Navball Wobble

[Ryds]

Hi there,

I've not had this issue before but it's killing me at the moment. My ships, of all different sizes and parts, seem to wobble in orbit. It's not very visible when viewing the ship directly however once a node is placed, when using mechjeb or manually, the markers can deviate 180 degrees in a second - making it impossible to line up.

I first noticed it out near Dres and had to spend 5 hours trying to manually dock a ship. I got it in the end but man it's doing my head in!

I've it with RCS off, SAS off (both in crew modules and SAS rings) and combinations of them both on/off but no effect.

My wobbling ships at the minute are:

A large tanker (5 orange fueltank) in orbit around Kerbin with a large SAS ring and mechjeb

A tiny one man lander craft, about 20 tons, with 1 man module, mechjeb and a small SAS ring.

I just can't get these to dock in within a decent (less tan an hour) amount of time due to the inaccurate position reports on the navball.

I have no other mods, just the latest MJ and 023.5, any ideas at all what is causing the wobble?

.9

Thanks!!

[Hans Dorn]

Had the same problem with various ships. Some strategically placed struts resolved the issue.

[cantab]

Are you choosing "control from here" on suitable parts? For main engine burns it helps to have a probe core near the engines. For docking, you want to control from the docking port in question. This is especially, but not only, an issue for multi-part ships with sections docked together.

Are you going really slowly? That'll make the navbal more susceptible to jitter.

And, of course, have you tried closing and reopening the game? There are some other bugs that's been known to fix.

[mattheos]

Does it happen with your much smaller ships?

Its probably just your ship flopping around. Especially, with ships that big. The whole thing will flop around and that in turn, will make the markers on the navball jump around, and make orbit lines and maneuver nodes move all over the place. Sometimes quite a bit.

23.5 helped a ton with wobble and floppy issues, but struts might help. Struts, struts, struts. There are several old posts about where to put them and why.

[Pecan]

Several people have reported - and I have seen - many ships develop a 'wobble' in 0.23.5, where they just oscillate all the time; means the navball doesn't know which way you're pointing. For me a few times I just haven't been able to determine whether I even have an intercept at all because the orbit bounces around so much. A short touch of warp sometimes stops the wobble but not always, depends on the ship.

[Hans Dorn]

The SAS rings got wobbly with 0.23.5, especially the large one. If they're not firmly attached to the controllig pod and the heavy part of the ship, SAS does a bad job at damping oscillations.

Edited April 13, 2014 by Hans Dorn

[Vanamonde]

Could we see a picture of your ship? That often helps diagnose problems. (Also, moved to gameplay questions.)

[Ryds]

Hi All,

Thanks a lot for your replies and for moving this to the correct forum, sorry about that.

I've didn't see the posts about struts, is the rule of thumb just to place struts everywhere you can or are there key areas to look at. Perhaps you could have look at my ship and give me some advice.

Yep, they are two big ships, but if you look at the picture of the lander, that is actually quite a small one-man job and it was using the same one unattached when out by Dres that I noticed the problem. Now, I would say that the issue is obviously with the design of that ship in particular, but the tanker is also doing it as well and that's a pretty basic, if large, design.

Here's the pics: http://imgur.com/a/x3ZJb

Thanks a lot!