Instability of giant fairings - Kraken food?

[Magzimum]

So I have an Eve lander for 3 Kerbals, with a rather un-aerodynamic mothership attached to it. It needs to be launched, and for fun I would like to avoid the "going up straight until drag is no longer an issue". So I put a huge fairing around it.

But that thing is giving me a headache. The payload inside wobbles - it's moving from side to side already on the launchpad. Autostrut or real struts don't seem to do much. And if I strut it too much, it just explodes on the launchpad. 

Because of Eve's ridiculous atmosphere the ship has giant wings on the top, so it is an aerodynamic disaster. Removal of the fairing therefore results in flipping as soon as start something that resembles a gravity turn. Below it's shown without the fairing. 

Any tips how to stabilize large fairings? Or perhaps a confirmation that this fairing is just too large for the poor game engine? All comments are welcome.

[Streetwind]

22 hours ago, Magzimum said:

Any tips how to stabilize large fairings? Or perhaps a confirmation that this fairing is just too large for the poor game engine?

Neither/nor. This isn't a fairing issue. This is a payload issue. The thing you are trying to launch just isn't stable enough. The game borks out on you not because there's a fairing, but because the thing inside the fairing is clipping through it as it wobbles, causing all sorts of unintended effects.

You might not like it, but you'll have to redesign that craft. The easiest solution I can see is splitting it in two: you launch the main craft first, with a docking port in place where the wing cluster should connect. Then you launch the wing cluster separately and dock it in Kerbin orbit.

[Tex_NL]

A few options come to mind:

1. As @Streetwind says; Launch in sections and assemble in orbit.
2. Build in orbit with a mod like ExtraPlanetaryLaunchpads.
3. Don't try to lift your entire Eve launcher. Make it lift itself! Use the engines and fuel! Then refuel in orbit.
4. Strap your launch boosters to the side instead of the bottom.
5. Only shield the most offending parts with fairings.

[paulprogart]

23 hours ago, Magzimum said:

But that thing is giving me a headache. The payload inside wobbles - it's moving from side to side already on the launchpad. Autostrut or real struts don't seem to do much. And if I strut it too much, it just explodes on the launchpad.

How did you autostrut?  I've had success stabilizing payloads in fairings by setting autostrut on some of the bottom parts inside the fairing to Heaviest.  Never on anything close to this big mind you, but it might be worth a try...

To work, the heaviest part as the game sees it needs to be on the launcher outside the fairing.  Then it will effectively create a bond from the autostrutted parts inside the fairing through to the heavy part outside.  You can see the autostruts as orange lines on a part in the VAB when toggling its autostrut mode.  (I can't remember if there's a hotkey that needs to be pressed first to turn that on, sorry.)

Of course this may be considered a cheat, depending on how pure you want to be...

[Benoit Hage]

Could it be a part clipped that causes your problem? Are you sure every heavy part (all stages) is autostrut to the heaviest? Is your root part centered on your ship (no offset)? What happens if you empty the tanks from your lander, does your rocket still wobble?