FR Super Cub problem taxiing on bush strips

[griphos]

Well, I bought the FR Super Cub Extreme package a while back and have been flying it a bit. I was wanting a good bush plane with a little more speed than the A2A Cub, and a little more oomph for higher altitude strips.

So far, I like how the plane flies, but I've been flying it at regular airports for the most part. The past couple of days, though, I've flown it to bush strips along the Salmon river country. These are the kind of strips the Super Cub was made for, I would think. She lands fine at these strips, but when I try to taxi her to turn her around or back taxi to the end of the strip, all hell breaks loose. It's as if her tundra tires have sunk into the ground. I have to apply almost full throttle. The tailwheel lifts but she doesn't go anywhere. And no, I don't have my brakes on. When I do get her moving, it's impossible to keep her on her gear. I hold full back stick, and move at slow speed, but she'll plant her nose or start doing worse gymnastics. It's very frustrating.

These are backcountry strips, with rough terrain, but then that's what this bird was designed for, and I fly a lot of other aircraft just fine at these strips, the A2A Cub, and the Birddog, and the Scout, and the C185. Shoot, I've flown the RV-7 at these fine. I don't have any problem with any of those.

Is this a general experience with this aircraft? Does anyone know how to alter the aircraft.cfg to tame her ground behavior? As it is, these planes are unusable at the precise airstrips I bought them for and that they are designed in RL to fly at. Any help appreciated.

[napamule]

There was a MODEL update for this A/C. But if you bought it after August 14, 2011 you already have the latest files (FDE too?). After that you need to get some tips.

Like using rudder pedals with auto-coordination OFF. Or a good joy stick with sensitivities set to 100% with 0% null. Then you reduce your fuel load. Then you learn to TRIM so level flight is possible at slow speeds (stall +5). Of course throttle (power) management is also vital. You should have a way to give or take throttle QUICKLY. Then you practice touch down just as stall warning goes off. After a few weeks (months) you can fly without looking at panel and going just by sound of engine.

For finding a strip I map a joy stick (thumb) button to toggle 'top down view' and then I zoom in with '+' key. Nothing like it. Good luck.
Chuck B
Napamule

[griphos]

Thanks for the response, but you didn't read my post carefully. I have the latest version, and I don't need flying tips. I fly it fine, and land it fine. I'm a RL pilot and own a similar airplane. I have my sensitivities set correctly on controls and have pedals, etc.

There is no problem flying or landing this model. The problem is with TAXIING on backcountry bush strips. The cfg is set to respond to the uneven terrain in a way that makes it impossible. I have well over a thousand sim hours with a LOT of payware and freeware aircraft, many of them in just these kinds of strips, and have never had this problem. As long as I am on the middle of the strip, I'm okay, but when turning around or taxiing to the side of the strip, and rolling over the terrain, which is still flat enough and causes no problem for any other airplane, the FR Super Cub goes crazy, flipping and crashing.

Anyone else fly this airplane into these kind of strips and know how to modify the cfg so that the plane stays on its gear?

[bstolle]

Do you have acceleration installed? If not that would explain your problems.

[griphos]

Yes, I do. I have FSX Gold installed, and have the F-18, etc. I saw the notice on needing Acceleration before buying. But it doesn't say what problems occur without it. I thought I remembered from some threads in the past that it causes bouncing on landing. Is that right? I have no problems landing. It's taxiing that goes crazy for me, and only off the strip. I can taxi okay as long as I stay right on the strip itself, it appears. But then I can't really turn tight enough to stay right on the strip at these very narrow backcountry strips. As I've said, I taxi off the strip in these same airstrips just fine with all my other planes.

I'm happy you've responded though, since I know you worked on the FDE for these. Not sure you did anything with respect to the ground handling parameters. Have you noticed this behavior, if you've flown these planes at these kinds of backcountry strips?

I'm going to do some more experimenting with some larger airports and taxiing off the taxiways and runways and see what happens. But I've tried over a dozen backcountry strips along the Salmon River with this plane and had the problem at every one of them. Landed fine, rolled out fine, but got stuck or started flipping as I tried to taxi back into position at the end of the strip if I got even a little off the "runway."

[bstolle]

I'll re-install the Super Cub when I'm back home in a few days and check what's the problem.
I did test the FDEs off airport of course as well.
Sure you have the updated FDEs? because I didn't make the original FDEs that intitially came with the Super Cub.
Realism sliders are fully to the right I guess....

[Overshoe]

I'm going to do some more experimenting with some larger airports and taxiing off the taxiways and runways and see what happens. But I've tried over a dozen backcountry strips along the Salmon River with this plane and had the problem at every one of them. Landed fine, rolled out fine, but got stuck or started flipping as I tried to taxi back into position at the end of the strip if I got even a little off the "runway."

I just loaded up the Super Cub Extreme and the Ultra and had none of those issues at several soft airfields including 2 around Stanley, ID. I was able to taxi off the runway and across the runway and into adjacent fields with no problems. Do you have some specific fields I can try? And do you have any add-on scenery installed?

[griphos]

I bought it about a month ago, so it should be the latest version, right? Yeah, realism full to the right.

I fly in Orbx scenery.

