WaferMax T Mechanical-Bearing Direct-Drive Rotary Stage


Design Features

  • Low profile for space-conscious applications
  • Direct-drive, brushless, slotless servomotor
  • Direct-coupled, high-accuracy rotary encoder
  • 25 mm aperture
  • Optional rotary union for vacuum

Aerotech's WaferMax T rotary stage is an excellent choice for applications that require high performance in a low-height package. Originally designed for the demands of precision wafer inspection, the WaferMax T has been applied to a multitude of applications. A standard 25 mm aperture allows for easy pass-through of vacuum lines where limited rotation is required. If continuous rotation is necessary, an optional single- or dual-port rotary union can be incorporated. The tabletop includes a standard mounting pattern that allows for easy wafer-chuck mounting.

Superior Mechanical Design

Angular contact bearings are used to maximize performance with respect to wobble, moment stiffness and rotating friction. A thick-walled, precision-ground shaft further minimizes wobble.

Cable management is a snap with integral motor power and feedback connectors. Because the WaferMax T is a self-contained unit, it can be integrated easily into multi-stage stacks. Either a service loop or an integrated Aerotech cable management system (CMS) can be provided for a highly reliable solution.

Brushless Direct-Drive

To maximize positioning performance, the WaferMax T utilizes Aerotech’s S-series 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. Since it is a slotless, ironless design, there is zero cogging, meaning that there is absolutely no torque ripple. This makes the WaferMax T ideal for applications requiring outstanding contoured motion, smooth scan velocity or precise incremental steps. The low inertia and zero backlash make the WaferMax T the ideal solution for applications requiring frequent directional changes.

Accurate Positioning

Performance is assured with a 10,000 lines per revolution encoder that results in 0.065 arc sec resolution. A 2048 line option is also available. The motor and high-performance rotary encoder are directly coupled to a common shaft.

Flexible Configurations

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


WaferMax T Specifications

ModelWaferMax T
Travel 360 degrees, continuous
Tabletop Diameter 106.7 mm
Drive System Direct-drive brushless servomotor
Maximum Bus Voltage up to 340 VDC
Maximum Torque (Continuous) 5.99 N·m
Encoder 2048 lines/rev fundamental; 10000 lines/rev fundamental
Accuracy(1) HALAR ±25 µrad (±5 arc sec)
Bidirectional Repeatability ±10 µrad (±2 arc sec)
Tilt Error Motion 97 µrad (20 arc sec)
Axial Error Motion 5 µm
Radial Error Motion 5 µm
Maximum Speed 400 rpm (unloaded)
Maximum Load(2) Axial 40 kg
Radial 20 kg
Inertia 0.008130 kg·m2
Mass 7.0 kg
Material Aluminum
Finish Black Anodize
  1. Available with Aerotech controllers.
  2. Maximum loads are mutually exclusive.
  3. Specifications are for single-axis systems, measured 25 mm above the tabletop. Performance of multi-axis systems is payload and workpoint dependent. Consult factory for multi-axis or non-standard applications.
  • Axial and Radial Cantilevered Load Capability (WaferMax T)


  • WaferMax T

Ordering Information

Ordering Example

WaferMax T -RE2048AS -RU

Ordering Options

Series EncoderOptions
WaferMax T -RE2048AS

WaferMax T Direct-Drive Rotary Stage

Option Description
WaferMax T Direct-drive rotary stage with 25 mm clear aperture


Option Description
-RE2048AS Rotary encoder 2048 lines/rev; fundamental AS output
-RE10000AS Rotary encoder 10000 lines/rev; fundamental AS output


Option Description
-RU1 Rotary union for feed-through of air/vacuum, single port
-RU2 Rotary union for feed-through of air/vacuum, dual port
-GRND Adds grounding connection from tabletop