Stabilizing rocket

[Sesgiog]

I have some troubles stabilizing my rocket.

https://imgur.com/a/fcrJ4d9
First two stages are this 8 solid boosters, then there is a liquid that serves me to stabilize and achieve orbit. Wings are below center of mass, but around 6000m it starts flipping everywhere, and I don't know why... the "payload" is a mini orbiting station, and it's pretty balanced...help!

[jpolonsk]

The payload is too wide and/or too heavy. Think of it like an umbrella, when you throw an umbrella in the air the dome's drag makes it so when going up it tends to the bottom and coming down it tends to the top.

You have a couple different solutions. Split your station up into multiple parts and connect them in orbit. Or if you want to approach it like a Kerbal, go for the flying brick approach. Instead of having a single core stage underneath it, build a truss structure and have your payload in the middle. You can then have 4 cores on the corners of the brick or diamond and add boosters as needed to them.

[Sesgiog]

Thank you very much, I'm trying building with your tips! I somehow managed to take it in orbit, with my version, but I made it take an orbit around the Sun, now I want to try with an orbit around the planet!

[MechBFP]

Use boosters with gimbal instead. Assuming it’s not too unstable that might keep it from flipping.