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Guest Rosin

How to adjust rotten FS ground steering?

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hi dear people,can anyone give me a hint about which part of the .cfg file of an aircraft i have to change in terms to affect the way rudder pedals (ground steering) act?as a default, FS has a very unrealistic ground steering dynamics: you press slightly the pedal and the plain responds very late and heavily as if the wires/levers are being made out of rubber. I practically find it impossible to take off without making some strange kinds of zig-zags on the runway. i even start to develope a "skill" for this kind of steering--anticipating and pressing in advance, etc. it is not issue of sensetivity--i've seen some guys design cars for FS where this issue is completely absent: you press the pedal and the response is immediate and light. so it's a configuring problem. i can't understand why FS makers never addressed this issue.thank you for your attention!***

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Just lettin you know that if you make the main gear farther apart, the planes steering is tightened, so it stands to reason that if you move them closer together, the planes steering would be less effective.. (editable in the .cfg file) Not sure if you want to do this though, because it might mess up the location of your touchdown effects...Tyler

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Play with these values in the aircraft.cfg file.(from the FS2004 DC-3 aircraft.cfg file)[brakes]parking_brake = 1 //Parking brake availabletoe_brakes_scale = 0.3 //Brake scalardifferential_braking_scale = 1.0 //Delta on the amount of brake when the rudder pedals deflectedLou

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> if you make the main gear farther apart, the planes steering is> tightened...I'm having the same kind of steering issue with a trike gear on avery light, very small plane. The steering angle of the centernose gear wheel is set to 40 degrees and the animation reflects thisjust fine, however, the angle doesn't seem to affect the actual TURNRADIUS and the wheel will be skidding along the ground even at verylow taxi speeds.> Not sure if you want to do this though, because it might mess> up the location of your touchdown effects...Exactly. Gear CPs are pretty much set in concrete for me. Main gearare 4.5 ft apart with the nose gear 3.5 ft in front of them. Pilotsits almost directly on the main gear axle just a few inches aft of CG.Length of plane is 17' prop to TE of rudder. Wingspan 28 ft and 4'above ground.

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thanks for the input Tyler, Lou and Scot!I'll try the things you sugest.Meanwhile i found a way of more clearly and shortly explaining what my problem (with all aircraft's) steering is:in a real plane, if i pres quickly the rudder pedals--L-R-L-R-L-R, all this for the laps of one second, the plane reacts immediately and makes instant small deviations L-R-L-R-L-R.In FS, if i press my rudder pedals several times so quickly, the animation reacts but the plain doesn't steer up until the end of the first second. As if i was pulling elastic rubber bands: you know when you pull something attached to the end of elastic rubber band nothing happens if you pull back and forth very quickly--in terms to affect the attached object you need to pull v e e r y slowly the rubber. hope it makes sense :) ***

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>thanks for the input Tyler, Lou and Scot!>I'll try the things you sugest.>>in a real plane, if i pres quickly the rudder>pedals--L-R-L-R-L-R, all this for the laps of one second, the>plane reacts immediately and makes instant small deviations>L-R-L-R-L-R.>In FS, if i press my rudder pedals several times so quickly,>the animation reacts but the plain doesn't steer up until the>end of the first second. As if i was pulling elastic rubber>bands: ... There is a relatively undocumented setting that can be placed in aircraft.cfg to change the 'aircraft steering rate'. That suggests the default steering has a delay. * Leave it to MS to do things behind our backs. * I don't remember the exact nomenclature, but have seen that line occasionally in aircraft.cfg files. Maybe someone will post it so you can check to see if setting a 'fast rate' helps you. MS may set the rate based on the weight, etc. of an AC. Or, perhaps there is a single default. Also note that steering too far will caues the nose wheel to lose traction and skid. A more forward CG should reduce that (mainly to test the effect). But, don't forget the rudder 'Sensitivity' setting in the Controls Menu might will slow down the steering if it's set 'low'. All 'high'sensitivity does is reduce the delay before the controls move. Which is not present in small AC with directly linked control surfaces.--------------- I think Scott was having a problem with the NG skidding. That is probably because the AC isn't set correctly for Newton's Laws of Motion. Many large AC are set with very excessive moments of inertia. One I tried steered on the ground like a big ship. It would be Yaw MoI that affects ground steering. However, if the location of the current CG, MG, and NG isn't correct, the weight on the NG might be too low to avoid skidding. Typically, only 5% of the total weight of a big jet is on the NG, so an excessive NG deflection for the current speed or excessive MoI's might be more likely. TO/Landing steering is limited to +/- 5 deg in real jets. MS Airheads lost the 'prop effect on tail' in FS9, so you don't get any low speed steering from the Prop Blast. This appeared to damage the C172SP even though it has tricyle gear. I guess it just shows that prop blast is important in light SEL AC in low speed steering. I know I'd give the tail a blast of prop to steer into a parking spot in a real PA 28 I flew long ago. It didn't have differential steering, just one brake lever.Ron

