I need help for building crafts!

[T-20000]

So,  when I was trying to build a mega rocket that could bring the entire Duna complex to LKO, but the rocket is very unstable even with lots of struts (The strut actually broken when the vehicle is still on the pad) So I need some help.

[Wizard Kerbal]

Could you share a picture if the craft? That could help diagnose the problem

[T-20000]

 

13 hours ago, The wizard of me said:

Could you share a picture if the craft? That could help diagnose the problem

Okay here it is

[Vanamonde]

Your thread has been moved to Gameplay since you're seeking help rather than offering it. 

And on that subject, where is the craft failing? It looks sensibly built and sturdy enough to me, though you appear to be launching retrograde for some reason. Try flying it until it fails, then bring up the report with F3 and please screenshot that for us. 

[Wizard Kerbal]

2 hours ago, T-20000 said:

 

Okay here it is

That happened to me a lot! The command pod begins to sway back and forth until the kraken devours it. My solution was to strut up the payload, then using interstage nodes, put a stack separator between the payload and CSM, if you are going to dock with it.

[king of nowhere]

autostrut the payload, that's the apparent problem

[Wizard Kerbal]

4 hours ago, king of nowhere said:

autostrut the payload, that's the apparent problem

Autostrut is kraken bait my friend

[king of nowhere]

5 hours ago, The wizard of me said:

Autostrut is kraken bait my friend

no more than anything else. and on a large ship, it is less troublesome than anything else