RCS Balancing On Lifting Body Shapes

[NeoMorph]

Seriously, I spend 90% of my time trying to get the RCS balanced on large lifting bodies because the editing rotation is so freaking gross (gross in the "large amount" as well as how inaccurate it is).

For example, just moving it a teeeeeeny tiny amount and it jumps the angle of the RCS pod several degrees... and the position I need to place the damned pod is somewhere in the middle. Even using the Shift- modifier doesn't give you enough accuracy.

Consequently the poor positioning means it makes docking a LOT harder than it needs to be. I can do it, yes... BUT, when translating you don't want your ass swinging all over the place causing you to become off axis for a solid dock.

For cylinder shaped vehicles it's simple because you can place pods in pairs to offset and balance but with a lifting body if you try placing in pairs the balance will be WAY off. You need to be able to fine tune the placement but the accuracy of placing is too damned finicky. Imagine trying to place RCS on Thunderbird 2 for example.

So a lot of my time is spent swearing at the game when all it needs is a precision mode for placing parts. I'm hoping there is a way to do it that I haven't figured out yet. Anyone got any pointers?

Why the RCS isn't auto-balancing to counter the poor positioning problems inherent in KSP is beyond me... If you want to translate up it should know not to rotate you. If your ship is out of balance it should reduce power to the ones that are pushing you out of alignmenent. If the ship is TOO out of alignment it shouldn't even fire the RCS at all, giving you an idea that you need to redesign.

Edited June 9, 2015 by NeoMorph

[Rhomphaia]

RCS build aid is your friend.

The rotation tools are great for positioning RCS thrusters if you turn off angle snap. and the single directional thrusters are a help for non cylindrical bodies.

[Warzouz]

Hmm, sorry but I don't understand. By "Lifting boddies", do you refer to MK2 space plane parts ? So I undertand you have a hard time placing your RCS parts on your space plane ?

If I understood correctly, on my space plane I use only 2 RCS blocks right over the CoM. One on top and one at the bottom of the plane. Then I use 4 "place it anywhere" inline RCS. 2 on the top and 2 on the bottom at the same distance from the CoM.

My CoM doesn't move a lot from full to empty so I don't drift a lot while docking. Further more, drifting is not a big deal. While you drift in one direction as you accelerate you'll drift back while decelerate.

[NeoMorph]

Nope... not the MK2... I was trying to use the RCS Build tool (which I use a lot) on the Mk4 space plane parts. I found I was fine on up/down/left and right but when you add anything that gives you forward and back it totally messes up the torque on everything else.

I've been balancing normal rockets for a LONG time now and can do it pretty much in my sleep but when you get something like the MK4 it totally falls down and shows the problems with the placement alignment.

Thinking about it, what would be really useful is placing rcs (or even any engine) at a specific angle that you type in... then any pod you place will fire in that direction allowing you to more easily balance the placement. You see the problem comes from when the engine connects to the model surface... it can twist the angle to something weird which makes it REALLY hard to get the balance right. The only way you can get around that is to use SAS to keep correcting the poor balance which isn't exactly good design. Add in possible phantom forces and docking gets to be crazy hard.

Oh and Warzouz... on small to medium ships, drifting isn't much of a problem. On medium to large ships it's a right pain in the ass.... make the craft large and asymetric and you get problems that need more precise placements... oh and if you don't know what a lifting body then you really need to bone up on space tech.

http://en.wikipedia.org/wiki/Lifting_body

TLDR: Basically the problem I'm having is balancing RCS on large asymetric shapes even using RCS Build Tool.

P.s. I even wrote up a standard balancing tutorial on here for those who have probs balancing RCS so I'm not exactly a newbie. http://forum.kerbalspaceprogram.com/threads/28983-How-To-Balance-RCS-On-Your-Payload

[Red Iron Crown]

You might find Padishar's Part Angle Display to be helpful for more precise rotation of your RCS ports. I've also found it advantageous to use linear ports instead of the quad blocks for spaceplane RCS, makes it easier to tune one axis at a time without affecting the others at the cost of a slightly higher part count.

[Feradose]

Okay try turning off the angle snap and use the gizmos on "local" mode by pressing F, it should help placement a great deal, you might still have to rotate it too

[NeoMorph]

You might find Padishar's Part Angle Display to be helpful for more precise rotation of your RCS ports. I've also found it advantageous to use linear ports instead of the quad blocks for spaceplane RCS, makes it easier to tune one axis at a time without affecting the others at the cost of a slightly higher part count.

It's those linear ports I use a lot (check out that tutorial I did... I have been using them for a long time.). But that Part Angle Display is something that will probably help a LOT. Trying to keep up with what angle the part has changed too when you move it a millimetre and suddenly it is pointing in some weird direction that has now messed up your balance is what was really messing my ship up. Lifting bodies look really nice but all the curved angles really make balancing a chore. Hell, I can balance a LEM faster than a lifting body heh.

Edit: YES!!!!! That Part Angle Display is just perfect for what I wanted. To be honest I'm baffled that it's not part of the main game. Being able to use fine movement down to 0.01 degrees it means you can really fine tune your setup. So thanks Red Iron Crown!

Edited June 9, 2015 by NeoMorph
Confirmed answered