Spinning rockets

[Triarius]

Everything was going smoothly with mechjeb, FAR, and chatterer installed only for quite a while, and then all of a sudden this cropped up. My rockets all perform an uncommanded roll (ccw when viewed from below) as though the roll command (default key "Q") is jammed. I uninstalled the game, reinstalled it, and the problem went away for a while, but then came back. I tried unplugging the joystick, but that doesn't seem to help. This isn't related to the construction of the rockets, as it happens to all of my previously working designs. It will also make the capsule spin at maximum speed until electrical power is exhausted. Running down the battery seems to be the only thing that can save Jeb from a bad landing with this bug.

Has anyone else faced this?

[Master Tao]

It could be that you accidentally hit Alt+Q, which sets the trim that way.

Try clearing the trim with Alt+X.

[Triarius]

No joy, still spinning.

[smjjames]

Could you post up screenshots of one or more of the designs? I know you said they're working designs, but if theres a likely design problem, someone will probably spot it.

Also, did this start after updating one of them?

Editwhiletyping: Actually, I think I saw someone post an issue about phantom torque (which is causing the spinning) with command pods in FAR.

Heres an idea, you said it happened recently, right? Try rolling back to an earlier version of FAR and see if that still happens.

[Triarius]

Could you post up screenshots of one or more of the designs? I know you said they're working designs, but if theres a likely design problem, someone will probably spot it.

Also, did this start after updating one of them?

Editwhiletyping: Actually, I think I saw someone post an issue about phantom torque (which is causing the spinning) with command pods in FAR.

Heres an idea, you said it happened recently, right? Try rolling back to an earlier version of FAR and see if that still happens.

Yeah, like I said it isn't a construction problem as it happens even with nothing but a command pod. I don't think it is related to aerodynamics because the control surfaces deflect on their own, and the reaction wheels draw electricity to spin the capsule at about 600 rpm after separation. I should also mention that I have never updated FAR... I've only had the game about a month. If anything, I'd guess it has to do with mechjeb. I tried removing the mechjeb folder but the game won't work at all without it.

[mcapmare]

I'm having the same issue with rolling. I tried a number of things, from unplugging the joystick to changing part configuration to avoid any kind of clipping that could cause it. I still found no solution. As the OP mentioned, reverting back to the original game settings works for a while, then out of nowhere it starts the spinning again. There is either a bug in KSP or one of the mods. I'm definitely curious about the solution to this because this has been driving me nuts for the past 4-5 days now.

[Master Tao]

Odds are it's a mod, so you'll need to provide more information.

Start by reading the [thread=92229]How to Get Support[/thread] sticky. Provide your output log and a complete list of mods (including versions). Ideally, minimize that list to one version of one mod.

Does this issue affect all crafts or just some? If it's just some, provide simple example crafts.

[mcapmare]

OK, after some more testing, I determined that FAR is causing the spinning. I removed FAR and the rocket stopped spinning.

The design of my rocket is simple. It's a 2-stage rocket done with KW Rocketry parts, a 4-unit tank in the first stage and a 2-unit tank in the second stage. The command cube sits at the top in a fairing base and two cone fairing halves are covering it. There was also a RemoteTech antenna (offset into the tank) and MechJeb2 remote (offset into the tank). But I verified and these two are not the problem. I can't give you the craft file as I would have to attach my modified parts as well (I'm not using stock/mod parts, I've created my own parts based on KW).

Another thing I tried is launching without the fairings (only the cube on the base) and that seemed to not spin my rocket. So I'm thinking the problem is with FAR and fairings. With FAR and without fairings, there is no problem; and without FAR and with fairings, there is no problem. I'm looking into this right now.

EDIT: After some preliminary tests, it seems that FAR relies on the part title to determine if it is a fairing or not, and my part title was not using their convention. After adding my part title to it, the spinning seemed to have stopped. I will continue to test this and if the problem persists I'll post my findings. I don't want to hijack the OPs issue -- the problem could be caused by something else in their case. However, OP, if through trial an error by eliminating parts, you determine which part is giving you aero issues, take a look in FAR's Part Classification tab. That might fix your issue.

Edited February 16, 2015 by mcapmare