F-18C weird behavior
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?? you dont understand that gear damping is part of the flight model ?
Not really…it seems to depend on the approach taken to the Flight Model (and/or setting of boundary conditions?). I’ve flown sims where the aircraft seems to literally “fly on the ground” - both X-Plane and the Trainer I fly currently do this, and I can see geear damping being part of that approach - and others where the aircraft seems more stuck/stable to or on the ground plane - i.e.; the BMS Viper, MSFS, Graphsim Hornet 3.0, T-45A Trainer, etc.
What I don’t know is which approach you’ve taken, or if there is any difference in approach between the BMS Viper and Hornet modelling.
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Is it safe/possible to take off like this … or does it oscillate out of control?
Is there an easy edit to the *afm file, we can make? (Maybe something for the Fighter Mafia crew to track and distribute?)
not happening while taking off
My experience has been this “wobbling” issue only occurs at certain speeds. About 1-30…ish kts…and Unfortunately there is no fix that we can make at this time. So as long as you keep the nose pointed strait down the taxiway/runway with rudder pedals below 30 kts you’ll be able to take off.
Also, this issue isn’t as bad on the carrier. It only seems to be this severe on land. So essentially the F-18 in BMS does not have “land-legs”. :mrgreen:
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This doesn’t surprise me in that you spend far less time rolling on the cat, and probably transition through the offending region very quickly.
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Based on my own experience with game physics engines … my guess is there is very specialized code to keep planes glued to the carrier deck as it moves, pitches and rolls. Compared to just rolling along solid ground.
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Possibly…but that doesn’t explain the differences in sims that I see that stick to a ground plane solidly and ones that seem to “fly” along the ground. This was one of the first things I noted about the behavior of X-Plane when I started playing with it. Not to mention that RL Hornet gear are pretty “spongy” - so if the gear are modeled well you should get some spring as the carrier deck pitches and rolls even though you are stuck to the deck…if not chained down. It smacks of different approaches in modelling, to me. I’ve been exposed to a LOT of sims/Trainers over the decades.
Anyway, the “behavior” in the video looks like AOC getting coupled into the aero model when it shouldn’t be - only because RL AOC is only invoked under these types of heavy stores loadings, and nobody has remarked on seeing this with lighter loadings or as SOP with the model…to relate it to the RW. And if the gear model also has a problem I should think that only aggravates things.
Not saying this has to be the case, only what it looks like. I have no idea of the extent of the actual modeling, though I do still believe it’s not as extensive as I’d like to believe it to be.
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Based on my own experience with game physics engines … my guess is there is very specialized code to keep planes glued to the carrier deck as it moves, pitches and rolls. Compared to just rolling along solid ground.
There is no special physics code for carriers it’s the same
This bug is a gear data amortization / stiffness issue
That’s amazing noeone listen to me LOL I created the thing !!
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There is no special physics code for carriers it’s the same
This bug is a gear data amortization / stiffness issue
That’s amazing noeone listen to me LOL I created the thing !!
Yeah yeah, that’s what they all say:D
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@Jp: Tell them to fix it themselves by playing with data …
It will takes longer, but they will see that it is not a matter of special code. -
There is no special physics code for carriers it’s the same
This bug is a gear data amortization / stiffness issue
That’s amazing noeone listen to me LOL I created the thing !!
?
I didn’t mean to sound like I was refuting, or replying to anything you said, Mav. Obvs it’s just bad data for gear dampening or stiffness … I was just hypothesizing why it might not be so evident on carrier deck, vs solid ground.Pretty impressive that BMS physics engine works well enough for moving objects to rest and roll atop one another… I appreciate how tricky that is to get right.
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The problem with the f18 gear is the extreme course it has
In order to have this extreme course and compression I was obliged to define a very low stiffness in a wide range of the compression and then increase stiffness a lot in the second range
This creates unexpected behavior like extreme rolling when turn , wobbling ….
If you increase the stiffness « 1 » and increase defzone1 to 0.8 it should stop
Problem is that the model will not sit like the real then
You can also try to increase amortization in detent vs compression
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