ASRT Series Mechanical-Bearing Direct-Drive Sealed Rotary Stages


Design Features

  • IP66: Totally protected against dust and water jets from any direction
  • Operation over large temperature range: -20 to +70° C
  • Low-friction seal minimizes direction reversal hysteresis to allow small, precise positioning
  • Shaft aperture option with three available sizes: 30 mm, 80 mm, and 130 mm
  • Excellent accuracy (to 2 arc sec) and repeatability (to 1.5 arc sec)
  • Axial load capacity to 130 kg
  • 100-200 rpm continuous rotation speed
  • Direct-drive motor provides rapid precision motion with no gear backlash

ASRT sealed rotary stages provide precise angular positioning in hostile environments where dirt or liquids are present. The stage can operate in environments with dust or fluid jets. The ASRT also can be used where cutting fluids are present. Applications range from industrial machining automation to precision sensor positioning in hostile environments. The ASRT is effective for precise rotary motion in product environmental test and range tracking applications.

The ASRT series is available in three different sizes for a variety of load and motor torque ratings. A shaft aperture option on all sizes allows for electrical, pneumatic, or fluid feedthrough. Offered with a high-accuracy optical (incremental or absolute) non-contact encoder or with a robust magnetic non-contact encoder, the ASRT has many feedback options to meet the specific requirements for many tough applications.

Standard operating temperature for the ASRT is 0 to 70°C. Operation below freezing requires the optional air-purge and dessicant. Air-purged stages can operate from -20 to 70°C.

A polymer-based paint on the housing and hard-coated tabletop is standard for corrosion protection. The stage has optional tan, black, and white paint colors.

Rotary speeds of 100 to 200 rpm are available. The ASRT includes an electrically grounded shaft and housing to protect against electrical shock and eliminate RF re-radiation, and housing grounding points are included. Circular sealed connectors are standard, while options include desiccant cartridge, air purge option, and mounting flange accessory.

Superior Mechanical Design

Dual large-diameter bearings are used to maximize performance with respect to tilt error motion, moment stiffness, and repeatability. The large diameter bearings permit large payloads without compromising performance.

Brushless Direct-Drive

To maximize positioning performance, the ASRT series utilizes Aerotech’s brushless, slotless motor. This motor has all of the advantages of a brushless direct-drive motor – no brushes to wear, no gear trains to maintain, and high acceleration and high speeds. The low inertia and zero backlash make the ASRT the ideal solution for applications requiring frequent directional changes.

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


ASRT Series Specifications

Travel 360° Continuous
Accuracy(1) (-O) Optical Encoder (-O/-O-ABS) Standard 194 µrad (40 arc sec) 145 µrad (30 arc sec) 97 µrad (20 arc sec)
HALAR 10 µrad (2 arc sec)
Magnetic Encoder (-M) Standard 243 µrad (50 arc sec) 218 µrad (45 arc sec) N/A
HALAR 97 µrad (20 arc sec) 97 µrad (20 arc sec) N/A

(Min. Incremental Motion)

