Stop wobbling of large ships constructed in orbit

[Kev1n8088]

I'm currently building a colony ship to go to Duna. Unloaded, it should weigh in at a tad over 1400 tons and is around the length of the SPH. Due to this, when I'm rotating the ship, no matter with RCS or with reaction wheels, the entire ship flexes. Strutting helps, but as it's constructed in orbit, I can't strut different segments together. The segments aren't connected via docking ports, I'm using the construction port from USI to weld parts together. My reaction wheels are concentrated in one area, and I can't change that as I have a specific model to go after. Is there a way to stop this wobbling? I haven't dared to perform a manuever, it'll probably shake itself apart. 

[OHara]

11 minutes ago, Kev1n8088 said:

My reaction wheels are concentrated in one area, and I can't change that as I have a specific model to go after. Is there a way to stop this wobbling?

The most satisfying way, when it works, is to select the probe core closest to those reaction wheels as the 'control-from-here' part.  That avoids the real-life feedback oscillations, that you get when your rotation-sensor (probe core) is wobbling in a direction opposite to your rotation-actuator (reaction wheels).

If USI or other mods you like include a way to send a Kerbal on EVA to connect struts, that is also satisfying.

Failing that, there are autostruts, available if you enable them in one of the settings or cheat menus.  They can be frustrating because they are invisible unless you select 'visualize autostruts' from the cheat menu, and sometimes cause their own faster-frequency wobbling that does not seem to correspond to any real-life effect.

[Vanamonde]

Welcome to the forum. I have moved your question to the gameplay subforum. 

As a suggestion, how about turning on "fine control" with the capslock key? This would apply less force when you rotate and might help. Not a full solution, though. 

[Pyro_doughnut]

I found that turning off stability assist got me through the ascent out of kerbin's atmosphere as the ship stopped trying to correct itself and thus wobbling...

But as above not a full solution because you would need to turn sas back on when in orbit

[Kev1n8088]

On 3/6/2020 at 10:40 AM, OHara said:

The most satisfying way, when it works, is to select the probe core closest to those reaction wheels as the 'control-from-here' part.  That avoids the real-life feedback oscillations, that you get when your rotation-sensor (probe core) is wobbling in a direction opposite to your rotation-actuator (reaction wheels).

If USI or other mods you like include a way to send a Kerbal on EVA to connect struts, that is also satisfying.

 

That actually makes sense! I tried that and it worked. Did a slow thrust and there was virtually no wobbling.

[DeadJohn]

Kerbal Joint Reinforcement mod. Pick from the original, "Continued", or "Next" forks depending on which KSP version you use.