Which motion platform is right for my build?

As a Product Manager at RobotDigg, I’ve seen the sim-racing and flight-sim industries evolve rapidly. One of the most common questions our engineering team receives is: "Which motion platform is right for my build?"
While both systems aim to provide immersion, the mechanical requirements for simulating a Boeing 737 are worlds apart from a GT3 race car. Based on the hardware we provide—from linear actuators to high-torque planetary gearboxes—here is an analysis of why the Stewart Platform reigns supreme for flight, while Open-Architecture Multi-Axis systems are the gold standard for racing.

1. The Stewart Platform (6-DOF): Precision and Pitch for Flight

The Stewart Platform, or hexapod, utilizes six linear actuators arranged in three pairs connecting a base to a top platform.
Why it’s the Flight Simulator Choice:
Large Range of Pitch and Roll: Pilots need to experience sustained climbs, descents, and steep banks. The Stewart platform excels at tilting the entire cockpit to simulate G-forces through "gravity vectoring."
Structural Integrity: Flight cockpits are often heavy, containing full yokes, overhead panels, and rudder pedals. The hexapod design distributes this weight evenly across six points of contact.
Complex Flight Dynamics: In flight, you deal with heave (vertical movement), surge, and sway simultaneously during turbulence or landing. The 6-DOF (Degrees of Freedom) mathematical model of a Stewart platform handles these synchronized movements with extreme mathematical precision.

2. The 5/6/7-Axis Open Simulator: The Race Simulation Specialist

In the second image, you see what we refer to as an "Open-Axis" or "Actuator-per-Corner" system. Unlike the Stewart platform, these actuators are often mounted directly to the corners of the rig or used to pivot specific sections (like a seat-mover or traction loss frame).
Why it’s the Race Simulator Choice:
High-Frequency Response: Racing is about "road feel"—vibrations from rumble strips, gear shifts, and tire scrub. Open simulators using RobotDigg’s high-speed servo actuators provide much faster "tactile" feedback than a heavy hexapod.
Traction Loss (The 7th Axis): One of the most critical sensations in racing is "oversteer." Open rigs easily allow for a dedicated "Traction Loss" frame that slides the rear of the rig left and right. This is difficult and mechanically "mushy" to replicate on a standard Stewart platform.
Surge and Sway Focus: In a car, you feel immediate longitudinal G-force when braking. Open systems often use dedicated surge rails to slide the entire cockpit forward and back, providing a sharper, more visceral sensation of braking and acceleration.

Which one should you build?
Choose a Stewart Platform (Hexapod) if:
You are building a commercial flight training rig.
You prioritize smooth, large-scale tilts (Pitch/Roll).
You have a heavy, enclosed cockpit.

Choose a 5/6/7-Axis Open System if:
You are a competitive sim-racer (iRacing, Assetto Corsa, Simtools).
You need to feel the "snap" of a car losing grip (Traction Loss).
You want a modular system that you can upgrade over time (starting with 3-DOF and adding more later).

The RobotDigg Advantage
Whether you are building a hexapod or an open-axis rig, the heart of the system is the Actuator. RobotDigg provides the specialized hardware required for both:
For Stewart Platforms: High-load Linear Actuators with precision ball screws.
For Race Rigs: High-speed Servo Motors and specialized U-joints to handle the violent vibrations of the track.