[simpits-tech] Control force methods

[Matt Bailey]

Just thought I'd share some observations on a couple of control systems I've 
used recently. The other day, I was flying a PFC setup at the flight school 
I'm attending. From the PFC webpage, it seems they used bungees for yoke 
resistance. I was noticing that with increasing back pressure, the feel 
actually is recognizably similar to applying back pressure in a small GA 
plane.

We also have a Frasca sim. I'm pretty sure it uses pneumatics for resistance 
(well, if not, they need to investigate that hissing noise behind the panel. 
:) It also has quite a good feel. I have thought for a while that pneumatics 
would be the way to go, but I would have fly the Frasca some more to decide 
if I liked it better than the PFC actually.

Anyway, both systems seem to be quite good. I hadn't really noticed it 
before, but the other day the bungee kinda surprised me at how realistic it 
felt.

The two items that really stood out as "not right" were:

1. Lack of pressure. Probably easy to solve on either system.

2. Both systems were too smooth. Maybe it's the roughness of slightly 
turbulent air going over the control surfaces, maybe it's the control 
rigging, probably both, but the controls in a real plane have a little more 
roughness to them. Light, high frequency vibrations I guess. With a pneumatic 
system, maybe this could be simulated by constantly circulating disturbed air 
in the cylinders? Or maybe even running low frequency sound waves through or 
around the cylinder, sorta make it into a subwoofer. Bungees would be a bit 
more limited, not sure how you would get the roughness.

Has anyone tried either system in their sim? I know Rod Dale is using a car 
shock for rudder pedals, what about other controls?

If only I had some extra money so I could start my sim and try this stuff out 
myself. :)

	-Matt Bailey