I just tried it at several other airfields, Bowerman (KHQM) and Clam Harbor on Orcas Island, and it did fine there off airport. So I went back to the Salmon River country. I flew off from U60, and had the same problems when taxiing on the surrounding terrain up near the south end of the airstrip. I flew over to I99D, Dewey Moore, I97D, Mile-Hi, and I08, Cabin Creek. It was terrible at Dewey Moore. I landed, and when I tried to taxi up to the end of the strip to turn around to take off, I got stuck. It's as if my wheels sank into the ground. I was still on the strip, as far as I could tell, there's not much that delineates it there, but I was approaching the little tent and campfire in the Orbx scenery, on a slight uphill incline, and I could give it full power and full back stick and all it would do was raise my tail off the ground, but there was no forward motion. I had to let it coast back.

I had similar problems at the other two. Now, these are extremely rough backcountry strips, I know. But I land other planes there and taxi without problems. The people I flew with last night in MP into these same strips had no problems. And these are the kind of strips this Super Cub is made to fly into.

Is it possible that whatever settings were made to model the tundra tires are causing this behavior?

[griphos]

Okay, I did some more testing. I took a few of my other planes to these strips I listed above to try them again. It's been a while since I've flown these strips in something else. I never had any problems there that I can recall, but I tried the A2A Cub and the Real Air Scout and the Carenado C185. Both the Cub and the Scout had problems moving forward at times on several of the strips, like Dewey Moore and Cabin Creek. The C185 was fine, but then it has a lot of power. But none of the other planes displayed the tendency to start flipping when off the runway, except for the Scout, at Dewey Moore, after I slewed it a bit to get it out of being stuck. And it just started a strange tailwheel bounce that I couldn't stop.

So, I'm less concerned with the "getting stuck" bit of my experience. That may just be terrain incline and low power, although when looking from the external view, the wheels on the Super Cub seem to "sink" into the terrain a lot. It may also be the way those strips are modeled by Orbx. They may be softer or rougher than most.

I also tried 2U7 and 13ID, which may have been the two strips near Stanley mentioned above. I was okay at both, although the Super Cub was still more sensitive on those strips than my other planes.

Thanks for the help so far trying to figure out what is happening. I still think the response to terrain needs to be tamed a bit. The Cub with tundras should handle rough terrain better than other planes, not worse, I would think. As I've said, I bought the Super Cub to handle strips none of my other planes can.

I'm away from home for the next couple of days and so won't be able to do any more testing for a few days.

[Overshoe]

Is it possible that whatever settings were made to model the tundra tires are causing this behavior?

It would appear to be a combination of causes after several tests at Dewey Moore. The combination of the "tundra bounce" and the non-standard Orbx sloped runways are a recipe for disaster. The scenery is definitely a factor since there is no problem (that I have seen) at normal flattened airports. It looks like a contact point issue to me, but I'll leave it to the experts to fix. Perhaps Bernt will have an easy fix when he gets home.

[bstolle]

1. when looking from the external view, the wheels on the Super Cub seem to "sink" into the terrain a lot.
2. It may also be the way those strips are modeled by Orbx. They may be softer or rougher than most.
3. I still think the response to terrain needs to be tamed a bit.
4. The Cub with tundras should handle rough terrain better than other planes, not worse,

1. But that has no influence on drag etc. (in FSX)
2. AFAIK some of their airfields need an extremely fine mesh resolution, so if the mesh is set to e.g. 1m it might cause such problems as well.
3. That's an easy one. Just open the cfg file and alter this one in the contact points section:
point.0 = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
The red one controls the springiness of the gear. point 0 is the tailwheel, 1+2 the mainwheels.
(0 = undampened 1 = critically dampened)
4. Not necessarily. If you look at the various videos at youtube etc. you will see that the Tundra tires are nice for soft terrain, gravel etc. but as e.g. neither the Super Cub or the 185 have real shock absorbers, these tires induce 'jumping' much more than conventional tires if the tearrain is bumpy.

[robmw]

Hi,

I've flown the Super Cub Extreme extensively in the same Orbx scenery and although not as severe, I have noticed similar behaviour on rough terrain at times. I ended up doing the edits Bernt suggested to tone things down a bit which helped.

The reason I mention this is that when testing the FR Super Cub Ultra earlier this year and subsequently I've noticed that rough field behaviour is easier to control, as is landing since bouncing appears to be damped down more than with the Extreme. I'm no real world pilot but my observation of spending a lot of time with both aircraft is that the Ultra is easier for me to control. I've managed to land and manoeuvre the Ultra in places I had very limited success in with the Extreme. Maybe my skills have improved but my guess is the flight model! I realise these are different aircraft but at the same time they must have many similarities so maybe a comparison of the two is worthwhile?

Rob W

[griphos]

That sounds promising. Is it possible to put the Ultra ground/gear settings in the Extreme .cfg?


3. That's an easy one. Just open the cfg file and alter this one in the contact points section:
point.0 = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
The red one controls the springiness of the gear. point 0 is the tailwheel, 1+2 the mainwheels.
(0 = undampened 1 = critically dampened)

Okay, what settings would you suggest I alter tailwheel and main gear to?

[bstolle]

1. Is it possible to put the Ultra ground/gear settings in the Extreme .cfg?

chances that this works are approx 99%.

[griphos]

3. That's an easy one. Just open the cfg file and alter this one in the contact points section:
point.0 = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
The red one controls the springiness of the gear. point 0 is the tailwheel, 1+2 the mainwheels.
(0 = undampened 1 = critically dampened)


What do settings 9, 11, and 12 control? I believe these settings are different in the Ultra .cfg also.

[bstolle]

What do settings 9, 11, and 12 control? I believe these settings are different in the Ultra .cfg also.

