Aircraft shakes and wobbles with engine off

[KiltinSA]

Hello and thank you for activating my account!

I wanted to let you know that I'm running Flight Simulator FSX with SP2. I recently purchased your wonderful product and noticed that the Fw 190 shakes and wobbles considerably from side-to-side - even when the aircraft engine is off.

The instruments shake as well when looking at the virtual cockpit.

Aside from these minor issues, this is a fantastic example of the Fw 190 for FSX...thanks for making it!

Cecil

[Mathias Pommerien]

Welcome aboard Cecil!

Well, it's a known issue due to an FSX bug, it's been talked about here:
http://www.classics-hangar.de/phpBB3/vi ... ?f=12&t=85

To work around the issue you can open each aircraft.cfg in a text editor,
locate the weight_and_balance section and look up the moments of inertia values.
They are different for each aircraft.
Here's an example of the A-1:

empty_weight_roll_MOI = 2470
empty_weight_pitch_MOI = 4387
empty_weight_yaw_MOI = 6548
empty_weight_coupled_MOI = 113

Changing the empty_weight_yaw_MOI to at least 12000 should take care of the shaking.
However, we don't feel very confortable with this tweak as it affects the plane's flight physics.
Basically it'll become somewhat more stable and less agile that's why we do not offer this as an "official" patch.

[KiltinSA]

Thank you Mathias.

I adjusted the empty_weight_yaw_MOI to 12000, but that had no effect on the wing wobble. So I also adjusted the empty_weight_roll_MOI to 4000. That fixed the wing wobble issue!

The impact on aircraft performance is acceptable. To compensate for the loss of agility, I adjusted the flight_tuning parameters - specifically the aileron_effectiveness and rudder_effectiveness values.

Overall, I'm very satisfied with these modifications and can't wait to see what comes out of Classics Hangar next!

Cecil

[Mathias Pommerien]

Interesting that some user machines require different settings to work around it.
On a sidenote, I'm running FSX on 3 machines, one each with XP, Vista home premium and vista ultimate 64.
They all act differently.
The 64b machine doesn't show any shaking at al, the XP machine shows it just barely noticeable and the vista home laptop shakes badly.
I tend to believe that it's caused by CPU/GPU load as the amount of shaking on the various machines pretty much translates well in how good they perform FSX.

[mjolner]

The 64b machine doesn't show any shaking at al, the XP machine shows it just barely noticeable and the vista home laptop shakes badly.
I tend to believe that it's caused by CPU/GPU load as the amount of shaking on the various machines pretty much translates well in how good they perform FSX.

In regards to the above comment, does this infer that wobble/shaking is proportional to bad performance or better performance in FSX in terms of FPS?

*****************************
Hello

I am new here. Recently purchased the FW190. I must admit that I have as many questions about your product as I have praise for its attention to detail and fine modelling. Until I have collected my thoughts and questions in an orderly manner I will suffice to say that I am impressed by many aspects of this fine re-creation and for me it is like stepping into History.

Thank you Classic Hangar

V/R
Sean

[Mathias Pommerien]

Welcome Sean, and thank you for your nice commends!

In regards to the above comment, does this infer that wobble/shaking is proportional to bad performance or better performance in FSX in terms of FPS?


V/R
Sean

Yes, that's what we see on our rigs, the smoother FSX runs the less shaking you see down to no shaking at all.
It appears as if one of the first things FSX cuts down when there's drain on the machine is the aero code.