RCS tanks used in wrong stages

[camylarde]

Hello,

I hope someone an help me with the following problem: My heavy launcher has tendency to use up RCS from the payload despite the RCS tanks being attached into the bottom stage too. ANd I have to manually disable the top stage RCS tanks from being used, but its impractical to switch them on again at flight. Did I miss something during my design phase or is this a known bug?

Edited June 22, 2013 by camylarde
Closing the thread

[nick1236]

You might be able to setup an action group to turn them on and off.

[stupid_chris]

It's not a bug, it's just the logic on how RCS fuel is used. It will take it from all the tanks available at any given time. The only workarounds are to manually disable them or to disable fuel flow through your decouplers, but I think the later could affect your top RCS thrusters.

Action groups can't target fuel usage right now, so you really have to do it manually :l

[astropapi1]

You might be able to setup an action group to turn them on and off.

You can't toggle crossfeed capability on fuel tanks. :/

[Vanamonde]

I just let the thrusters pull from any tank they want, then transfer propellent to a sub-ship before releasing it.

[Horn Brain]

Your heavy launcher's first stage should not be using RCS for steering or stability. You should be using gimbals or (if you are using fixed engines) winglets. You'll save a lot of weight by getting rid of all that RCS hardware and fuel. Usually all you need is one mainsail on the center stack with the gimbal on and that will be plenty of steering authority. If it's wobbly you need struts, not more wobbly bits.

[SDIR]

Usually for a good ship you need at most 40 liters of RCS to get into orbit (sometimes you can live without RCS at all). And for docking you don't need anymore than 80 liters. RCS should only be used for immense ships once in orbit or for docking. Most other rockets can live without it.

[camylarde]

Thanks, answered brilliantly with all the bits.

[Sirrobert]

If you need RCS during accent, your craft is unstable

[MalfunctionM1Ke]

I have the same problem but I solved it by just closing the tanks which i want to save before lift off.