Just above the [contact points] section, there's a full explanation.

//0 Class
//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

[griphos]

Thanks. I missed that. Okay, I'll experiment with these a bit, using the Ultra settings as a starting point. A few more questions, though:

What would the difference in //9 Max/Static Compression Ratio do between, say, a setting of 2.5 and a setting of 4.0?

I notice the //8 Static compression in feet is typically .06 or .07 for both the Extreme and Ultra on the tailwheel, but about double on the main gear (0.09 for the Extreme and 0.2 for the Ultra). Would you recommend the higher setting?

I also notice that the wheel radius settings for the Extreme are less than 9" (setting of 0.70). This isn't correct, is it? All of these aircraft have extreme tundra tires on them of at least 32" radius, right? Could this be having an effect on handling?

I notice the steering angle of the Extreme tailwheel is 60 degrees, but the Ultra has 180 degrees, making it free castoring, basically. Isn't the tailwheel of the Extreme Cubs free castoring as well? If I change this to 180 on the Extreme, will it allow it to turn tighter circles on the ground? It needs to. One of the reasons I wind up off the runway so far while taxiing, is that it is very hard to turn the Extreme Cub around.

I notice the Ultra has Extension times of .1 second but the Extreme has no extension times (0.0). Does this make much of a difference? Is this gear extension and retraction times? If so, neither of them has retractable gear, so the setting shouldn't make any difference, right?

[bstolle]

1. I also notice that the wheel radius settings for the Extreme are less than 9" (setting of 0.70). This isn't correct, is it? All of these aircraft have extreme tundra tires on them of at least 32" radius, right? Could this be having an effect on handling?
2. I notice the steering angle of the Extreme tailwheel is 60 degrees, but the Ultra has 180 degrees, making it free castoring, basically. Isn't the tailwheel of the Extreme Cubs free castoring as well? If I change this to 180 on the Extreme, will it allow it to turn tighter circles on the ground? It needs to. One of the reasons I wind up off the runway so far while taxiing, is that it is very hard to turn the Extreme Cub around.
3. I notice the Ultra has Extension times of .1 second but the Extreme has no extension times (0.0). Does this make much of a difference?

1. That wheel size is incorrect (leftover from the standard PA18 I'd say) but it has no effect on handling.
2. The Super Cub has a 'special' steering which can't be duplicated in FSX, so it's your choice what you prefer or what's easier for you. Taxiing with a free castoring tailwheel is much more difficult but it's easier to turn on the spot.
3. You can disregard these numbers.

Again, I suggest adjust only the damping ratio to your liking (and the tailwheel steering) as most other values interact with each other!

[griphos]

Thanks again for the help. I changed the tailwheel angle to 180 but that seemed to make it harder to turn. Go figure! I put it back to 60 but may try 80 or 90 just to see.

I changed the wheel size to correct, and although it may not affect handling, the wheels now sit on top of the ground in external view.

I changed the dampening, but also the compression settings to match the Ultra. There is a definite improvement as a result. I only got the flipping once on testing again at these strips, and that was after slewing to a flatter, but apparently still rough spot, after getting stuck again.

She's still more sensitive than I think she should be, certainly more than my other planes, and still has a tendency to dive on her nose even with full back stick, but she's at least flyable into these strips now.

[bstolle]

1. I changed the tailwheel angle to 180 but that seemed to make it harder to turn. Go figure!
2. I changed the wheel size to correct, and although it may not affect handling, the wheels now sit on top of the ground in external view.
3. She's still more sensitive than I think she should be, certainly more than my other planes, and still has a tendency to dive on her nose even with full back stick, but she's at least flyable into these strips now.

1. That's what I said. More difficult to taxi as there's no connection between the rudder and the tailwheel. For really tight turns you need a burst of power, apply full rudder and differential braking.
2. That' really weird. Tried and didn't notice any difference in appearance (not even by increasing the size by 1ft)
3. The Super Cub has a trimmable stabilizer! Without re-trimming you run into serious controllability problems even with full back stick. That's one of the reasons I've deleted all of my Super Cubs except for the standard one. She's easily the most beautiful and nicest handling of all the available variants.

[griphos]

1. Ah. Well, the burst, full rudder, and diff braking doesn't work as well off strip when she's having trouble just moving forward.

2. It was only sinking below ground level on the rough strips, so you may not have noticed it, but the ground often came up to the hubs (about half the wheel sunk) on the rough strips, even on the runway sometimes, but hasn't since I changed the size, although I haven't flown it that much yet.

3. I only experience the nose diving while taxiing. I'll try trimming nose up while taxiing and seeing if that makes a difference. But I'm trimmed fairly nose up from landing trim anyway. Well, I should have gotten the standard one, then, I guess.

[bstolle]

These sinking-to-the-hub and getting stuck problems look very much scenery related to me. Tried everything but couldn't even remotely replicate your problems. I'm really sorry!

[griphos]

Probably. This is Orbx scenery, and I don't know how their mesh works at all.

I don't think the getting stuck is related to the wheel-sinking. I think the wheel sinking is just graphical interfacing. Try it at I97D or I99D with the original settings.