Optical Encoder (-O) 0.5 µrad (0.1 arc sec) 0.4 µrad (0.08 arc sec) 0.03 µrad (0.06 arc sec)
Optical Encoder (-O-ABS) 0.8 µrad (0.16 arc sec) 0.8 µrad (0.16 arc sec) 0.8 µrad (0.16 arc sec)
Magnetic Encoder (-M) 12.1 µrad (4 arc sec) 11.2 µrad (3 arc sec) N/A
Bidirectional Repeatability(1) Optical Encoder (-O) 7.3 µrad (1.5 arc sec)
Optical Encoder (-O-ABS) 7.3 µrad (1.5 arc sec)
Magnetic Encoder (-M) 73 µrad (15 arc sec) N/A
Total Tilt Error Motion(1) 24 µrad (5 arc sec)
Maximum Speed(2) 200 rpm 150 rpm 100 rpm
Maximum Acceleration(2) 930 rad/s2 635 rad/s2 425 rad/s2
Aperture 30 mm 80 mm 130 mm
Maximum Torque (Continuous) 2.85 N·m 5.99 N·m 10.73 N·m
Load Capacity Axial 30 kg 105 kg 130 kg
Radial 25 kg 90 kg 110 kg
Inertia (Unloaded) No Aperture 0.009 kg·m2 0.034 kg·m2 0.091 kg·m2
Aperture 0.011 kg·m2 0.036 kg·m2 0.100 kg·m2
Stage Mass No Aperture 9.5 kg 17 kg 22.5 kg
Aperture 12.0 kg 20.5 kg 27.0 kg
Material Polymer-Painted Aluminum / Aluminum Hardcoat
MTBF (Mean Time Between Failure)(3,4) 10,000 Hours
  1. Certified with each stage.
  2. Application dependent. Requires the selection of an appropriate amplifier with sufficient voltage and current.
  3. Application dependent. Dry environments between 0° and 70° C up to 10,000 hours.
  4. Long-term exposure to temperature cycles and wet environments will require periodic maintenance.

Electrical Specifications

Drive System Slotless, Brushless, Direct-Drive Rotary Motor
Feedback System Incremental Optical (-O) 1 Vpp, Incremental Non-Contact Optical Encoder
16384 lines/rev 23600 lines/rev 32768 lines/rev
Absolute Optical (-O-ABS) Absolute, BiSS Interface, Non-Contact Optical Encoder
Magnetic (-M) 1 Vpp, Incremental Non-Contact Magnetic Encoder N/A
900 lines/rev 1200 lines/rev
Maximum Bus Voltage 320 VDC

Recommended Controller

Multi-Axis A3200 HLe-MXH/HPe-MXH/CP-MXU/MP-MXU/CL-MXU/Npaq
Single Axis Soloist HLe-MXH/HPe-MXH/CP-MXU/MP-MXU/CL-MXU
  • ASRT Axial and Radial Cantilevered Load Capability
    Axial and Radial Cantilevered Load Capability


  • ASRT185DR
  • ASRT185DR-A
  • ASRT245DR
  • ASRT245DR-A
  • ASRT300DR
  • ASRT300DR-A

Ordering Information

Ordering Example

ASRT185DR -O   -PV3 -F2  

Ordering Options

Model/OptionsEncoderAccessoriesExterior Color/Mounting OrientationFlange Mounting KitCover Shroud Kit



ASRT Series Rotary Stage

Option Description
ASRT185DR Direct-drive sealed rotary table; 185 mm wide
ASRT185DR-A Direct-drive sealed rotary table with 30 mm aperture; 185 mm wide
ASRT245DR Direct-drive sealed rotary table; 245 mm wide
ASRT245DR-A Direct-drive sealed rotary table with 80 mm aperture; 245 mm wide
ASRT300DR Direct-drive sealed rotary table; 300 mm wide
ASRT300DR-A Direct-drive sealed rotary table with 130 mm aperture; 300 mm wide

Encoder (Required)

Option Description
-O Optical incremental encoder option (1 Vpp output)
-O-ABS Optical absolute encoder option
-M Magnetic encoder option (1 Vpp output); Not available on the ASRT300DR

Accessories (Optional)

Option Description
-AP Air purge kit
-D Desiccant cartridge kit

Exterior Color / Mounting Orientation (Required)

Option Description
-PV1 Desert tan; vertical axis of rotation
-PV2 Black; vertical axis of rotation
-PV3 White; vertical axis of rotation
-PH1 Desert tan; horizontal axis of rotation
-PH2 Black;horizontal axis of rotation
-PH3 White; horizontal axis of rotation

Flange Mounting Kit (Optional)

Option Description
-F1 Desert tan; flange kit
-F2 Black; flange kit
-F3 White; flange kit

Note: Vertical mounting orientation only

Cover Shroud Kit (Optional)

Option Description
-C1 Desert tan; cover shroud kit
-C2 Black; cover shroud kit
-C3 White; cover shroud kit

Note: Horizontal mounting orientation only