ALAR Mechanical-Bearing Direct-Drive Rotary Stage

Description

Design Features

  • 5 different aperture sizes: 100 mm, 150 mm, 200 mm, 250 mm, 325 mm
  • Axial load capacity up to 595 kg; radial loads to 680 kg
  • Excellent accuracy and repeatability
  • Cog free motor provides smooth motion
  • No gear backlash; no accuracy changes over time from gear wear
  • 45-300 rpm continuous rotation speed
  • Vacuum compatible versions available

Aerotech’s ALAR series direct-drive rotary stages provide superior angular positioning and velocity control with exceptionally large apertures. With the combination of a large aperture and direct-drive motor, the ALAR series makes worm-drive large aperture stages a thing of the past.

Advantage ALAR

Now customers can get large aperture rotary stages with zero backlash and no gear wear or gear vibration as is commonly seen in worm-drive stages. The other added benefit is that direct drive is significantly faster than worm drive, so testing can be completed in less time. In production settings, this equates to faster testing, lower cost manufacturing and higher profits. From the standpoint of system accuracy and repeatability, the stage will maintain its performance over time with no need for maintenance because there are no gears to wear out. With higher accuracy and no backlash, customers can produce more accurate products because their test system is now more accurate.

Applications

Applications for the ALAR include single and multi-axis electro-optic sensor testing, missile seeker testing, antenna testing, inertial navigation device testing, photonic component alignment, high-accuracy laser machining and precision wafer inspection. These include testing in vacuum to 10-6 torr. These rotary stages can also be configured as multi-axis gimbals.

High Speed

ALAR stages can operate between 45-300 rpm, depending on the particular model selected. This speed range is significantly higher than gear-drive stages of similar size.

Superior Mechanical Design

Angular contact bearings are used to maximize performance with respect to tilt error, moment stiffness and rotating friction. A precision-machined shaft further minimizes tilt error. The design incorporates integral connections that minimize cable issues. The ALAR works especially well in applications that require 360° continuous motion but have limited space. The stage is 65-160 mm tall and provides smooth motion without travel restrictions.

Brushless Direct-Drive

To maximize positioning performance, the ALAR series utilizes Aerotech’s brushless, slotless motors. 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 there is absolutely no torque ripple. This makes the ALAR ideal for applications requiring outstanding contoured motion, smooth scan velocity or precise incremental steps.

High Payload Capacity and Large Moment Load Stiffness

The ALAR comes in two different configurations. The standard profile (SP) unit has high payload capacity and high moment load stiffness so it can handle applications where its rotation axis is parallel or perpendicular to gravity and the payload center of gravity is cantilevered away from the stage. The low profile (LP) unit has high payload capacity and is good for applications where the axis of rotation is parallel to gravity. Both the SP and LP units have the same aperture options and motor options. Either SP or LP stages can handle between 260-1300 lb of axial load.

Accurate Positioning

Performance is assured with encoder line counts from 31000 to 76800 per rev, resulting in resolutions from 0.02 arc sec/count to 0.009 arc sec/count. The motor and high-performance rotary encoder are directly coupled to a common shaft. The absence of gear trains and mechanical couplings means no position errors caused by hysteresis, windup or backlash. As a result, accuracy of ±2 arc sec and bi-directional repeatability of ±0.5 arc sec is attainable.ALAR2

