ASRT 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
  • Up to 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 up 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) -E1 or -E2 Encoder Standard 194 µrad (40 arc sec) 145 µrad (30 arc sec) 97 µrad (20 arc sec)
Calibrated 10 µrad (2 arc sec)
-E3 Encoder Standard 243 µrad (50 arc sec) 218 µrad (45 arc sec) N/A
Calibrated 97 µrad (20 arc sec) 97 µrad (20 arc sec) N/A

(Min. Incremental Motion)

-E1 Encoder 0.5 µrad (0.1 arc sec) 0.4 µrad (0.08 arc sec) 0.03 µrad (0.06 arc sec)
-E2 Encoder 0.8 µrad (0.16 arc sec) 0.8 µrad (0.16 arc sec) 0.8 µrad (0.16 arc sec)
-E3 Encoder 12.1 µrad (4 arc sec) 11.2 µrad (3 arc sec) N/A
Bidirectional Repeatability(1) 7.3 µrad (1.5 arc sec)
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 -E1 Encoder 1 Vpp, Incremental Non-Contact Optical Encoder
16384 lines/rev 23600 lines/rev 32768 lines/rev
-E2 Encoder Absolute, BiSS Interface, Non-Contact Optical Encoder
-E3 Encoder 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/Npaq
Single Axis Soloist HLe-MXH/HPe-MXH/CP-MXU/MP-MXU
  • ASRT Axial and Radial Cantilevered Load Capability
    Axial and Radial Cantilevered Load Capability


Ordering Information

ASRT Mechanical-Bearing Direct-Drive Sealed Rotary Stage

ASRT185DR ASRT185DR mechanical-bearing direct-drive sealed rotary stage, 185 mm frame size
ASRT245DR ASRT245DR mechanical-bearing direct-drive sealed rotary stage, 245 mm frame size
ASRT300DR ASRT300DR mechanical-bearing direct-drive sealed rotary stage, 300 mm frame size

Aperture (Optional)

-A Clear aperture thru stage; 30 mm (ASRT185DR); 80 mm (ASRT245DR); 130 mm (ASRT300DR)

Feedback (Required)

-E1 Incremental optical encoder, 1 Vpp
-E2 Absolute optical encoder
-E3 Incremental magnetic encoder, 1 Vpp

Note: -E3 feedback option not available with ASRT300DR

Exterior Paint Color (Required)

-PNT1 Desert tan
-PNT2 Black
-PNT3 White

Mounting Orientation (Required)

-MT1 Vertical axis of rotation
-MT2 Horizontal axis of rotation

Air Purge (Optional)

-PR Air purge

Desiccant Cartridge (Optional)

-DSC Desiccant cartridge

Flange Mounting (Optional)

-F Flange mounting kit

Note: -F flange mounting kit available only with -MT1 mounting orientation.

Cover (Optional)

-CV Cover shroud kit

Note: -CV cover shroud kit available only with -MT2 mounting orientation.

Metrology (Required)

-PL1 Metrology, uncalibrated with performance plots
-PL2 Metrology, calibrated (HALAR) with performance plots


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. This is typically used for spare parts, replacement parts, or items that will not be used or shipped together (ex: stage only). These components may or may not be part of a larger system.