Mechjeb and ascent roll issue.

[SSSPutnik]

Using Mechjeb for ascent to orbit the following happens.

I have a large, heavy lifter. Asparagus staging.

After launch, all goes very well, excellent, no wobble at all, Navball shows I am exactly on course.

Shortly after hitting 32km altitude I get a horrible roll start, with SAS and RCS this persists, (or gets worse). This throws the rocket off course and usually I end up with what happens when you drop a bowling ball into a washing machine on spin. The system is very symmetrical.

Can anyone explain? I am guessing my CoM is sitting too high ?

Short of posting a pic, my rocket at this stage looks like this:

.......I

.....i I i and from above oOo (imagine the circles are lined up.) (dots for placekeeping).

Cheers.

Edited November 19, 2013 by SSSPutnik

[Virtualgenius]

Are you using the latest version try the 102 dev build had no problems with it

[SSSPutnik]

Yes, latest version. BTW, its not so much a roll as a gyration, nose turns to face another direction, system tries to correct, nose starts wandering all over the place.

[Wesreidau]

Are your controls by this altitude aerodynamic, SAS or RCS? Its possible you're reaching an altitude where aerodynamic controls lose effectiveness and you don't have enough RCS or SAS force to keep your attitude.

[SSSPutnik]

Well, there is bugger all atmosphere at 30km, but yes it could be an issue. I will try adding some winglets.

I think I just need to try building and launching the malfunctioning bit, correcting that, then put it back into the main rocket.

Was posting in hope of a quick answer where I could facepalm myself.

[Wesreidau]

Actually my post wasn't that you had a winglet shortage, but that you were potentially relying on them too much... add more SAS rings.