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> MS Airheads lost the 'prop effect on tail' in FS9, so you> don't get any low speed steering from the Prop Blast.Bummer! What's REALLY interesting about my UL we've been hashing over lately is that I have the CG set just like real (was always like that in the configs, just that miss-moded contact point causing all the grief before) and just like real I can get the plane to tip on it's tail skid with enough air flowing over the elev/stab and then STAY there! So cool. Give the engine a quick gun and she'll fall back on her nose wheel. I'm a happy camper. heheI'll play with setting CG a little more forward and see what happens with added "weight" on the NG. She does fly a little nose up at cruise (just like the real thing), so moving it a few inches foreward might help that as well.In reality, there's 120 pounds on each main gear and 60 on the NG when empty. With 160 lbs pilot, there's 220 each MW and 70 on the NG.Would be neat if FS calculated CP weights and you could see that data thru AFSD or something.

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>MS Airheads lost the 'prop effect on tail' in FS9, so you don't get any low speed steering from the Prop Blast. This appeared to damage the C172SP even though it has tricyle gear.

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> increase the Cn_dt Yaw Moment-Thrust entry to> 0.009. That change makes your Weedhopper turn pretty> well for me.0.03 works well for me. To bad that couldn't be scaled for reduced effect in flight... or can it?Thanks again for this nice piece of info!

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>>MS Airheads lost the 'prop effect on tail' in FS9, so you>don't get any low speed steering from the Prop Blast. This>appeared to damage the C172SP even though it has tricyle gear.>Ron,>>I'm confused, is the lost prop effect on rudder you mention>related to the Cn_dt Yaw Moment-Thrust airfile entry? Because>for aircraft with a low yaw MOI I'm seeing the same results>from editing that entry in FS9 as I did in FS2002 and CFS2. The effect is mainly apparent at low speeds. Where the prop increases the 'relative wind' significantly. I know AIR files set with both the Yaw and Pitch vs Thrust parameters had the expected effects in CFS2, lost the Pitch (elevator) effect in FS2K2, then also the Yaw (rudder) effect in FS9. I even tried setting the same parameters in an AIR file with the new records and saw no effect.>Try editing the Cn_dt Yaw Moment-Thrust entry in an aircraft>with a low yaw MOI setting such as the FS9 MS C-172. Increase>the value from the default 0.0 to a value of +1.0. Now start>FS9, select the C-172 and the default flight. With the parking>brake set and the rudder fully deflected either left or right,>increase the power and watch the aircraft spin like a top.>Setting it negative causes control reversal. OK, I'll see if a much larger value has an effect. Though, that would screw up the rudder effect in FS2K2. I think those values are set in many of my AIR files, even though they appeared to have no effect in FS9. For example, my same 'fixed' C208 will turn on the water with a prop blast on the rudder in FS2K2, but not in FS9. I'm working on an AIR file with MoI's only around 300 sl-ft^2 now and fly it in both FS2K2 and 2K4. There are also two similar parameters usually set to -5.0 and -10.0. It was found they increase Yaw and Roll Damping with a prop blast. I don't know if they still have an effect or not -- I haven't seen anything obvious. I have also added lines relating to everything I'm aware of with the scalar's set to 1.0. Normally, 1.0 is the default if such lines are missing in aircraft.cfg. So, they should be needed only if one wants the effect larger or smaller than normal. Since I set everthing possible in the AIR file my 'scalars' are normally 1.00. But, one never knows what these lines do until one verifies them. Some, such as [autopilot] "max pitch=xx" have no effect. Even lines that 'work' are explained so poorly so we have to verify that they do what they should. Some only scale AIR file parameters, which isn't much value if they are zero in the AIR file. >Regarding the prop effect on elevator, I've noticed during my>quest for raising the tail on the DC-3 at a lower airspeed>that Cm_dt Pitch Moment-Thrust does have an effect in FS9 but>it does not seem related to either power/thrust changes or>prop wash. In its present state this entry will only act to>change the aircraft