I think the getting stuck is because these strips I'm flying into don't have any flattens and are sometimes steep. They are installed on the terrain itself so that they replicate the real strips, which are anything but flat. Basically just paths in the surrounding terrain, so I suspect that the "ground" is rougher there than at any regular airstrip, even grass and dirt strips in most of FSX. I get stuck when trying to taxi up inclines. It's weird though, as sometimes I have no trouble on fairly steep inclines, and sometimes I get stuck on fairly shallow inclines, so I suspect it's a combination of incline and whatever settings determine the "roughness" of the terrain. I've noticed that it seems worse in the parts of the terrain that have the "forest" green mottled graphics than on the parts that have the "grass" graphics. But I get stuck in other planes here as well. So, getting stuck is very likely scenery related.

[Vox]

Hi you all,

I read carefully these 2 pages and I'm here reviving this thread just to make sure about the happy end of it and to give my contribution:

I have experienced the exact same facts that Griphos described and not on Orbx sceneries.
Same behaviour applies: perfect flight, perfect landings, perfect taxiing on tarmac, but when it comes to taxiing off the runway in some cases it's impossible to move and when you manage you end up flipping over and crashing.
I'm talking about Flight Replicas Super Cub, standard version (not tundra). I only have the A2A Cub to make a comparison with and this have absolutely no problem to cope with the roughness that makes FR Cub crash.

I don't have FR Super Cub Ultra to make comparisons with or to switch .cfg file settings with. So I'm here asking if any of you happened to find the final solution to the problem because even though I've read that the Ultra version has none of these issues whatsoever, I'm not planning to buy it.

Thanks for the attention

Christian

[griphos]

Hello Christian,

I made the changes you read about above, and it did improve things, but I've basically stopped flying it. I bought it to fly at the backcountry airstrips (such as it would be used in RL) and its ground handling at those remain far too touchy. I just fly a few of my other planes into those sort of strips now.

[fliger747]

Nose up trim from landing? Super cubs require a bunch of nose down trim cranks with flap extension from the initial descent approach settings, however this usually ends up somewhere near the appropriate takeoff trim. Any load is distributed aft, also requiring more nose down trim. This can be a lot but since the stab is trimmed and full elevator is still available reasonable good pitch control is retained. Probably because of the thick airfoil cubs still seem to have good pitch stability at aft CG locations. Some of the high HP (heavy engine) planes can be a bit fwd CG when empty.

An AOA indicator is available for about $1400, thinking of getting one as the plane usually has a lot of flying left at an IAS of 40 mph, which is the point at which the AS indicator really loses interest. Not so important for float flying, so much cub flying is about how it feels, which is hard to replicate in FS.

Still fun planes! T

[mike_cyul]

Given that FSX aircraft are fundamentally all identical when it comes to the gear animations and contact points (it's really just a matter of putting in the correct numbers to get the location, appearance and movement you want), I'm wondering if there isn't something else to try: suspension, gear travel, damping, etc., are one thing, but what about the scrape points?

I can't replicate this problem, and neither can anyone else I've asked (and I think there's only been two reports to Support in total), but as it's seems pretty likely a simple conflict somewhere between aircraft and terrain meshes, why not try, just as an experiment, to swap out the scrape points (usually point.3, on down, for the taildragger) with an aircraft or similar size that works? Just to see if the conflict is still there. Of perhaps even try taking out the scrape points entirely. Perhaps one is dragging too low for the terrain mesh altitude or something similar?

Mike

[HighGround22]

.
I'm fascinated with this thread, and I hate to be a stick in the mud, but . . . .

FWIW, I'm +1 with Griphos' problems. I have the FR Super Cub Ultra and had to stop flying it -- for the same reason as his: I wanted to use it as a bush-strip plane, but got frustrated with the aircraft "bogging-down" and/or thrashing itself to death.

Been doing this stuff since early FS9, so it was quite a surprise to see myself with so little control of an airplane, in the aforementioned instances.

After repeated tries, alas, I just found myself ignoring the plane.

[bstolle]

I've pm'd a few customes with this problem but apparently this doesn't happen with any default dirt strip, only orbx airfields. As I'm not using any of these anymore I can't test. Seems to be a very restricted mesh problem.
You can soften the shock absorbers almost indefinitely so that they always 'work' on any ground but especially the tundra wheels are very springy IRL.
It's simply impossible to set the damping correctly for all ground variations as FSX does apparently have serious problems with non-standard meshes.

[mike_cyul]

.
I'm fascinated with this thread, and I hate to be a stick in the mud, but . . . .

FWIW, I'm +1 with Griphos' problems. I have the FR Super Cub Ultra and had to stop flying it -- for the same reason as his: I wanted to use it as a bush-strip plane, but got frustrated with the aircraft "bogging-down" and/or thrashing itself to death.

Been doing this stuff since early FS9, so it was quite a surprise to see myself with so little control of an airplane, in the aforementioned instances.

After repeated tries, alas, I just found myself ignoring the plane.


Try the scrape points as mentioned above. It has to be something pretty simple.

[HighGround22]

Try the scrape points as mentioned above. It has to be something pretty simple.

Yeah, Mike, that's my sense of it.

I'll have a boo at yon points.

Anon.

[griphos]

Yeah, I'll try that too. It will be this weekend before I have time, but I'll report back.

It could be mesh problems with Orbx, in particular, I suppose, but I suspect that the Orbx backcountry airfields I'm flying to are really just terrain without any leveling or other airfield adjustments. It might be worth trying to land the Super Cub away from airports in non-Orbx terrain to see if the the problem can be replicated there.

[fliger747]

The springiness of bush wheels (Ok I run Goodyears..) varies a lot with air pressure. The lower the pressure the more bean bag like. Less springy and better surface flotation, but more rolling ristance. Contact points cannot makeup for terrain mesh errors. You might try changing the mesh resolution in the display parameters. If The contact points work OK on the various default surfaces, that' about all the designer can do.

