MI-840 Family of RCS Rotators

MI-840

The MI-840 Family of RCS Rotators are typically used in a compact range or far-field measurement system to measure the radar signature of a device (target). These rotators sit atop a variety of RCS pylons and create a positioning system that combines high weight bearing, accurate positioning and low RF reflectivity. This positioning system is synchronized with the RF instrumentation to provide the RCS measurement data. Data analysis of the range measurements using the MI-3048 RCS Analysis Software completes the radar cross-section measurement results.

Azimuth-over-elevation rotators provide low profile positioning for 500 lbs (227 kg), 1,500 lbs (682 kg), 3,000 lbs (1,364 kg), 8,000 lbs (3,629 kg), 15,000 lbs (6,820 kg), 20,000 lbs (9,072 kg), 30,000 lbs (13,640 kg) and 50,000 lbs capacities. These rotators are designed to meet high strength and accuracy requirements within a minimal package to aid model design and testing.

downloadpdfAll structural elements are highly engineered to safely resist all the stresses placed upon them in all foreseeable loading scenarios. Primary structural elements are subjected to classical stress analysis and finite element analysis. Minimum safety factor is 2.5, based on yield, for all structural components.

The elevation drive train uses a self-locking mechanism to provide protection against axis movement in the event of a motor or belt failure. The azimuth drive utilizes a high efficiency drive with dual, fail-safe holding brakes.

Environmental protection is paramount. Although not sealed (a near impossibility), the rotator is completely shielded from windblown rain when it is at 0° elevation angle. Likewise, windblown sand cannot enter the rotator from the top or sides, but only from the bottom, through a minimally-sized opening required for the intrusion of the primary structure. Both internal and external components are fabricated for corrosion protection.

MI-840 Uncovered

Both axes incorporate syncho feedback. Synchros have proven reliable for many years in the field, even in shielded outdoor environments. Their accuracy is absolute (rather than incremental), a quality that makes them very appealing in a slow-moving rotator. They do not have to be “homed” prior to each use as with incremental position feedback systems.

  • Low profile positioning
  • Accurate azimuth and elevation axis
  • Load capacity up to 30,000 lbs
  • Interchangeable tip design matches rotator needs with MI pylons

Specifications

MI Rotators MI-840-0.5K MI-840-1.5K MI-840-3.0K MI-840-8.0K MI-840-15K MI-840-20K MI-840-30K MI-840-50K
Target Weight 500 lbs
(227 kg)
1,500 lbs
(682 kg)
3,000 lbs
(1,364 kg)
8,000 lbs
(3,629 kg)
15,000 lbs
(6,820 kg)
20,000 lbs
(9,072 kg)
30,000 lbs
(13,640 kg)
 
EL Delivered Torque 500 ft-lbs
(678 Nm)
1,500 ft-lbs
(2,034 Nm)
3,600 ft-lbs
(4,881 Nm)
10,000 ft-lbs
(13558 Nm)
19,500 ft-lbs
(26438 Nm)
50,000 ft-lbs
(67791 Nm)
65,250 ft-lbs
(88467 Nm)
 
AZ Delivered Torque 200 ft-lbs
(271 Nm)
350 ft-lbs
(474 Nm)
720 ft-lbs
(976 Nm)
2,000 ft-lbs
(2,711 Nm)
5,000 ft-lbs
(6,779 Nm)
10,000 ft-lbs
(13,558 Nm)
20,833 ft-lbs
(28,246 Nm)
 
Elevation Travel -45°, +5° -45°, +5° -45°, +5° -45°, +5° -33°, +5° -33°, +5° -33°, +5°  
Azimuth Travel 360°, Continuous
Accuracy, Elevation (Synchro) ±0.05° ±0.05° ±0.05° ±0.15° ±0.15° ±0.10° ±0.10°  
Accuracy, Azimuth (Synchro) ±0.05°
Rotation Speed, Azimuth 42 deg/min 36 deg/min 48 deg/min 60 deg/min 60 deg/min 60 deg/min 60 deg/min  
Rotation Speed, Elevation 6.5 deg/min 4.2 deg/min 7.5 deg/min 6 deg/min 6 deg/min 6 deg/min 6 deg/min  
Dimensions
Diameter 10 in
(25 cm)
15 in
(38 cm)
19 in
(48 cm)
22 in
(56 cm)
22 in
(56 cm)
40 in
(101 cm)
40 in
(101 cm)
 
Height 5 in
(13 cm)
6 in
(15 cm)
7.5 in
(19 cm)
12 in
(30 cm)
12 in
(30 cm)
15 in
(38 cm)
20 in
(51 cm)
 

Related Products

  • MI-710C Position Control System
  • MI-830 Family of Pylons
  • MI-500 Family of Compact Range Reflectors
  • MI-3048 RCS Analysis Software
  • MI-350 Advanced Microwave Measurement System