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>0.03 works well for me. To bad that couldn't be scaled for reduced effect in flight... or can it?OK, I'll see if a much larger value has an effect. Though, that would screw up the rudder effect in FS2K2.There are also two similar parameters usually set to -5.0 and -10.0. It was found they increase Yaw and Roll Damping with a prop blast. I don't know if they still have an effect or not -- I haven't seen anything obvious.Hmm. Actually, I tried setting those lines in an FS2K2 twin and they didn't have a logical effect. However, the props are not in line with the tail, so the effect would be lower than normal. Further, it would have to account for differences in power settings to be done correctly.Seems a good part of doing more realistic FM's is fixing what MS broke or left out.

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>Ron,>>The value of +1.0 for Cn_dt is too high for the flight>dynamics. If I recall correctly, the C-172 will spin just as>readily in the air with rudder deflection if Cn_dt is set that>high. I set it to about 0.0065 for better steering and no>effect on the flight behavior.> I see the MS Extra 300 is set to Cn_dT = 0.01. All the other three are 0.0>>There are also two similar parameters usually set to -5.0 and>-10.0. It was found they increase Yaw and Roll Damping with a>prop blast. I don't know if they still have an effect or not>-- I haven't seen anything obvious.<>>>Cn_r(T) Yaw Damping-Thrust is usually set to -5.0, it does>work, and if you set Cn_r low enough you can see the effect.>But it can cause the aircraft to slip during a level turn,>making a constant rudder input necessary to keep the ball in>the center, unless you set CY_r high enough. OH, OH. Maybe that's the problem with most of my SEL's!>The only thing I can recall seeing set to -10 is the Cm_q(T)>Pitch Damping-Thrust parameter. It seems to affect the>pitch/power couple more than anything else, although at higher>negative numbers it will definitely damp the aircraft's>pitching moment. And at a high positive number (+100 or more)>the aircraft will tumble end over end. I'm setting this to>about +1.0 now, because I find that a small positive number>allows for a better pitch response to power changes. Often pitch changes too much with power. But, it's hard to know how a specific AC is without having flown it recently. Ron

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hi Ron! it must be some default MS "steering value" as you put it. you use the corect word to name the problem: delay. large aicrafts would be expected to have inertia and a feel of drift and heaviness that may result in some similar delay but this would happen only if they taxi with some higher speed and sharp angle of the steering wheel.by the way, i became aware and slightly irritated (hehe) with the microsoft's default steering delay for two reasons-one: when accompanying someone ina flight i felt the feeling of the steering response of a small french plane (cessna's size) while taxiing-there was no delay. then also, i started to fly this amazing sim Falcon4-f16. the ground steering on the Falcon simulator, although it's a heavy ship and tilts with inertia on speedy taxiing, resembles/gives the feel exactly of what i felt when i tried steering on the real taxiway. so then, when i got back to FS9 steering felt like unpredictable gliding on ice:)hope we find out this line for the steering factor. i have a vague memory of downloading a vehicle, a car, for FS2002 that had absolutely no delay on the steering...hmm, i don't think it was one of the Bill Lyons (beautiful work btw), i'll look for it and if i find it i'll check the cfg file.take caresorry to interupt the discussion:)***

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Hi all,New to fs9 and am also hating the ground steering on the c172. I cannot however find the Cn_dt Yaw Moment-Thrust file in the cfg file and when I open the AIR file with wordpad it is just a bunch of mumbo jumbo. Any suggestions?Thanks in advanceGreg

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