T

[mike_cyul]

It might be worth trying to land the Super Cub away from airports in non-Orbx terrain to see if the the problem can be replicated there.

We did a great deal of the testing (especially the Extreme and Bush aircraft) on non-airport mesh, all over the FSX world, as it was pretty obvious that's where users would be flying, and didn't have any problems (and to date, it appears neither has anyone else). Then again, the aircraft were also flown from Orbx airports (I have Australian and North American airports on my computer) without issue, too, so who knows!

Mike

[griphos]

<snipped irrelevant="" stuff="" about="" actual="" plane=""> Contact points cannot makeup for terrain mesh errors. You might try changing the mesh resolution in the display parameters. If The contact points work OK on the various default surfaces, that' about all the designer can do.

T

I don't even know what a "mesh error" would be. I'm not talking about abrupt changes in elevation. It's relatively flat land with dirt or grass runways on it. I use the mesh resolution that is stipulated by the scenery. Again, I don't have this problem with other aircraft I fly into these same strips.

I'll try using some settings from the other aircraft as a test, though, as I said.</snipped>

[olderndirt]

This from a forum member at 'Bushpounders Flying'. Certainly makes it turn.

"Well, slap my hand. I couldn't change the tailwheel because I was changing the wrong parameter! I no good way to modify .cfg files. http://i601.photobucket.com/albums/tt96/pivo11/Faces/Doh.gif
So. To make the tailwheel steerable with the rudder, in the [contact_points] section of the .cfg file, change the 7th entry of line point.0 from 180 to 60. (Example below) This changes the steering angle and the number is the deflection in one direction, so 60 means that you have 120° from full left to full right. The higher the number, the sharper the turn. I find that after 60, the steering gets too sensitive, but that's just me. 180 makes the wheel free castering.

[contact_points]
point.0=1, -15.85, 0.0, -1.05, 1800, 0, 0.256, 180.0, 0.07, 2.5, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0"

[contact_points]
point.0=1, -15.85, 0.0, -1.05, 1800, 0, 0.256, 60.0, 0.07, 2.5, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0

[fliger747]

Example of mesh errors, I remember flying a chopper about in the alps, some places the visual and hard deck do not coincide, the skids sinking into the terrain a foot or so. When developing contact points I always test a lot of places, I am sure Mike did this.

T

[fliger747]

Further point on tail wheel steering...

Though a cub has tailwheel steering, FS does not replicate it well. IRL it is through springs an is somewhat approximate and castors beyond a certain angle. Having periodically disassembled these tailwheels for cleaning and lube, they break free somewhere around 60 deg. FS steering is far too powerful and precise and does not break free.

My opinion as an experienced and current cub driver is that the 180 castoring CFG value best replicates the experience. Feel free to disagree.

T

[mike_cyul]

I've been talking with Wozza, who knows more about terrain mesh than I do, and one potential source for a problem could be that in FSX the terrain mesh loads after the aircraft mesh. In other words, it lags behind the aircraft mesh. This is why aircraft jump sometimes when switching views: the terrain comes up after the aircraft loads and hits the contact and scrape points. Not too sure if it applies directly here, but it does help illustrate that there are differences in behaviours between the two mesh types in FSX.

Another thing to try is increasing the Impact Damage Threshold (Feet Per Minute) in the contact points. This is the parameter highlighted in red below, on a [contact_points] line:

point.0=1, -15.85, 0.0, -1.21, 1800, 0, 0.256, 180.0, 0.07, 2.5, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0

Try increasing this to a much higher number, such as 9000, and see if that makes a difference.


Mike

[dandog]

I99D is not a landing strip/field. It's a river bank. ANYTHING I tried load there on the "strip", sank into the ground. I think the campfire is the remains of a botched landing. The other nearby "landing areas" were not nearly as bad, I98D, I97D, and I96D. They were usable, needed full power and a prayer to move around, but do-able. IMHO, it is not an issue with the FR Cub, any of the different flavors, but the scenery.

Daniel.

[griphos]

I think the campfire is the remains of a botched landing.

Daniel.

:-)

That's pretty funny. As I've said a couple of times, I land in those places fine with other aircraft. So, it's not the scenery, I don't think.

[griphos]

Okay, I have a little time to test. So, to make sure I'm understanding, Mike suggested changing the scrape points. Am I right in understanding that to mean basically replacing point.3 through point.10 with the values from some other plane?

Bernt suggested changing the shock absorber settings. I can't tell from the key in the .cfg which contact points I would change to do that and what I'd change it to in order to soften them.

I tried changing the impact damage threshold to 9000 (from 2500) but that made no difference.

[griphos]

Okay, I swapped point.3 through point.8 with the ones in the Carenado C185 Tundra (it only went to point.8) since that was also done by Bernt (I have his latest .cfg file for that aircraft). The result is that it handles much, much better! I flew to about five different strips there around the Salmon river and she did well at all of them. There was only one incident of crazy gymnastics crashing like I usually experience, and that was at the first strip, Mile Hi (ID97) when I first tried to turn around at the top of the strip. Not sure what happened there, and I was worried, but I landed there two more times and taxied around. I landed at four other strips and taxied around. I never got stuck once, nor did I ever tip over again. I even took off at several strips without staying on the runway to see how it would do "off airport." It did fine.

