A turntable is the single most load-bearing instrument in an inertial navigation or seeker development lab: it produces the rotation inputs that calibrate gyros, validate INS algorithms and excite seeker control loops. But the catalog spans single-axis rate tables, three-axis motion simulators and custom far-field antenna positioners, and choosing the wrong class wastes both test throughput and budget. This guide maps published specifications of three representative machines to the programs they fit.
Single-Axis Rate Tables: Calibration Workhorses
For gyro and accelerometer calibration — position, rate and rocking tests — a single-axis table is usually enough. The DZT1-40 single-axis rate table is a platform-type multi-function test turntable driven by an industrial control computer with direct-drive torque motors and inductosyn or grating angle feedback:
- Load capacity 50 kg with table top runout of 0.015 mm
- Tilt rotation error 2″; angular position accuracy ±1″, resolution 0.36″, repeatability ±1″
- Rate range 0.001°/s to 1500°/s — wide enough for MEMS through tactical-grade FOG testing
- Rate accuracy and stability 1×10⁻³ (1° average), 1×10⁻⁴ (10° average), 1×10⁻⁵ (360° average)
- Maximum angular acceleration 500°/s²; position, rate and rocking modes
- User-defined slip rings for power and signals to the rotating unit under test
Three-Axis Motion Simulators: When One Axis Is Not Enough
Full six-profile INS testing, seeker line-of-sight emulation and multi-axis sensor fusion validation need three independent axes. The DZT3-120 three-axis rate table uses a U-U-T / U-O-O structure with unlimited continuous rotation on all three axes:
- Load capacity 120 kg, load dimensions Φ700 × 700 mm, body weight 1600 kg
- Tilt rotation error ±3″, axis perpendicularity ±3″, axes intersecting within a Φ0.3 mm sphere
- Angular position accuracy ±2″, control accuracy ±1″, repeatability ±1″, resolution 0.36″
- Rate range ±0.001°/s to 100°/s per axis with 0.0001°/s rate resolution
- Maximum acceleration 100°/s² on all three axes; axis locks at 0°, 90° and 180°
- Typical loads from 30 kg to 120 kg for avionics boxes, IMU clusters and EO payloads
Axes that intersect within 0.3 mm matter more than brochure headline accuracy: it is what keeps coning error out of your data when all three axes run simultaneously.
Far-Field Antenna and Radar Positioners
Radar seekers, datalink antennas and electro-optical payloads under test in anechoic or far-field ranges need load capacity and integrated services instead of raw rate. The DZT3-1500 far-field antenna test turntable carries up to 1500 kg with inner and outer axes rotating continuously and a middle axis pitching −70° to +50°:
- Angular position accuracy ≤ ±1′ and repeatability ≤ ±0.5′ on all axes; resolution 30″
- Rate range 1–10°/s inner, 1–5°/s middle and outer; acceleration up to 4°/s²
- Integrated photoelectric-hydraulic slip rings: power, signal, optical fiber and coolant (DN40)
- 100 Hz synchronous recording via TTL signal, 50% duty cycle, for time-aligned measurement capture
- Absolute and relative zero positioning on all three axes
The Spec Checklist Before You RFQ
- Load and CG: state the maximum payload mass, envelope and center-of-gravity offset — axis bearing sizing and slip-ring count follow from it.
- Rate range versus your gyro: the table’s minimum rate should be an order below the gyro’s bias stability floor; 0.001°/s covers most MEMS and tactical FOG work.
- Rate stability is interval-dependent: always ask which averaging window the 1×10⁻⁵ figure assumes (here: 360° average).
- Resolution and accuracy are different numbers: 0.36″ resolution does not guarantee ±1″ positioning — check both plus repeatability.
- Through-rotation services: count power channels, signal types, optical fiber rotary joints and coolant rings early; retrofitting slip rings is the costliest change order.
- Modes: position, rate, rocking and servo/simulation modes cover the full test matrix; confirm your profile replay format is supported.
Frequently Asked Questions
Can one turntable serve both IMU calibration and seeker testing?
Partially. A three-axis simulator such as the DZT3-120 covers IMU profiles and seeker line-of-sight dynamics; far-field antenna measurements with heavy payloads and cooling need a positioner class like the DZT3-1500.
Why does rate stability improve with longer averaging?
Short-term encoder and drive noise averages out over larger angle intervals, which is why the same machine quotes 1×10⁻³ at a 1° average but 1×10⁻⁵ over 360°. Compare vendors at the same window.
What accuracy do I need for MEMS IMU calibration?
MEMS bias floors are typically far above arcsecond-level table error, so ±1″ positioning with 0.001°/s minimum rate is comfortably sufficient; spend the budget on rate stability instead.
How are seekers exercised on a rate table?
The simulator replays line-of-sight angle profiles captured from flight or engagement simulation while the seeker outputs are recorded — the same hardware that strapdown and platform image seekers are validated on before flight test.
Request a Turntable Configuration
All specifications above are transcribed from current manufacturer datasheets. Send us your payload mass, envelope, required rate range and through-rotation services, and our engineers will configure the closest standard table or a customized variant — including slip-ring and control-room integration — within one working day. Contact INT for turntable sizing and RFQ pricing.