hi spad,
you can get everything you need to know from the default 737 cfg file,as follows
//0 Class <0=none,1=wheel, 2=scrape, 3=float>
//1 Longitudinal Position (feet)
//2 Lateral Position (feet)
//3 Vertical Position (feet)
//4 Impact Damage Threshold (Feet Per Minute)
//5 Brake Map (0=None, 1=Left, 2=Right)
//6 Wheel Radius (feet)
//7 Steer Angle (degrees)
//8 Static Compression (feet) (0 if rigid)
//9 Max/Static Compression Ratio
//10 Damping Ratio (0=Undamped, 1=Critically Damped)
//11 Extension Time (seconds)
//12 Retraction Time (seconds)
//13 Sound Type
//14 Airspeed limit for retraction (KIAS)
//15 Airspeed that gear gets damage at (KIAS)
[contact_points]
point.0=1, 40.00, 0.00, -8.40, 1181.1, 0, 1.442, 55.92, 0.6, 2.5, 0.9, 4.0, 4.0, 0, 220.0, 250.0
point.1=1, -7.75, -8.58, -8.60, 1574.8, 1, 1.442, 0.00, 1.0, 2.5, 0.9, 6.9, 6.9, 2, 220.0, 250.0
point.2=1, -7.75, 8.58, -8.60, 1574.8, 2, 1.442, 0.00, 1.0, 2.5, 0.9, 7.1, 7.1, 3, 220.0, 250.0
point.3=2, -14.17, -47.33, 0.00, 787.4, 0, 0.000, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 5, 0.0, 0.0
point.4=2, -14.17, 47.33, 0.00, 787.4, 0, 0.000, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 6, 0.0, 0.0
point.5=2, -54.00, 0.00, 2.83, 787.4, 0, 0.000, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 9, 0.0, 0.0
point.6=2, 42.67, 0.00, -3.75, 787.4, 0, 0.000, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 4, 0.0, 0.0
Points 0, 1 and 2 are class 1, which is a wheel.
Just count carefully from the = sign
Point 0 which is always(?) the nose or tail wheel is +40 ft from the model reference point and 0 feet off the centre line. The point of contact with the ground is 8.4 ft below (-) the line through the reference point longitudinally through the fuselage. If the wheel is stuck in the ground, increase the number a bit. If it in the air above the ground, reduce it.
Count along and work out the rest for yourself. One of the important ones is steering angle. Many tail draggers have this set at 180 degrees (because the designer wants the wheel to caster). That doesn't work - the FS model can't cope with it despite what a lot of people think. It just makes the plane impossible to steer on the ground. Making it something like 70/80 degrees gives you proper control.
Messing around with things like damper compression is more of an art than a sciemce in my own experience. From the number of aircraft that jump about while they are static on the ground, I'm not the only one either
All of this stuff is in the aircraft SDK as well, but I don't think that tells you a lot more than the above really. As usual, the best way to learn is to back up your file then change the numbers, play and see what happens.
Have fun!
PS
One more thing - when turning on the ground, a major factor that influences the diameter of the turning circle and the rate of turn is the empty_weight_yaw_MOI (especially for AI aircraft). For the default 737:
empty_weight_yaw_MOI = 3337024
As a general rule, the bigger the number, the bigger the diameter and the slower the aircraft turns and vice versa
Thanks from mike (spad0007)