Here are the original settings in the Experimental version:

point.3=2, -1.0, 17.0, 1.90, 2000, 0, 0.000, 0.0, 0.00, 0.0, 0.000, 0.0, 0.0, 5.0, 0.0, 0.0
point.4=2, -1.0, -17.0, 1.90, 2000, 0, 0.000, 0.0, 0.00, 0.0, 0.000, 0.0, 0.0, 5.0, 0.0, 0.0
point.5=2, 5.4, 0.0, -2.45, 2000, 0, 0.000, 0.0, 0.00, 0.0, 0.000, 0.0, 0.0, 6.0, 0.0, 0.0
point.6=2, -15.38, 0.0, -1.00, 2000, 0, 0.000, 0.0, 0.00, 0.0, 0.000, 0.0, 0.0, 9.0, 0.0, 0.0
point.7 =4, 0.95, 2.75, -4.55, 4200, 0, 0, 0.0, 0.3, 2.5, 0.90, 0.0, 0.0, 3, 0, 0
point.8 =4, 0.95, -2.75, -4.55, 4200, 0, 0, 0.0, 0.3, 2.5, 0.90, 0.0, 0.0, 3, 0, 0
point.9 =4, -1.0, 17.0, 1.90, 1600, 0, 0, 0.0, 0.0, 0.0, 0.00, 0.0, 0.0, 5, 0, 0
point.10=4, -1.0, -17.0, 1.90, 1600, 0, 0, 0.0, 0.0, 0.0, 0.00, 0.0, 0.0, 5, 0, 0

I left point.9 and point.10 unchanged (since the C185 didn't have those). They are Max/Static Compression and Damping ratios.

Here's what I put in from the C185:

point.3 = 2, -4.60, -17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 5, 0, 0 //LW
point.4 = 2, -4.60, 17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 6, 0, 0 //RW
point.5 = 2, 1.2, 0.0, -2.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 9, 0, 0 //tail
point.6 = 2, 1.2, 0.0, -2.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 4, 0, 0 //Fslg
point.7 = 2, -18.75, 0.0, 6.45, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 7, 0, 0 //Aux1
point.8 = 2, -14.12, 0.0, 0.01, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 8, 0, 0 //Aux2
point.9 =4, -1.0, 17.0, 1.90, 1600, 0, 0, 0.0, 0.0, 0.0, 0.00, 0.0, 0.0, 5, 0, 0
point.10=4, -1.0, -17.0, 1.90, 1600, 0, 0, 0.0, 0.0, 0.0, 0.00, 0.0, 0.0, 5, 0, 0

You can see almost every value is different. I have no real idea what any of this means. I'm not sure if any of this would make the Super Cub unfaithful to RL. But it does seem to work. The plane sits correctly on the ground from outside view every time I checked.

I'll keep experimenting with it, but it's nice that perhaps the plane will now work for the purpose for which I bought it.

[Roger]

Heck of a strip I99D! I tried a tundra tyre version and the only problem I had was with negotiating the runway's slopes in both axes:

http://i6.photobucket.com/albums/y203/rogera/Scub-tundra-1.jpg

[griphos]

Yes, there's not that much slope there, though, really. Most planes I fly there don't have an issue with it, and the Super Cub doesn't either with the new contact points.

[Vox]

This is all getting more and more interesting! :-)

I'll surely try the scrape points and the impact damage threshold mods (even if I'm always testing without switching between views and it doesn't make things better) but, as for the orbx and other custom mesh and terrain discussion, I'd like to point out again that A2A's Cub rolls smoothly on any surface which, as a matter of fact, moves the question off the accuracy of the mesh design and on to other matters that might still be the contact points or even the FDE.
In my tests on a custom airstrip that I happened by chance to find as a candidate, I see that only the Extreme versions of Flight Replicas' Super Cub are able to overcome the bumps without flipping over (though still not as smoothly as the A2A's) but all the other Cubs (Standard and Classic, sorry I don't have Ultra version, is that so different from the Extreme?) just can't.
I'm trying to make a video of the comparison because that would be worth a thousand words.

Christian

[dandog]

Here are some shots took that make me believe it is a scenery issue. After loading each plane, I cycled through all the views, after which they would sink. I am sure that many of the aircraft will look familiar. I am not trying to be a PIA (plane in the a$$), but would like to see a remedy too. Again, that had better be a good shipment of heroin to get me to try to land at I99D.:icon_lol:

[griphos]

I see what you're talking about, but I don't think the phenomenon of "sinking" has anything to do with the problem. I can change whether the wheels seem to "sink" by changing the radius of the wheels in the contact points. But that will affect what the wheels look like on "paved" surfaces as well (it makes the appear above the ground). I've never had any issue of being stuck or flipping follow from this graphical "sinking." I have those problems many times when there is no "sinking."

I believe (of course, I don't really know) that this is a simple matter of visual harmonizing. As discussed in posts in this thread in the high teens and low 20's, it appears that sometimes the drawing of the plane skin and the ground "skin" sometimes don't line up. This is more pronounced on rough strips or off field. Sometimes, the tailwheel is above the "ground" but is actually riding as it should on the actual mesh, just not the graphical "skin" of that mesh. Sometimes, the gear "sink" into the ground, but are actually rolling just fine on the actual mesh. I suspect that in all the cases you picture above, the planes were rolling just fine and not "stuck" in any way.

So, whatever is causing the bad handling isn't in the mesh, I don't think, since planes that do sink for me, as in your pictures above, still don't have any trouble rolling on that terrain and don't get stuck or flip over as the Super Cub not infrequently did before I changed the contact points today.

