Stewart platform guide

A Stewart platform (also called a hexapod) holds a moving top plate on six variable-length actuators arranged in a triangle pattern between the base and the plate. Lengthen or shorten the six actuators in coordinated patterns and the plate can move in all six degrees of freedom: three translations (surge, sway, heave) and three rotations (roll, pitch, yaw). No other compact mechanism gives a payload true six-axis motion, which is why the racing and driving simulator platforms in this catalogue are published on Stewart bases. The flight simulator platforms are published as six-degree-of-freedom motion — electric hydraulic on one model, electric servo on another — without the base mechanism being named; confirm the mechanism form for the flight model you are scoping instead of assuming a hexapod.

Reading a Stewart platform specification

• Load — the payload the plate carries while moving, not parked. In this line: from 200 kg class platforms to the YT-6DOF-Pro at 2,000 kg, with customisation cited to 5 tonnes.
• Accuracy and repeatability — how precisely the plate reaches and repeats a pose: +/-0.02 mm repeatability on the YT-6DOF, +/-0.008 mm on the Pro.
• Response and frequency — the published figures are per model and name different metrics: response time of 10 ms or better on the racing and driving bases, response delay of 15 ms or better on the marine and tank bases, and dynamic response delay under 5 ms on the rotational platform. The motion frequency band (0–5 Hz standard, 0–12 Hz Pro) decides how sharp a cue can feel.
• Drive type — servo electric cylinders for precision, cleanliness and accuracy (the racing platform publishes +/-0.1 mm positioning and no oil contamination risk); hydraulics for the heaviest loads and accelerations (the tank trainer runs +/-2G on a hydraulic base).
• Interface — EtherCAT/Modbus on the standard YT-6DOF; custom industrial protocols on the Pro. Your simulator software must speak to the base in real time.

Where the geometry earns its keep

Because all six actuators share every load, a Stewart platform is stiff and compact for its envelope — a 1.5 kW racing rig fits in 2.5 sqm. Its workspace is limited compared with serial robot arms, but simulators do not need a large workspace; they need believable accelerations inside a small one. If your task needs only heave, pitch and roll, the 3-DOF vs 6-DOF comparison may save you half the hardware budget.