Flexible Configurations

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

Specifications

ALAR Series Specifications

ModelALAR-100-SP ALAR-100-LP ALAR-150-SP ALAR-150-LP
Aperture 100 mm 100 mm 150 mm 150 mm
Motor S-180-44-A Brushless Slotless S-240-43-A Brushless Slotless
Continuous Current Apk 2.7 A 5.76 A 6.2 A 5.41 A
Arms 1.9 A 4.1 A 4.4 A 4.1 A
Peak Current, Stall Apk 10.8 A 33.5 A 24.8 A 31.4 A
Arms 7.6 A 23.7 A 17.5 A 22.2 A
Bus Voltage Up to 340 VDC
Length 250 mm 250 mm 300 mm 300 mm
Width 250 mm 250 mm 300 mm 300 mm
Height 100 mm 65 mm 100 mm 65 mm
Unlimited Travel Yes
Maximum Limited Travel ±170° ±170° ±170° ±170°
Maximum Velocity @ 160 V Bus(1) 300 rpm 50 rpm 250 rpm 45 rpm
Maximum Acceleration 1364 rad/s2 1009 rad/s2 1330 rad/s2 829 rad/s2
Resolution(2) 0.1 µrad (0.02 arc sec) 0.1 µrad (0.02 arc sec) 0.08 µrad (0.016 arc sec) 0.09 µrad (0.018 arc sec)
Maximum Torque 23.9 N-m 11.9 N-m 42.9 N-m 15.4 N-m
Continuous Torque 6.0 N-m 2.0 N-m 10.7 N-m 2.6 N-m
Weight 160 N (36 lb) 81 N (18.1 lb) 182 N (41 lb) 96 N (21.6 lb)
Weight with Limits 167 N (37.5 lb) 87 N (19.6 lb) 192 N (43.2 lb) 106 N (23.8 lb)
Shaft Inertia 0.022 kg-m2 0.022 kg-m2 0.040 kg-m2 0.031 kg-m2
Shaft Inertia with Limits 0.026 kg-m2 0.026 kg-m2 0.051 kg-m2 0.042 kg-m2
Axial Load 1550 N (348 lb) 1175 N (264 lb) 1950 N (438 lb) 1325 N (298 lb)
Radial Load 1350 N (303 lb) 950 N (214 lb) 1925 N (433 lb) 1275 N (287 lb)
Moment Load 250 N-m 150(3) N-m 450 N-m 225(3) N-m
Repeatability ±2.4 µrad (±0.5 arc sec)
Accuracy(4) ±9.7 µrad (±2 arc sec)
Tilt-Error Motion 9.7 µrad (2.0 arc sec)
  1. Square-wave digital encoder options will limit maximum speed below the listed value. Contact factory for specific stage and encoder speed combination.
  2. Resolution assumes -AS encoder with 2000X controller multiplication.
  3. The ALAR-LP base must be fully supported by a rigid mounting plate to achieve this moment load.
  4. Certified with each stage. Requires the use of an Aerotech controller.

ALAR Series Specifications

ModelALAR-200-SP ALAR-200-LP ALAR-250-SP-2 ALAR-250-SP-3 ALAR-250-LP
Aperture 200 mm 200 mm 250 mm 250 mm 250 mm
Motor Brushless Slotless
Continuous Current Apk 5.3 5.3 5.3 7.95 5.3
Arms 3.75 3.75 3.75 5.62 3.75
Peak Current, Stall Apk 34.8 34.8 34.8 52.2 34.8
Arms 24.6 24.6 24.6 36.9 24.6
Bus Voltage Up to 340 VDC
Length 400 mm 400 mm 450 mm 450 mm 450 mm
Width 400 mm 400 mm 450 mm 450 mm 450 mm
Height 150 mm 100 mm 150 mm 150 mm 100 mm
Unlimited Travel Yes
Maximum Limited Travel ±170° ±170° ±170° ±170° ±170°
Maximum Velocity(1) 90 rpm 90 rpm 140 rpm 140 rpm 90 rpm
Maximum Acceleration 361 rad/s2 570 rad/s2 287 rad/s2 287 rad/s2 407 rad/s2
Resolution(2) 0.06 µrad
(0.012 arc sec)		 0.07 µrad
(0.014 arc sec)		 0.05 µrad
(0.01 arc sec)		 0.05 µrad
(0.01 arc sec)		 0.05 µrad
(0.01 arc sec)
Maximum Torque 86 N-m 86 N-m 92 N-m 138 N-m 92 N-m
Continuous Torque 12.9 N-m 12.9 N-m 14.1 N-m 21.1 N-m 14.1 N-m
Weight 396 N (89 lb) 277 N (62.3 lb) 503 N (113 lb) 503 N (113 lb) 343 N (77.1 lb)
Weight with Limits 423 N (95 lb) 295 N (66.4 lb) 534 N (120 lb) 534 N (120 lb) 367 N (82.6 lb)
Shaft Inertia 0.320 kg-m2 0.190 kg-m2 0.500 kg-m2 0.500 kg-m2 0.310 kg-m2
Shaft Inertia with Limits 0.359 kg-m2 0.229 kg-m2 0.573 kg-m2 0.573 kg-m2 0.383 kg-m2
Axial Load 4675 N (1051 lb) 4350 N (978 lb) 4950 N (1113 lb) 4950 N (1113 lb) 4950 N (1113 lb)
Radial Load 4775 N (1073 lb) 4125 N (927 lb) 5200 N (1169 lb) 5200 N (1169 lb) 5050 N (1135 lb)
Moment Load 1600 N-m 1075(3) N-m 1825 N-m 1825 N-m 1475(3) N-m
Repeatability ±2.4 µrad (±0.5 arc sec)
Accuracy(4) ±9.7 µrad (±2 arc sec)
Tilt-Error Motion 9.7 µrad (2.0 arc sec)
  1. Square-wave digital encoder options will limit maximum speed below the listed value. Contact factory for specific stage and encoder speed combination.
  2. Resolution assumes -AS encoder with 2000X controller multiplication.
  3. The ALAR-LP base must be fully supported by a rigid mounting plate to achieve this moment load.
  4. Certified with each stage. Requires the use of an Aerotech controller.