[dandog]

I'm using FSGX2010 as mesh. How do I get ORBX To Co-operate.

[bstolle]

Here are the original settings in the Experimental version:

point.3=2, -1.0, 17.0, 1.90, 2000, 0, 0.000, 0.0, 0.00, 0.0, 0.000, 0.0, 0.0, 5.0, 0.0, 0.0
......
......

Here's what I put in from the C185:
......
......
point.3 = 2, -4.60, -17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 5, 0, 0 //LW

1. The result is that it handles much, much better!
2. I can change whether the wheels seem to "sink" by changing the radius of the wheels in the contact points



1. If you really left out the first 3 contact points all the changes you made can change nothing concerning the taxiing behaviour because you only exchanged the scrape points of the wings etc.
There's not a single change the concerns the wheels so this a pure placebo effect! Using contact points from different planes is a very bad idea.
At best you could try to use the static compression, compression and damping ratio from another plane but not even that is recommended.
2. Again, this is a placebo as changing the tire radius has no effect on the visual model concerning the way she sits on the ground

Here are the numbers for the standard super cub

point.0=1, -16.0, 0.0, -0.83, 2500, 0, 0.256, 60.0, 0.06, 2.5, 0.3, 0.0, 0.0, 0.0, 0.0, 0.0
point.1=1, 0.9, -2.95, -4.55, 2500, 1, 0.70, 0.0, 0.09, 4.0, 0.2, 0.0, 0.0, 2.0, 0.0, 0.0
point.2=1, 0.9, 2.95, -4.55, 2500, 2, 0.70, 0.0, 0.09, 4.0, 0.2, 0.0, 0.0, 3.0, 0.0, 0.0

Change all the red values (damping ration) to 1.0 and let me know how that works (same goes for all Super Cub version without ruining anything)

[griphos]

No, I didn't leave out the first contact lines, of course. I simply did what was suggested by Mike, which I believe was to put in the contact points from another plane starting with contact.3. He is the one who suggested to use the values from another plane. I just listed the old values and the new values for the points I changed.

I'm not saying that changing the wheel radius affects the handling. It does affect whether the wheels appear above or below the terrain (or seem to "sink"). I know they don't for you, according to an earlier post, but it's not a placebo effect. It's not as if I can't tell the difference between whether the wheel sinks below or sits on top of the ground.

I will make the changes you suggest. However, making the changes I made did indeed affect the handling. I haven't tested it for long, but I tried all the airports today before making the changes, and the plane exhibited the same problematic behavior as before. Almost uncontrollable on taxiing around these strips. I made the change to the impact damage threshold in point.0 as suggested, and tried again and there was no improvement, so I changed that back to the default 2500. Then I changed contact points .3-.8 with those from the C185 and flew the same five airstrips, and one of them for several landings and the behavior of the plane was very different. Pretty much what I experience from the C185 when I fly it into these airstrips. No trouble really in ground handling any more and no tipping over while taxiing or flipping and crashing, as used to happen most of the time. No getting stuck.

I don't know what to tell you. I didn't expect it to work. I've tried everything suggested in this thread and by pm before without any real improvement.

I'll test some more when I get a chance this weekend.

[bstolle]

1. No, I didn't leave out the first contact lines, of course.
2. I'm not saying that changing the wheel radius affects the handling. It does affect whether the wheels appear above or below the terrain (or seem to "sink"). I know they don't for you, according to an earlier post, but it's not a placebo effect. It's not as if I can't tell the difference between whether the wheel sinks below or sits on top of the ground.
3. However, making the changes I made did indeed affect the handling.

1+3. As you didn't post the important changes (wheels!) I can't tell what's the difference....Changing the wing scrape points doesn't do anything.
2. Place the Super Cub on a 'real' runway and change the tire radius to 0.0ft and to 3.0ft....there is no difference in handling or the way she's sitting on the runway!

[griphos]

Look, I am not an idiot. I have said repeatedly that I don't think changing the wheel radius does anything to affect handling. It does affect visuals. I believe I have even tried it on regular runways but its been a while so I'll check again. FSX is a strange beast. We all have it modified far beyond its original condition with so many addons interacting with each other I sometimes think it's a wonder it works at all, and sometimes it doesn't.

As to what could have changed the behavior, I realize it is highly unlikely to be scrape points. It was not my idea to try changing those. Mike suggested it. According to your own notation in the C185, though, point.5 is a tail scrape point, not a wing scrape point. It makes sense to me that perhaps the tail scrape point COULD affect ground handling. I will change all the points back but that one as I have time later and try again. Point.6 is "fslg." I don't know what that is, but perhaps it is landing gear. If so, that could reasonably affect ground handling. I don't know what Aux1 one Aux2 would be (point.6 and point.8.)

I realize it is frustrating to diagnose and resolve problems remotely, when so many variables are possible and systems vary so much, but not every FSX user with a problem is a 70 year old senile old man (apologies to the senile old men users out there)! I am not, for instance. I'm actually quite savvy, while not being a software engineer. I am usually able to diagnose and resolve almost all my problems on my own. This one has stumped me until Mike suggested swapping these scrape points.

My testing is very limited so far. I don't want to claim the problem is resolved, and certainly not by virtue of such wholesale swapping of data points. But in that limited testing, there was significantly different behavior on the same strips.

