she wobbles ever so slightly

[putnamto]

when i had first built this station is was basically just the science lab, with 4 gigantors connected radially and the batteries/probe cor connected inline to the top of it.

it would hold steady, not rock at all.

then i decided that i wanted to change the way the solar panels were attached, so i built an arm attached it to the bottom of the craft and mounted the gigantors on it using KAS and it started to slowly roll back and forth, since then ive moved the batteries radially and attached the crew module+rcs and its still rolling very slowly, it will go left for awhile, then go right for awhile, back and forth. i thought taht doing a quick time warp would stop this, and it did for a minute, then the ship slowly starts to wobble.

it never picks up speed or has me fearing that it will rip itself apart, but i would like to understand why its doing this, and how to correct it.

im afraid that after i start adding more modules to the station and it becomes more complex that the wobble will become more and more severe until eventually it rips itself apart. 

i love my station.

oh and a side note, when i first launched it i wasnt paying attention and it ended up with a 350km/80km orbit, after i had attached the long arm i also used a ship to push it into a circular orbit of 160km, is that why it wobbles now?

[Bakkerbaard]

One: It looks like a baster.

Two: I have a massive station halfway between the Mün and Kerbin. It wobbled every time I stuck something on it, which was especially visible in the solar array. I don't know why that is, probably because that's usually such a stretchy appendage, like those stabilizers sports archers have on their bows. Whatever it looks like, I've got control rings on my station and if I activate SAS it'll stop wobbling. I see your ring is sideways. I don't know if that makes a difference.

Oh! I also had Bill hover around the station with portable struts, to strengthen the docking ports and tanks and whatnot. I don't see alot of points on your station that have room for a strut, but you could always have a look to see if that makes any difference.

[FireKerb]

Active SAS can create wobbles. So can RCS.

Turn them both off to see if it continues wobbling.

[Snark]

13 hours ago, putnamto said:

it never picks up speed or has me fearing that it will rip itself apart, but i would like to understand why its doing this, and how to correct it.

Sounds like the SAS is having some problems "tuning" itself to your station's current configuration.  That's basically a bug:  ideally, it ought to automatically compensate for however you have your station built, and not oscillate.  However, getting that sort of thing "right" is a notoriously difficult control problem, so I'm not surprised if the code isn't handling it quite perfectly.

A couple things to try:

First, as @FireKerb suggests, try turning off SAS and see if that stops the oscillation.  The reason to do this is, you want to make sure which one of these two problems you're having:

• A physics problem.  This could happen if the craft has joints that aren't rigid enough, and/or there's something wrong with KSP's physics simulation.
• An SAS control problem.  This is the issue discussed above, in which there's nothing physically wrong with your station, but the code that controls the automatic SAS adjustment is not tuned quite right.

If the problem stops when you turn off SAS, then you have an SAS control problem.

If it keeps wiggling/wobbling with SAS turned off, then it's a physics problem.

From your description, I'm guessing it's probably an SAS issue.  One thing you could try-- not guaranteed to help, but it's worth a shot-- would be to try adjusting the torque on your reaction wheels.  By default, they're at 100% strength.  Make sure "advanced tweakables" is turned on in game options, then try going to your reaction wheels on the station and reducing their power to something other than 100% (for example, to 50%).  Depending on what's going amiss with the SAS tuning, that might solve your problem.  You could try various torque power settings to see what works well.

14 hours ago, putnamto said:

im afraid that after i start adding more modules to the station and it becomes more complex that the wobble will become more and more severe until eventually it rips itself apart.

That shouldn't be a problem-- just make sure that the stuff you add doesn't have much reaction torque available.  Either attach things with no reaction wheels on them, or set the power on the reaction wheels to be fairly low; that should keep things a bit more stabilized.  Also, when adding stuff, try to use the largest size docking ports you have available:  bigger ports are a lot stiffer and will have less wobbling.

You also have the option, when attaching parts, to tinker with auto-strut settings.  Let's say you attach a new module, and then you watch it for a bit and you see that "oh no, it starts wobbling back and forth".  In that case, just pick the most massive component on the new module you just added, and go set its autostrut setting to "Root Part".  That should "nail it in place" and keep it from waggling further.  You don't want to go overboard on autostruts, because over-using them can sometimes cause weird shaking problems of their own, but a little judicious use here and there can save you a lot of grief.

14 hours ago, putnamto said:

oh and a side note, when i first launched it i wasnt paying attention and it ended up with a 350km/80km orbit, after i had attached the long arm i also used a ship to push it into a circular orbit of 160km, is that why it wobbles now?

No, that's not a problem at all.  There's no such thing as "tidal force" in KSP, and as far as stability is concerned, your ship doesn't care what orbit it's in.  Whatever the source of your problem might be... your orbit isn't it.

[Kesa]

The main source of sustained wobbling (one initiated manually) is when your control center is far from your torque modules (and have SAS on) :

If you control your ship from the tip of a long arm, it will detect small oscillation that only affect the tip of the arm, and will try to stabilize it by using torque on the whole vessel, giving it inertia. If the vessel is big enough, the effect of the correction will take time to be felt, which leads to systemetic overreaction. For moderately size craft, like yours seems to be, it often increase the period of oscillation, so it reduces the overcorrection, and "stabilize" in a gentle wobble. But for bigger ships with especially bad configurations, SAS and wobbling can reasonnate and be in opposition of phase, leading to an over increasing wobble and eventually the self dissassembly of the station.

 

There might be other causes of minor wobbling, generally not as dramatic as the one explained above.

 

Solution :

1. Control the station from a part as close as possible to its center of mass. That part, whose orientation is used by the SAS, is less likely to oscilate randomly and thus reflects more accurately the rotation of the station as a whole.
2. Move reaction wheels close to the center, and desactivate those that are far from the center.
   That way, your torque parts actually contribute to the rotation of the craft, rather than to its wobbling.
   Likely, you probably want to desactivate RCS thruster from a ship docking to your station. (Allocate a action group to toggle attitude control of your vessels). RCS thrusters are more efficient far from the center though, so next advice is especially important for arms reaching away from your station containing them.
3. Use as few parts as possible for the skeleton of long structures. Long grider segment rather than regular ones, MK3 Bay for stations whose sole purposes is to be big... Use struts (auto struts).
4. If all else fails, desactivate SAS, and use time warp to stabilize when needed.

 

From the picture you gave, 1. and maybe should suffice to solve your issue.

[ArmoredLipid]

Switch SAS to "pilot only" mode. It will only orient your station, not attempt to keep it facing in a certain direction.