ALAR Series Specifications

ModelALAR-325-SP-2 ALAR-325-SP-3 ALAR-325-LP
Aperture 325 mm 325 mm 325 mm
Motor Brushless Slotless
Continuous Current Apk 5.1 7.65 5.1
Arms 3.63 5.41 3.63
Peak Current, Stall Apk 31.2 46.8 31.2
Arms 22.1 33.1 22.1
Bus Voltage Up to 340 VDC
Length 525 mm 525 mm 525 mm
Width 525 mm 525 mm 525 mm
Height 150 mm 150 mm 100 mm
Unlimited Travel Yes
Maximum Limited Travel ±170° ±170° ±170°
Maximum Velocity(1) 150 rpm 150 rpm 120 rpm
Maximum Acceleration 185 rad/s2 185 rad/s2 339 rad/s2
Resolution(2) 0.04 µrad (0.009 arc sec) 0.04 µrad (0.009 arc sec) 0.04 µrad (0.009 arc sec)
Maximum Torque 143 N-m (1265.7 lb-in) 214.9 N-m (1902.0 lb-in) 143 N-m (1265.7 lb-in)
Continuous Torque 23.4 N-m 35.1 N-m 23.4 N-m
Weight 600 N (135 lb) 600 N (135 lb) 436 N (98 lb)
Weight with Limits 636 N (143 lb) 636 N (143 lb) 489 N (110 lb)
Shaft Inertia 1.01 kg-m2 1.01 kg-m2 0.55 kg-m2
Shaft Inertia with Limits 1.2 kg-m2 1.2 kg-m2 0.675 kg-m2
Axial Load 5825 N (1310 lb) 5825 N (1310 lb) 5825 N (1310 lb)
Radial Load 6650 N (1495 lb) 6650 N (1495 lb) 6450 N (1450 lb)
Moment Load 2650 N-m 2650 N-m 2200(3) N-m
Repeatability ±2.4 µrad (±0.5 arc sec)
Accuracy(4) ±9.7 µrad (±2 arc sec)
Tilt-Error Motion 9.7 µrad (2.0 arc sec)
  1. Square-wave digital encoder options will limit maximum speed below the listed value. Contact factory for specific stage and encoder speed combination.
  2. Resolution assumes -AS encoder with 2000X controller multiplication.
  3. The ALAR-LP base must be fully supported by a rigid mounting plate to achieve this moment load.
  4. Certified with each stage. Requires the use of an Aerotech controller.

Dimensions

  • ALAR-100-SP
  • ALAR-100-LP
  • ALAR-150-SP
  • ALAR-150-LP
  • ALAR-200-SP
  • ALAR-200-LP
  • ALAR-250-SP
  • ALAR-250-LP
  • ALAR-325-SP
  • ALAR-325-LP

Ordering Information

ALAR Series Ordering Options (highlighted options available from Aerotech's Fast Delivery Service program)

