Unknown torque and unbalance in simple craft?

[wilconquer]

Here is my very simple, early career mode probe:

http://imgur.com/gallery/rpI5R/new

The strangest thing happens when I fired up that engine; the whole thing wants to start spinning, VERY hard. It's such a strong spin that I can't stop it even if I lean on the controls to prevent it. This is with SAS enabled and the engine's own gimballing.

Now, through a bit of trial I've found that it's the probe core's own torque wheel seems to be causing it. When I turn off the wheel it doesn't spin like that. On the other hand it renders the probe unable to turn when the engine is off, so it makes orbital maneuvers hard.

I think I have also noticed this with other craft since the release of 1.0.4. Has anyone else seen this?? For reference, I only use a few mods (FAR, EngineerRedux) so I don't think those are the problem.

Edited June 25, 2015 by wilconquer

[Warzouz]

Have you used the "offset" feature ?

I had this problem ona plane where I offset a part. I editied the part and simply moved (without offset) to the location I wanted). Torque was gone. It was a very light torque though

[tutike2000]

Install Kerbal Engineer, it should tell you what the current engine torque is.

I've often seen non-zero torque from very simple craft (pod + tank + engine), no idea why.

[wilconquer]

I had never thought the offset would do this. Now I feel compelled to recheck how I set parts.

@tutike , how do I check engine torque? I don't think it's the engine, but where in engineer do I find that?

[cephalo]

You don't have any extra reaction wheels do you? I have seen that too much reaction wheel on very small craft can make the SAS not handle it well.

[rofltehcat]

I've had something like this when my capsule was (for whatever reason) rotated 5° or so. Maybe you have a very slight inconsistency in the design. Other than that maybe going back to the space center fixes it... I find that forcing a reload this way sometimes fixes strange issues.

[sal_vager]

Hi wilconquer, can you disable FAR flight assist please.

[tutike2000]

@tutike , how do I check engine torque? I don't think it's the engine, but where in engineer do I find that?

In flight, it should be in the Vessel tab. if it's 0.something you should be fine. if it's 20-ish or more. you have a problem.

In the VAB torque will show up in the staging grid.

[wilconquer]

Ooooh disable FAR assist, I completely forgot that was a thing. Thank you! I'll try all of these suggestions ASAP.

[DancesWithSquirrels]

Also make certain you don't have any trim set - Alt-X to zero any trim.

[wilconquer]

Okay, so I have tried a few things with no success saving the craft. First, it's not FAR assists, those default to 'off' and I barely use them. Second, I have checked the Kerbal Engineer and there will be a huge torque, but only when I'm on the retrograde marker-side of my vectors. For some reason, it doesn't want to point retrograde at all (this is why I got so angry yesterday when I couldn't land a basic, teeny-tiny probe because it kept flipping around). But it seems to settle really nicely on the prograde side and will obey pointing commands with SAS on. Also, I keep hitting Option+X for resetting trim (I'm on OS X) and I think it's resetting? I'm honestly not sure.

Right now, I'm trying to remake the probe in the VAB and balance it better (grid-snap on, symmetry for all parts) and see if I can make a better probe. Thanks to all, hopefully this doesn't become a thing that makes my current save unplayable.

[wilconquer]

Okay, I'm really confused now and I keep rage quitting when I can't make simple orbital insertions. Update: I build a whole new craft, use only symmetry mode, lock to grid, double up on parts that I don't normally (two antennas to 'balance' them). I make sure that FAR assists are disabled. I have reset the trim (I can't tell if it goes, but I hit Option+X anyway). So I get to Minmus, point the thing retrograde, fire full thrust...

...and it whips around prograde like it's in the wind or something...

You know when you're reentering with a capsule and it's in a sort of locally-stable orientation? If you let go of the SAS you KNOW it'll whip around the other way? This is what's happening, only with the actual control surfaces doing it. I can see the pitch and yaw controls in the bottom left suddenly slamming down and right when I hit the Z key to go full throttle.

I have no idea! I'm going to slowing uninstall every mod (there aren't many) until this goes away. Could this be kOS doing something? I just installed it to try it out, and I never had problems with KSP before I installed kOS.

[Viatic_unicycle]

I have had the same problem with the lv-909. Right click the engine and disable gimble, works everytime for me