What changed in aerodynamics or ship config?

[Targa]

Hey all. I haven't played KSP since some time last year. I know a lot has changed since then, such as heat reentry damage, etc. But my main problem/concern at the moment is "what has changed in spacecraft aerodynamics"?

Example: In the old version of the game, I could add a couple of small fuel tanks to the starting (manned) capsule, add an engine, add a couple of radial decouplers with small solid rocket boosters attached. Launch the ship and steer across Kerbin using WASDQE. No issues with being able to keep the craft flying in the direction I want to go. In the latest version of the game, building this same craft, or just about any other craft design, 100% of the time the ship will lose control shortly after takeoff and start uncontrolled spinning end-over-end. It's as if the reaction wheels or SAS have been severely weakened...

Does anyone know or remember what the change was when this started happening? Because I'd like to modify it out of my game.

Edit: Well, I don't see a way to delete the thread, so I'll just post here that I found part of the answer here:

http://forum.kerbalspaceprogram.com/threads/120512-Spinning-Rocket-Error-Problem

Apparently the whole aerodynamics model of the game has changed... If I even tip my rocket slightly off from going straight up, it starts spinning end-over-end. Anyone know how to mod this new behavior out of the game?

Edited July 2, 2015 by Targa

[Marz]

Apparently the whole aerodynamics model of the game has changed... If I even tip my rocket slightly off from going straight up, it starts spinning end-over-end. Anyone know how to mod this new behavior out of the game?

Frankly, it's already in the game. You should limit your thrusters. You can change the throttle of solid boosters. If you are going too fast, and try to turn (I think) your center of gravity is too high and its like trying to push a truck with a rope, it just won't work. Slow down and that center of gravity will be a little further down and much more manageable. You won't go as fast as quickly, but you'll still get there in the end. You can also just mass solid boosters together, it works really well but you can't turn at all. Not quite as fun but if you just need to get out of the atmosphere it works.

Its not quite like it was but 1.02 is a better version IMO. 1.04 changed a lot with atmospheric density\pressure. I don't know the exact numbers but it's significant, very significant. There might be mods that change it back, I don't know. I haven't looked.

[Targa]

Well, through Steam I was able to downgrade to "Previous stable version", which gave me 0.9 beta. I'll give that a try and see how I like it. Really not enjoying the finicky aerodynamics of 1.04.

[Harry Rhodan]

Really not enjoying the finicky aerodynamics of 1.04.

You just have to accept that the previous versions taught some pretty bad lessons in rocket engineering. The thread you linked above is a good example of that: extremely overpowered pancake lifters with countless little edges and surfaces on the top for the aerodynamic forces to attack. Or in short: it didn't even look remotely like a real rocket. There are countless threads about designing rockets post 1.0 in the turorial section in the forum and the main rules are pretty simple: draggy bits at the bottom (fins) and heavy bits at the top (an upper stage with enough juice) while keeping your starting TWR somewhere between 1.5 and 1.7. Your decription of your rocket sounds as if it would become too fast too soon while draining the tank of its single liquid stage will make the Center of Mass drop to the point where the leverage for the aerodynamic forces at the top will overpower the forces you use to keep the rocket stable.