cycraft

http://www.youtube.com/watch?v=D4qtxMPbfUk
What do you think about this construction, this type of simulator?
sensations are well?

you think it is interesting to build a simulator of this type (DIY)

the center of rotation is above the head, it 's better for good sensations.
there is no parasite force

There is a more pro version of this simulator here,

http://www.simuline.com/product/pro_cycraft.htm

I feel these simulators are actually capable of far more accurate motions than the frex or joyrider models. The overhead drive system more precisely conforms to the sensors within our auditory and vestibular pathways. This method actually moves all parts of the body in unison to the forces applied. The vertical motions exhibited are because this sim is 3DOF, and has a vertical component just like the FD301/401. It definitely appears stout enough in construction. If it does not move accurately to the video, in my assessment, that is probably due to the software which is arcade like.

Building a DIY version would require very strong structure, motors and electronic drive modules... $$$. But it could be a very accurate method of simulation.

Here is a good explanation of this concept they call parasitic
http://www.simuline.com/library/tech.htm

R-eng

The inner ear controls our sense of angle inclination.

Imagine our equilibrium organ in a simplified manner (as a ball in a tube):
___________________
|________0_________|
left------middle------right

Common simulators with pivot beneath the body do accellerate the head (with equilibrium organ) in the wrong direction.

Placing the pivot above the head keeps the head to rest in position, and the equilibrium organ does not send false body position signals to our brain.

I agree that this way is a superior method of simulating g-forces.

But it is no option for DIY, I guess, as the motor power requirements are very high.

regards

Well said Egoexpress.

@ Rayrace,

Well, what I experienced as a child, and even today, is that my head is connected to my body with a flexible neck. When a rapid movement change happens on my body, my head wants to continue in the direction before the change, because of its mass. Lucky I have a neck to keep it with my body then! :happy:

Your legs will feel the pressure from the surrounding structure and seat as they press against it during motion changes. They too will be flexible to move if not held in place. When you lay in bed motionless, what do you feel? Gravity via the pressure exerted on your body by the bed. The bed pushes against you as much as you push against the bed...laws of physics.

Even a tiny change in the position of the head can be sensed very clearly, both by the vestibular pathways and the nerves in the neck and other involved muscles.

R-eng

As I once posted about this subject, as long as the same cause and effect is repeatable on a consistent basis, the mind will adjust to it and consider it valid. That does not make it accurate though!

When you brake in a car, the head will move forward (relative to the rest of the body) both initially and during the deceleration. This is the negative longitudinal 'G forces. In a bottom pivot simulator, you are pitched forward so that the initial motion (the surge DOF) is for the head to remain stationary (or move backwards relative to the rest of the body), just as you would find in accelerating a car. After the sim moves to its rest brake position (ie. pitched forward), the force of gravity will impart it's effect just as if you were braking a real car.

In a top pivot sim during braking, it will move backwards both initially and while it assumes the final rest brake position. There are no opposing forces as in the previous bottom pivot model.

Both can be valid if the sim consistently applies these motions to the forces. The mind will adapt and correlate it as what is expected during such motions. Only one is accurate...the top pivot model, or any other that would apply initial and continuous motion in the same direction.

R-eng