How do I stop my ships from wobbling after 120 parts.

[Jeb Coleman]

Whenever I build a rocket it starts to wobble after it is over 120 parts. Is there any way to fix this? Any help will be appreciated.

[Gaarst]

Depends on the design, some rockets are extremely stiff while others behave like noodles.

Screenshots would be helpful for a precise solutions but here are a few things you can do to reduce wobbling:

• Add struts
• Reduce gimbal on your engines
• Disable SAS (beware you'll have to stabilise the rocket yourself)
• Disable reactions wheels: less control, but also less wobble
• Avoid having reaction wheels far away from the CoM (command pods on the top of the rocket are a good example of this)
• Control the rocket from a part closer to the CoM of the rocket: the CoM doesn't wobble a lot and SAS is applied at the controlling part (not CoM), so SAS will not overcompensate for the wobbling, which would cause even more wobbling.
• Make the rocket shorter/thicker: tall and thin rocket are more wobbly
• Try to avoid linking putting light/small parts between heavier ones: the joints are usually weaker and the rocket will wobble more (especially the large reaction wheel between two tanks)
• Reduce the number of parts as much as you can. Not always possible, but often the simplest and best solution.
• If you're that desperate, install Kerbal Joint Reinforcement

Edited February 5, 2016 by Gaarst
Added stuff

[Evanitis]

I don't think it's the part count, rather just a long ship that you try to 'push'. You should 'pull' it instead.

Umm... I'd need a relevant picture to demonstrate...

Not the best one (not an actual interplanetary craft, just assorted junk docked together), but it will do.

Now if I tried to burn the mainsail engine (lower right corner), it would wobble like hell, possibly even break up. To fire the two radially attached Nerves (upper left corner) would be better because of less trust, but it's still pushing. But if I turned the same orange-tank part around and burned that way, it would be fine.. unless the engine exhaust touched the solar panels.

Also (unlike on the pic) use the bigger docking ports, those hold better.

Edited February 5, 2016 by Evanitis

[Joco223]

You can always install Kerbal Joint Reinforcement if you want. I really helps with big and wobbly ships