Let’s MOVE!!

Finally a viable solution

It has taken a while to get here. Mostly because cost of a worthwhile motion platform has simply been out of reach of the ordinary person.

Finally, through HN Motion in Australia (link below), there is a 3DoF (4 actuator) solution with 150mm stroke and 350kg payload capacity, all at around €3000. For comparison, a similar setup can set you back double that amount easily from other popular suppliers.

Naturally we jumped at the chance!

3DoF vs. 6DoF rig

There are a number of reasons why 3DoF (roll/pitch/heave plus synthesised yaw and surge) is a better solution for our Spitfire simulator than 6DoF:

Cost, think around €10-20k for a rig with sufficient load bearing capacity AND stability;
Much more violent movement and impact on the cockpit frame
Height – you need a warehouse to run this in
Instability – you are swinging a massive weight through the air
Difficulty in modifying the cockpit such that the center of gravity and rotation runs through the pilots waist height.

In reality when flying what you experience most is heave roll in turbulent air and pitch changes when these are rapid. Normal manaeuvering rolls are done at neutral or low g-force (so actually a heave effect) It takes very little movement in VR to fool the brain into believing rather dramatic changes are happening.

Range of Motion

The range of movement is determined by the stroke of the actuators and their distance apart. Our movement will run as follows:

Pitch (9.3°): This is the Star of the Show.
In flight simulation, pitch is arguably more critical and frequently used than roll.
- Takeoff Rotation: The sensation of pulling back on the stick to lift off.
- Climb/Descent: The feeling of pointing the nose up or down.
- Flare: The critical rearward pitch for landing.
- Turbulence: Bumps and jolts are often translated into pitch movements.
  Having a strong 9.3° of pitch is a significant advantage for flight sim.
Roll (7.8°): Still Very Effective.
While slightly less than the pitch range, 7.8° is more than enough for effective cueing.
- Bank Initiation: The platform will give a solid “kick” to the side as you start a turn.
- Coordination: Combined with yaw and G-force effects from the sim, this tilt is highly effective at selling the turn.
- Wings-Level: The sensation of rolling back to level after a turn is very pronounced.

As you can see from the graphics above, the range of motion is significant.

Design

The initial design including mating surfaces and support frame has been done and will be a pretty simple conversion. I have the materials and the actuators on order so we should be able to do the assembly soon and will look forward to sharing our progress with you. Once we are happy with the way it is working we will be publishing the details in an update of our plan set.