RE: Skymaster F-15 Steering Stability
Thanks everyone for some great comments/suggestions. In exploring it some more I found and modified a couple things. First, I noticed that the subtle movements to the rudder did not change the position of the nose wheel. Even though I thought the pull-pull system was tight, there still was enough inherent slop that the servo horn would move but the nose wheel would not...it requires larger stick movement to get the nose wheel to move. Which I would think plays right into what RCDOUG was saying about Pilot induced oscillations. So I tightened the pull-pull system even more.
I also reduced the travel and increased the expo...especially on the low rate setting.
DELGATOGRANDE - As a former motorcycle (CBR1000RR) racer, you bring up a good point and I checked for play between the strut and retract. While there does not appear to be any play there the strut does have a slight side to side movement between the strut and the steering arm when operating the steering. I don't think this is enough to cause a counter steer effect however.
Those that mentioned Toe-in.... I understand toe-in and its stabilizing effects in the automotive world but wouldn't it be better to have a slight toe-OUT in this case?
I am thinking that as the plane starts to lean over and drag a wing tip, a toe-in condition would further assist this by trying to further steer into the turn rather than out. If the wheel was set to a toe-out setting when it came up on one side, the wheel still on the ground would try to force the plane out of the lean rather than into it.
I'll try it out tomorrow and let you know.
Regards,
Mike