ABRT are available to satisfy rate table and high precision inertial guidance test-stand applications. Other features, such as slip rings and rotary unions, are available.

Flexible Configurations

Aerotech manufactures a wide range of servo amplifiers and advanced controllers to provide a complete, integrated package.


ABRT Specifications

Width 146 mm 196 mm 260 mm
Tabletop Diameter 100 mm 145 mm 200 mm
Height 135 mm 165 mm 185 mm
Aperture 20 mm 30 mm 50 mm
Total Travel 360° Continuous
Bus Voltage 340 VDC
Fundamental Encoder Resolution 11,840 lines/rev 18,000 lines/rev 23,600 lines/rev
Max Speed(1) 1200 rpm 800 rpm 600 rpm
Accuracy(2) ±2 arc sec
Repeatability <1 arc sec
Max Load(3) Axial 20 kg 41 kg 69 kg
Radial 3 kg 6 kg 10 kg
Tilt 3.5 Nm 8 Nm 18 Nm
Axial Error Motion (Synchronous) <100 nm
Radial Error Motion (Synchronous) <150 nm
Tilt Error Motion (Synchronous) <2.4 µrad (<0.5 arc sec)
Axial Error Motion (Asynchronous) <20 nm
Radial Error Motion (Asynchronous) <20 nm
Tilt Error Motion (Asynchronous) <0.2 µrad (<0.04 arc sec)
Operating Pressure(5) 80 psig (5.5 bar) ±5 psig (0.3 bar)
Air Consumption(6) <56.6 SLPM (<2 SCFM)
Inertia Unloaded 2300 kg·mm2 13,500 kg·mm2 46,400 kg·mm2
Total Mass 6.7 kg 14.7 kg 27.1 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

ABRT Air-Bearing Direct-Drive Rotary Stage

ABRT150 150 mm wide air-bearing direct-drive rotary stage
ABRT200 200 mm wide air-bearing direct-drive rotary stage
ABRT260 260 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.

Accessories (To Be Ordered As Separate Line Item)

-ABF Air-bearing filtration kit