[bstolle]

According to your own notation in the C185, though, point.5 is a tail scrape point, not a wing scrape point. It makes sense to me that perhaps the tail scrape point COULD affect ground handling

All scrape points except 0, 1, and 2 just define the important edges of the model, like wingtips, tailcone, cowling. E.g. if you don't have a retractable gear, the tail scrape point doesn't have any ground contact during taxiing.
Concerning senility, believe me, this affects me already as well !! :)

[fliger747]

I understand from a developer that I work with that wheel radius does affect the wheel rotation animation.

T

[bstolle]

Exactly. With the radius you adjust the wheel RPM so that it looks correct if not locked or static ;)

[mike_cyul]

Some more ideas from Wozza:

Something else to try is commenting out the float points in the gear section, and comment out the gauge01=FR_SC!dip, 1,4,3,6 in the Panel.cfg vcockpit2 section, as it's possible the gear is being raised as there is pools of water or a water layer under the terrain which is causing the gear to go up and the floats contacting the ground.

It could also just be the terrain hitting the floats (main reason for getting stuck they may need to be raised a little)....if still no luck then try a test with crash detection switch off (in Options) it maybe a crash bubble issue.


Mike

[Milton Shupe]

Sorry to jump in here but if we are talking about the Tundra version, would someone check this crash point. Seems the crash point is lower than the tail wheel and that would be a problem.


point.0=1, -15.85, 0.0, -0.93, 1800, 0, 0.256, 180.0, 0.07, 2.5, 0.5, 0.0, 0.0, 0.0, 0.0, 0.0
point.1=1, 0.95, -2.95, -5.41, 3600, 1, 2.90, 0.0, 0.20, 2.5, 0.3, 0.1, 0.1, 2.0, 0.0, 0.0
point.2=1, 0.95, 2.95, -5.41, 3600, 2, 2.90, 0.0, 0.20, 2.5, 0.3, 0.1, 0.1, 3.0, 0.0, 0.0
//scrape
point.3=2, -1.0, 17.0, 1.90, 1600, 0, 0.000, 0.0, 0.000, 0.0, 0.000, 0.0, 0.0, 5.0, 0.0, 0.0
point.4=2, -1.0, -17.0, 1.90, 1600, 0, 0.000, 0.0, 0.000, 0.0, 0.000, 0.0, 0.0, 5.0, 0.0, 0.0
point.5=2, 5.4, 0.0, -2.45, 1600, 0, 0.000, 0.0, 0.000, 0.0, 0.000, 0.0, 0.0, 6.0, 0.0, 0.0
point.6=2, -15.38, 0.0, -1.00, 1600, 0, 0.000, 0.0, 0.000, 0.0, 0.000, 0.0, 0.0, 9.0, 0.0, 0.0

The total suspension for the tail wheel is .175' (.07*2.5). Since .07 is very stiff, just sitting on the tarmac would place the wheel touch point at (-.93 + -.07) = -1.0.

The crash point would be at or very near the ground even though it is .47' in front of the tail wheel.
With rough terrain or bouncing, the crash point would likely be making contact.

Try changing the crash point statement to this:

point.6=2, -15.38, 0.0, -0.50, 1600, 0, 0.000, 0.0, 0.000, 0.0, 0.000, 0.0, 0.0, 9.0, 0.0, 0.0

This gives you some room (about 6") to play.

Regarding the Floats points in the same cfg, the numbers of some are the same as the crash point locations.
This would cause serious drag.

EDIT: You might just try to comment out the crash points (type=2 points) on whatever version you are flying to see if this resolves your issue.

[bstolle]

Now that's an interesting find! The tailscrape point is essentially in the same position as the tailwheel. Makes absolutely no sense.
If this is present in any Super Cub cfg, it can be safely deleted.
Thanx for the heads up Milton :)

[griphos]

Well it seems as if this could well be the issue. I will test this out thoroughly. It would explain why changing the contact points I did with those from the C185 seemed to resolve the issue.

I ran out of time to do any more testing this weekend. I had several MP sessions I w responsible for, and the release of the Milviz Sabre and Orbx W Yellowstone distracted me a fair bit. :-).

[Vox]

Well, guys,
I must confess that after extensive testing I'm not really satisfied.
I mean that FR Super Cub is overall a great machine but I didn't manage to fix the weird behaviour on the ground in order to make it complete...at least the standard version.
I tried to change the scrape points but I sensed an unrealistic result;
I tried to remove the scrape point.6 but the tail started to sink in the ground;
I tried to change the damage threshold but it made it always too jumpy;
I added a float section like in the Extreme model but the tail started to softly lift up with little throttle;
The only thing that seemed to change something was the damping ratio but, first, it only dampened the problem (I still use the Extreme and the Experimental as a terms of comparison) and secondly it seemed like after some taxiing the issue would come back making me think that there must be a connection between the contact points and the FDE which cannot be overridden.

BTW I discovered that by assigning a steer angle of 180.5° to the point.0 (as "suggested" by the Experimental cfg) you happen to "unlock" the tailwheel in a way that it follows the movement of the rudder all the way back and forth so that the handling becomes much easier and differential braking is no more necessary. But some real Cub pilot suggested that it is convenient but not realistic a behaviour.

So I decided to keep things as they are and use the Extreme and the Experimental models if I know I'll have ro deal with very rough terrain and the Standard/Classic/Float if I'm sure I'll be taxiing on smooth surfaces.

This at least until FR will find an official solution or I'll decide to get the Ultra package.

This is it for the moment.

;)
Christian