Help! 'Set as target' targets wrong docking port!?

[silvanus]

I have a fueltank with a docking port on either end - I control the craft by having a probe connected to one of the dockingports. - My issue is that when I want to dock something to the other docking port and I set it as target, the GUI then shows the first docking port as target (the one where my probe is already attached). This prevents me apparantly from doing a succesful docking to the craft. When I detach the probe and try docking to the that dockingport instead, it works fine- anybody had this issue? The docking port is correctly attached and facing the right way and I can perfectly access it in the GUI by right clicking it - I just get the wrong target when accessing it.

- - - Updated - - -

Screenshot of craft: http://imgur.com/a/7ICl9

- - - Updated - - -

Also if anyone happen to know how to edit the save file so 1 RCSblock becomes 4 symmetrical placed RCSblocks, that would be greatly appreciated. Makes docking extra interesting when you have a very heavy craft with RCS thrusters on only one side! :-)

- - - Updated - - -

Don't know if this is related to the issue but when I in the VAB try to flip the tank with the docking ports, it seems like it will only connect through the one docking port -After having attached it to the probe however, I can perfectly attach something to the problematic port. I also tried to delete the docking port and attach a new one, but doesn't make a difference :-(

http://imgur.com/O1Xy8yy,tSyIMvP#1

Edited July 14, 2015 by silvanus
screenshots added

[Snark]

I'm trying to understand what you mean by "the GUI shows the other port as the target." How can you tell? Does the nav ball show the target marker in the wrong place, or something? i.e. can you be a little more specific about what you mean by "shows"?

[silvanus]

In the screenshots in the links you can see the target market is displayed inside the opposite docking port - I would expect the green marker to be displayed inside the docking port where I select set target as. It also displays the distance to the wrong docking port for some reason

[Randazzo]

In the screenshots in the links you can see the target market is displayed inside the opposite docking port - I would expect the green marker to be displayed inside the docking port where I select set target as. It also displays the distance to the wrong docking port for some reason

That marker doesn't really mean anything for docking, and will always be in the same place on the craft regardless of what docking port you target. Whatever port you right click on and set as target is the port you have targeted.

Edited July 14, 2015 by Randazzo

[silvanus]

Okay strange, I thought you could always see the exact docking port marked. I wonder why only the other docking port worked for me then. Any ideas from looking at the screenshots?

[Coga19000]

The marker is always on the CoM of the target object. The docking port you choose as target only dictates which side will be indicated as "Target Prograde".

[FancyMouse]

That's why you need those docking alignment mods

[Venusgate]

I don't know what these folks are talking about with target staying on "CoM." That is not what i've experienced.

That said, your problem is peculiar. have you considered slapping a reaction wheel on your probe, rolling around, and seeing if your navball changes targets when you switch?

[Snark]

The marker is always on the CoM of the target object.

^^ This. That's what confused me in the initial post, I didn't realize you were trying to use that marker for docking purposes. Ignore the marker, it's not useful for short-distance work.

My issue is that when I want to dock something to the other docking port and I set it as target, the GUI then shows the first docking port as target (the one where my probe is already attached). This prevents me apparantly from doing a succesful docking to the craft.

The highlighted sentence above is the crux of the matter. How does it prevent docking? Can you describe your usual process for docking?

Just for reference, mine looks like this:

1. Rendezvous with the target (end up very close to it, at zero relative velocity).

2. Select the docking port on the target that I want to dock to, choose "Set as target".

3. Select the docking port on my craft that I want to dock from, choose "Control from here".

4. For convenience, switch briefly to the target and rotate it so that its docking port is facing directly at my ship

5. Switch back to my ship and rotate it so that it's correctly aligned (i.e. its docking port axis is parallel to the target port's axis), though it may not be quite perfectly positioned yet (i.e. could be a bit off-center).

6. Turn on RCS, press caps lock to turn on fine-control mode (because that makes RCS better, for interesting reasons that for brevity's sake I won't go into at the moment), and thrust gently prograde (i.e. towards the target), up to ~0.2 m/s.

7. If I'm off-center (i.e. if the target marker isn't perfectly centered in the crosshairs on the navball), use RCS to thrust laterally slightly to correct. The target will start drifting towards the navball center. When it gets there, I'm perfectly lined up, so thrust laterally again to kill the sideways speed and I'm heading directly towards the docking port.

8. Dock!

Note that none of the above steps involve "look at the little yellow target marker in the main window", which is why I'm curious why the placement of that marker is causing docking problems for you.

Step 5 is the only moderately tricky part, because eyeballing the alignment can be difficult. That's the place where a docking alignment indicator mod can be really helpful. My personal favorite is this one:

http://forum.kerbalspaceprogram.com/threads/54303

...it's super lightweight, has no UI to clutter up the screen, does exactly what I want it to: any time that my target is a docking port, it just adds a little red icon to the navball indicating the proper alignment. With this mod, step 5 is trivially simple: just rotate my craft so that the red icon is centered in the navball cross-hairs.

Edited July 15, 2015 by Snark

[Sharpy]

...OTOH yesterday I experienced an annoying bug. The navball mark for the target port was about two meters to the side. Perfectly aligned and driving at the mark I'd miss the port completely.

Still, "unset target","set as target" again fixed the problem.

Most likely cause is flexibility of the target craft and KSP not updating the port position as the target *bends*. That thing is seriously like 500m long, and a meter or two of off-center bend at the end is nothing unusual.

Edited July 15, 2015 by Sharpy

[Requia]

My thought given the 'what is actually being shown' question above is to install navball docking indicator.

If you haven't yet restarted KSP also just flat out try that a lot of weird behavior goes away after a reboot, Squad got really good at sanitizing the kraken from save files, and this fixed one of my own docking nightmares.

[Laie]

I just leave this here: http://forum.kerbalspaceprogram.com/threads/86086-docking-woes-navball-parallax-error/page2