Stability between two or more crafts while docked?

[Toastedbuns]

Quick question, does anyone know of a mod that allows two ships to NOT flail around like a fish out water? Been having that problem with my mothership and her six payload.

[Darren9]

Quantum Struts Continued used to be the best way to form struts in space, now though I think Active Struts is more functional and more recently developed.

[Toastedbuns]

I'll check both of them, thanks!

[smjjames]

KAS could work, but that may require geting a kerbal on EVA.

[wasml]

Not a mod but one thing I've found helps is to turn off all but one or two central SAS modules on large collections of docked ships. The modules on opposite ends of the ship will start fighting each other otherwise. The hard part is remembering to turn them back on for pieces when you undock them.

[Streetwind]

Docking port stability is directly related to the mass of the docking port. So using the 2.5m senior docking port for everything is the immediate stock solution. The smaller docking ports are so light that they'll simply never stay stable, so don't use them unless you cannot avoid it.

Stockalike Station Parts Expansion offers several very heavy docking collar modules that should help forming more rigid docking connections. Intended for stations, obviously, but maybe it works for you.

[cicatrix]

I use KAS. Solves the problem.

[Yemo]

Active Struts, you can set the Autostrutter part up to connect as soon as you dock the vessel.

They are also KAS compatible and supported by the SETI-BalanceMod (link in my signature).