Docking port configuration for very large ships

[Fractal_UK]

Hi all,

I've been attempting to build a large battlecruiser capable of undertaking a five year mission to explore new worlds in the Kerbol system. After hours of effort I've managed to launch this:

I'm reasonably happy with the appearance of the thing and its functionality - even if it doesn't have any landers yet but the triple docking point arrangement (tri-stack couplers with three docking ports attached), which I implemented to try and ensure a secure coupling between modules doesn't really work as intended. I can't manoeuvre the ship rotationally under RCS without inducing horrendous oscillations which look like they're going to tear it apart. It's fine without RCS but the part count is so high that the lag, even with my pretty powerful machine, makes such manoeuvres painstakingly slow. I'm sure plenty of people here have constructed similarly large ships in orbit, so could anyone suggest a better docking configuration for future constructions that might help alleviate such problems?

[aesclepius]

On my mobile, so can't provide pictures, but I've had a lot of success with using an x-shaped system with a port at the centre and one on the end of each line.

O O

\ /

O

/ \

O O

Make sure all ports are aligned horizontally and just flip upside down for the other end of the dock. Poorly explained I know, but I'll try to get pics up later.

It makes for a very stable docking collar even under hefty acceleration.

Edited April 28, 2013 by aesclepius

[aesclepius]

Double posted

Edited April 28, 2013 by aesclepius
Double posted

[Tex_NL]

Even X shaped couplers will eventually wobble just as tri-couplers as there will only be one main connection. Best solution to eliminate wobble is struts. Both 'Docking Strut' and 'Quantum Strut' do that job nicely.

[shand]

hey there Aesclepius' slave here.

here are the promised screenshots explaining!

here we are in the VAB. I've chosen to use a 2.5m tank in the centre and 1.25m parts on the outside. other configurations are fine.

Now we are in orbit (yay hyperedit), approaching a sister coupler of the same configuration (yay Deadbeefs subassembly mod):

And finally, fully docked and secure. all 5 ports dock. you can also do this in the VAB, you need to have 1 primary node, the others you place near each other and they join on physics load. LOVELY!

EDIT: actually they are pretty secure, definately up to the job. not 100% solid but definately enough to stop any wobble thats worth writing home about. plus its 100% stock (if you choose to not use any stock parts)

[Temstar]

This is the method I use:

Just download the craft files at http://forum.kerbalspaceprogram.com/showthread.php/24990-0-19-1-Orbital-Propellant-Depot-Olympus-II and save the part as your own subassembly

Seems pretty strong: