MI-8100 Family of Precision Two-Axis Gimbal Positioners


Incorporating direct drive motors and extremely accurate encoders, the MI-8100 Gimbals provide superb responsiveness and pointing accuracy. The MI-8120 Two-Axis Gimbal offers extreme accuracy by virtue of its direct drive motors that are structurally coupled to the encoders and the antenna/ counterweight system. Flexible couplings are absent, as are gears, timing belts and virtually all the conventional sources of positioning error in a mechanical drive. System stiffness is thereby greatly enhanced, and backlash is completely eliminated.

Accuracy is further enhanced by the use of high precision, angular contact bearings. Minimum friction and zero bearing clearance are achieved by tailoring the bearing selection and preload amount for specific applications.


The gimbal structure is precision engineered to assure that static deflection and dynamic properties are appropriate for each application, resulting in increased accuracy and extended servo bandwidth. The gimbal is capable of operating over a wide speed range, up to 45 degrees per second depending upon antenna size and weight. The direct drive configuration is free of the speed limitations inherent with conventional positioners. Extended travel, up to ±70 degrees, is available on both axes. A novel counter weighting configuration and a lowprofile trunion allow a remarkable range of motion.

  • Ideal for use in radome test systems
  • Direct-drive motors coupled to encoders
  • Backlash completely eliminated
  • High precision, angular contact bearings enhance accuracy
  • Wide speed range, up to 45 degrees per second
  • Extended travel up to ±70 degrees on both axes
  • Supports a wide assortment of antennas
  • Compact design easily fits inside small volumes
  • High structural stiffness allows extended servo bandwidth for demanding tracking applications


Parameter Units MI-8100
Typical deg 0.005
Achievable deg 0.0025
Antenna Size in (mm) Up to 42 in (1067 mm) typical, larger antennas are possible
Antenna Weight lbs (kgs) Up to 100 lbs (45 kg) typical, heavier antennas are possible
Axis Intersection in 0.005
mm 0.13
Peak Delivered Torque ft-lbs 2.3
Nm 3
Repeatability deg 0.001
Resolution deg 0.0001
Speed deg/s Up to 45 degrees/second, depending on antenna size and weight
Travel Limits deg Up to ±70 degrees in both axes


The MI-8100 Family of Precision Gimbal Positioners is ideally suited for high performance tracking applications. Virtually any suitable antenna can be smoothly driven at speeds ranging from imperceptible movement to a rapid slew.

The MI-8100 gimbal positioners can be customized to meet specific requirements.

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