[simpits-tech] May the Force Feedback be with you...

[Matt Bailey]

If you *really* want to do it right, I'd think you'd need a force and moment 
from the control surface. But I don't know of any flight sim that actually 
calculates this. You might be able to arrive at a reasonable guestimate with 
something like X-Plane that handles each airfoil seperately, and divides an 
airfoil into up to 10 sections. There are at least two ways you might go 
about this: by using airfoil speed, AoA, control surface span/chord/travel, 
you could perhaps calculate control surface pressure reasonably.

A cleaner method (although still requiring a fair amount of "extra" data 
input by the designer as part of the force feedback control software) would 
be to simply use airfoil lift. Seems like this might be a little easier and 
smoother.

	-Matt Bailey

On Sunday 09 February 2003 17:02, you wrote:
> I think that Marv said it well in his last email.
>
> The simplest design (using air) is a single spring loaded piston driven by
> a proportioning valve (servo regulator).  The valve can deliver whatever
> pressure you calculate from the sim's outputs.  The resultant force can be
> a function of velocity, stick position, trim wheel position, whatever data
> you want to use.
>
> Guessing here: IAS, AOA, and stick position would provide most of the data
> necessary to calculate the force from the stick.  I don't know how you'd
> determine turbulence, but the pneumatics are capable of some relatively
> high frequency output.
>
> Craig R.