Is it just me or KSP is unplayable?

[RockyTV]

I've recently got my hands on the new 0.90 version. And now I've found out that there's stuff that makes you tied to the career mode. So, I gave it a try, why not?

But, however, when I was going to do one of those survey missions, my craft seemed to randomly start to rotate around (not spin), and then, go back to the direction I was headed.

Tell me, is this because Jeb is the pilot, or because KSP physics has changed? I've ragequit because of that... I can't play.

[RockyTV]

Video

http://youtu.be/JuWiKZ9a2BY

As you can notice, when I start controlling my vessel, it becomes unresponsive.

[Norpo]

Weird...

I honestly have no idea what caused this, the yaw pitch and roll things seem not to be moving either...

Electric charge seems to be fine...

You have a pilot in there...

I dunno, sorry.

[Ival70]

That is rather strange. What version of KSP are you using? I know that the 64x version has been having some issues, though this is the first time I've heard of what you are describing. I think more information is needed. Along what axis was the craft turning? What skill level was Jeb? what were you doing, and where was your craft when this happened? Have you been able to repeat this? Did any errors appear in the logs? Were you using any mods?

Edit: Ninja'd, Watched the video. It would appear that SAS turns off when the craft turns, have you checked that?

[capi3101]

What engine are you using, the LV-T30 or the LV-T45? The T45 has thrust vectoring (i.e. ability to steer); the T30 doesn't.

Only thing I can think of off the top of my head.

EDIT: Didn't bother to check SAS. Might look to see if that's on and stays on too.

[RockyTV]

That is rather strange. What version of KSP are you using? I know that the 64x version has been having some issues, though this is the first time I've heard of what you are describing. I think more information is needed. Along what axis was the craft turning? What skill level was Jeb? what were you doing, and where was your craft when this happened? Have you been able to repeat this? Did any errors appear in the logs? Were you using any mods?

Edit: Ninja'd, Watched the video. It would appear that SAS turns off when the craft turns, have you checked that?

x32. and yes I did.

[Cerberus738]

You might need some stabilizing fins/control surfaces or more reaction wheels. Girders are deceivingly heavy maybe they are enough to drag the bottom down as your fuel empties.

EDIT: Also yes. any mods installed?

SECOND EDIT: My joystick also breaks SAS all the time. All i have to do is roll it around a little and the problem goes away.

Edited December 16, 2014 by Cerberus738
EDIT

[RockyTV]

You might need some stabilizing fins/control surfaces or more reaction wheels. Girders are deceivingly heavy maybe they are enough to drag the bottom down as your fuel empties.

EDIT: Also yes. any mods installed?

no. stock only

[WanderingKid]

SAS was turned off for the majority of your video, even though you flipped it on at the beginning. I have no idea why.

If you have them, the control surface fins (second set you get) at the bottom would help with stability.

Otherwise, I have no idea. I'm able to drive just fine... I'd seriously consider a reinstall if nothing seems to work.

[thereaverofdarkness]

It's aerodynamics. You've got to give the craft fins or wings at the base to place its center of lift behind its center of mass, if you want it to fly straight. It needs pivotal fins (like the AV-R8) or an LV-T45 or other engine with thrust vectoring if you want to turn easily. SAS and RCS aren't very good for turning in atmosphere but they can get the job done, too. You could just add a reaction wheel under the pod. The command pod Mk 1 only gets 5 units of torque, and your rocket is too big and imbalanced for 5 units to handle the force of the wind buffeting that thing in low atmosphere.

[Taki117]

Others have hit around the mark, but I don't think anyone has hit it dead on. What's happening is that your angle of attack is very large, meaning that the airflow over your rocket is more on the side than it is on the top of your rocket, meaning you are trying to fly a large board into the wind, instead of turning it sideways so that the thin part is into the wind. This increased drag is overcoming your SAS ability to compensate, and causing your rocket to flip.

[Ival70]

I think you hit this on the head, Taki. I replicated the rocket and launch profile in the video, and found it would flip if I increased the angle of attack excessively at high speeds.

[morscience]

I'm just going to go ahead and guess that the craft was built without the center of lift and mass being relativly equal. Also, more control surfaces and struts or even SAS would help, but unless you build it properly its not going to work.

[Overfloater]

While your fuel empties, the center of weight moves behind the center of drag, because there's no weight on top of your rocket. That's what causes loss of control in atmosphere.

Multi stage rockets don't have this issue because the center of mass moves to the front - towards the upper stage.

Unfortunately there isn't a tool in KSP that shows the center of drag... unless your craft is made of wings. (then it's center of lift)

If you're gonna use this design anyway, I suggest disabling fuel flow from the uppermost fuel tank, until that's the only fuel left.

And yeah watch your angle of attack, don't make such aggressive turns. Especially with the non-gimballing LV-T30 which can't counteract the spin.