OptionDescription
-100-LP 65 mm high direct-drive rotary stage with 100 mm clear aperture, dual precision bearings, 2.0 N-m continuous torque and 31488 line amplified sine encoder
-100-SP 100 mm high direct-drive rotary stage with 100 mm clear aperture, dual precision bearings, 5.9 N-m continuous torque and 31488 line amplified sine encoder
-150-LP 65 mm high direct-drive rotary stage with 150 mm clear aperture, dual precision bearings, 2.6 N-m continuous torque and 36000 line amplified sine encoder
-150-SP 100 mm high direct-drive rotary stage with 150 mm clear aperture, dual precision bearings, 10.7 N-m continuous torque and 40000 line amplified sine encoder
-200-LP 100 mm high direct-drive rotary stage with 200 mm clear aperture, dual precision bearings, 12.9 N-m continuous torque and 47200 line amplified sine encoder
-200-SP 150 mm high direct-drive rotary stage with 200 mm clear aperture, dual precision bearings, 12.9 N-m continuous torque and 55040 line amplified sine encoder
-250-LP 100 mm high direct-drive rotary stage with 250 mm clear aperture, dual precision bearings, 14.1 N-m continuous torque and 55040 line amplified sine encoder
-250-SP-2
 150 mm high direct-drive rotary stage with 250 mm clear aperture, dual precision bearings, 14.1 N-m continuous torque and 64800 line amplified sine encoder
-250-SP-3 150 mm high direct-drive rotary stage with 250 mm clear aperture, dual precision bearings, 21.1 N-m continuous torque and 64800 line amplified sine encoder
-325-LP 100 mm high direct-drive rotary stage with 325 mm clear aperture, dual precision bearings, 23.4 N-m continuous torque and 64800 line amplified sine encoder
-325-SP-2-LT 160 mm high direct-drive rotary stage with 325 mm clear aperture, dual precision bearings, 23.4 N-m continuous torque and 74612-line amplified sine encoder; typically used in applications where the axis of rotation is horizontal or vertical. NOTE: The 325-SP-2-LT is limited travel only. It must include the -LI limit option. Customer must provide hardstops appropriate for their application.
-325-SP-2-CT 160 mm high direct-drive rotary stage with 325 mm clear aperture, dual precision bearings, 23.4 N-m continuous torque and 76800-line amplified sine encoder; typically used in applications where the axis of rotation is horizontal or vertical. NOTE: The 325-SP-2-CT is unlimited travel. If LI limit option is required, customer must provide hardstops appropriate for their application.
-325-SP-3-LT 160 mm high direct-drive rotary stage with 325 mm clear aperture, dual precision bearings, 35.1 N-m continuous torque and 74612-line amplified sine encoder; typically used in applications where the axis of rotation is horizontal or vertical. NOTE: The 325-SP-3-LT is limited travel only. It must include the -LI limit option. Customer must provide hardstops appropriate for their application.
-325-SP-3-CT 160 mm high direct-drive rotary stage with 325 mm clear aperture, dual precision bearings, 35.1 N-m continuous torque and 76800-line amplified sine encoder; typically used in applications where the axis of rotation is horizontal or vertical. NOTE: The 325-SP-3-CT is unlimited travel. If LI limit option is required, customer must provide hardstops appropriate for their application.
  1. Note: -SP is for horizontal or vertical axis applications; -LP is for vertical axis applications.

Encoder Type

OptionDescription
-CT Continuous Travel Internal Encoder

Encoder Output Options

OptionDescription
-AS Standard feedback device; 1 Vpp sine wave output; multiply the selected stage resolution by the encoder multiplier to get final resolution of counts per rev
-X5 Square-wave digital output which includes a 5-times multiplier; multiply the selected stage encoder lines by 20 to get the final resolution of counts per rev*
-X10 Square-wave digital output which includes a 10-times multiplier; multiply the selected stage encoder lines by 40 to get the final resolution of counts per rev*
-X25 Square-wave digital output which includes a 25-times multiplier; multiply the selected stage encoder lines by 100 to get the final resolution of counts per rev*
-X50 Square-wave digital output which includes a 50-times multiplier; multiply the selected stage encoder lines by 200 to get the final resolution of counts per rev*
  1. Note: * indicates this includes controller quadrature; X5, X10, X25, X50 square-wave encoder options have limited bandwidth and may not reach stage max speed. Please contact factory to confirm speed per stage.

Limit Options

OptionDescription
-UNLIMITED No travel limits or hardstops; valid only with -CT encoder type
-LIx Normally-closed limits at x degrees total travel, where x = 10/20/30/60/90/120/180/240/300/340; integrated hardstops 5 degrees past LI limit switch angles; other travel angles available by special order; increases stage height by 10 mm; can be used with -CT or -LT encoder types; ALAR-250 and ALAR-325 hardstops are special order only; contact the factory for pricing