RCS some thrusters not working!? (plz help quick)

[Heroshrine]

Why are the top rcs thrusters not working (in photo)?? They are not attatched to a service bay, and where never inside a payload of any kind. (sry for bad photo, i am tumbling through space away from where I am trying to dock so i was in a rush).

I waisted so much fuel trying to not spin and tilt out of controll before i realised they weren't working. I turned on infinite fuel, and it STILL doesn't work!! plz help. I'm trying to dock on career and I don't have quicksaves or reverts on, and kerbals don't recover.

 

Edited September 10, 2018 by Heroshrine

[Zhetaan]

@Heroshrine:

I suspect that you're seeing the intersection of two separate problems:  fine control and an imbalanced vessel.  Bugs are always a possibility as well.

It's not a lot to go on, but I notice that you have fine control turned on (the pointers for roll, yaw, and pitch in the lower left corner are blue instead of their normal orange:  it's toggled with the Caps Lock key).  With fine control on, the craft tries to counter any imbalances in the mass and placement of RCS thrusters, which can result in some thrusters appearing not to fire.  In actuality, they are firing at extremely low throttle, but there's no easy way to see that.

With a full fuel tank and presumably an occupied command pod at one end, and an almost-empty monopropellant tank and hollow structural piece at the other end, you're definitely imbalanced.

Do the thrusters work when you roll?  Your vessel should be balanced on the axis, so there would be no throttling for that.  Alternatively, do they work after you press the Caps Lock key?

Failing that, you might want to right-click on the thrusters themselves and check their context menus.

Edited September 10, 2018 by Zhetaan

[Heroshrine]

15 minutes ago, Zhetaan said:

@Heroshrine:

I suspect that you're seeing the intersection of two separate problems:  fine control and an imbalanced vessel.  Bugs are always a possibility as well.

It's not a lot to go on, but I notice that you have fine control turned on (the pointers for roll, yaw, and pitch in the lower left corner are blue instead of their normal orange:  it's toggled with the Caps Lock key).  With fine control on, the craft tries to counter any imbalances in the mass and placement of RCS thrusters, which can result in some thrusters appearing not to fire.  In actuality, they are firing at extremely low throttle, but there's no easy way to see that.

With a full fuel tank and presumably an occupied command pod at one end, and an almost-empty monopropellant tank and hollow structural piece at the other end, you're definitely imbalanced.

Do the thrusters work when you roll?  Your vessel should be balanced on the axis, so there would be no throttling for that.  Alternatively, do they work after you press the Caps Lock key?

Failing that, you might want to right-click on the thrusters themselves and check their context menus.

I had to cheat to dock. They where not working AT ALL, even with fine control turned off. Not even for rolling. Its probably a bug, but idk what wold cause it.

[Rocket In My Pocket]

The pic is so dark I can't really tell but are they 2 groups of 2 or 2 groups of 4?

Because if they are just 2 groups of 2 than you lack lateral thrust, and won't be able to "side step."

Your control point could also be the issue, making the controls and response not what you expect.

[Zhetaan]

10 minutes ago, Rocket In My Pocket said:

The pic is so dark I can't really tell but are they 2 groups of 2 or 2 groups of 4?

It's two groups of four.  They ought to be working.

@Heroshrine:

I think it's a bug, but just to cover everything (that I can think of), did the upper thrusters sink into the tapered piece when you placed then in the VAB, such that you had to pull them out again with the offset tool?  It's possible that placing them on the very edge caused them to think they are clipped into the part and thus occluded.  I think that throws a message on the right-click menu, but I am not certain.  Either way, if it's not a bug, and it's not a control issue, then a placement issue would affect all four thusters at the same time (but not also affect the other four lower down).

Perhaps @bewing knows.  He's far more knowledgeable about the inner workings of the code, and might be able to say whether this is an edge-case occlusion issue.

[bewing]

Nope. Never seen anything like that before. I rarely use RCS myself. Would need a craft file to test.

[swjr-swis]

35 minutes ago, Zhetaan said:

It's possible that placing them on the very edge caused them to think they are clipped into the part and thus occluded.

This only happens with bays and fairings, which is not the case here. No other parts will 'occlude' anything, as the game code treats any other part clipping as if the parts are fully exposed to space.

[Gargamel]

2 hours ago, swjr-swis said:

This only happens with bays and fairings, which is not the case here. No other parts will 'occlude' anything, as the game code treats any other part clipping as if the parts are fully exposed to space.

Prove me wrong here, but I'm not so sure on this.  I have had RCS thrusters blocked by some other item (like a solar panel or large battery) reduce the effectiveness of that thruster.   We also had a recent thread were a player had grabbed an asteroid, and was using radial engines to try and pull it, but the engines were close enough that they were pushing against the asteroid. 

Now, that is not the case here, as I could always see the RCS firing, but it just wasn't doing anything, as it was pushing against another part of the ship.   The RCS blocks weren't clipping either, they were just poorly placed. 

[bewing]

Engines can be occluded, but RCS thrusters can't. They are always supposed to work, even if they are buried deep inside something else.

 

Edited September 10, 2018 by bewing

[Vanamonde]

Can you right-click on the thruster clusters and turn them on? I don't know why they might be off, but it could get them working and serve as a clue to the cause. 

[Heroshrine]

@Vanamonde they are on. but its too late now, it was a while ago and i just cheated to get it into place. Oh, and btw it definitely was a glitch cus i re-launched later to test it and it was working.