Am I totally misunderstanding the HubMax?

[kmb1611]

I'm about 400 hours into my KSP career, so not really a total newby and have successfully docked many many things to one another, but I'm completely flummoxed by the behavior of docking ports WRT the HubMax.  

When I launch my first station, the attached docking ports do not have the "Decouple Node" option available, after all, they're attached directly to the HubMax.  Sofar, so good.  I launch my next piece (a large solar array), and plot intercept in LKO.  Move to dock with the array going Clamp-O-Tron to Clamp-O-Tron.  As I bring the array in closer, they touch at .1 m/s with SAS off, and... nothing.  No magnetic attraction, no docking as I've done successfully many times in the past.  No amount of rotating the array seems to affect it. The only thing that seemingly changes is I now have the option to 'Decouple Node' on the docking port attached to the HubMax... huh?  If I click that, the docking port just floats out into space as if attached with a decoupler, which it isn't, leaving me a bare HubMax endpoint.  

Thinking I attached it wrong, I tweak how the Clamp-O-Tron is aligned in the VAB, and launch a second station (which is actually the one shown below, attempt #2), but it too suffers the same indignity as the first.  The array, for its part, seems to continue to have a normal functional docking port, though in fairness I'd need to throw something else up into orbit to test against.  But I feel pretty certain its the HubMax port that's the issue. 

So... bug? Am I missing something here? Do I not understand how the HubMax is supposed to work? Any thoughts on resolution or workaround to my station floating debris in space?  TIA

[Kurld]

I've used the part many times in the past to build bases (have one going now in current version) and haven't seen this. I have had all manner of buggy problems with docking ports over the years, so I'd put my bet on that being the source of the problem somehow.

Maybe you can look at the save file and see if you can tell what is different about the ports that work and the ones that don't?

 

Most of the problems I've had with ports have been due to parts clipping, back before it was something the game let you do.

[Alshain]

1 hour ago, kmb1611 said:

So... bug? Am I missing something here? Do I not understand how the HubMax is supposed to work? Any thoughts on resolution or workaround to my station floating debris in space?  TIA

Your large docking ports there are on backward.  I can't tell if the small ones are, it looks ok from the image but if that one is already decoupled it could have turned around.  So it's not docking because you are on the wrong side and it's decoupling from the hubmax because the proper side is 'docked' to the hubmax.  It has nothing specific to do with the hubmax, but improper use of the docking ports.

Other than that, I would say provide a craft file.  There is a chance that you attached the part to the dockable side and then rotated it as well.  You shouldn't do that if you did.  Hold the Mod key (Alt in windows) and make sure it attaches to the node the correct way, do not use the rotation tool to turn it around 180 degrees.

Edited August 26, 2016 by Alshain

[kmb1611]

Thanks @Alshain and @Kurld. I know the Sr. ones are on backwards (oops), but the standards should be correctly arranged.  

 

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There is a chance that you attached the part to the dockable side and then rotated it as well.  You shouldn't do that if you did.  Hold the Mod key (Alt in windows) and make sure it attaches to the node the correct way, do not use the rotation tool to turn it around 180 degrees.

BINGO.  That's exactly what I did, they weren't attaching properly to the HubMax otherwise!  Holding the mod key and maneuvering will avoid that issue? TY!!

[Alshain]

1 hour ago, kmb1611 said:

Thanks @Alshain and @Kurld. I know the Sr. ones are on backwards (oops), but the standards should be correctly arranged.  

 

BINGO.  That's exactly what I did, they weren't attaching properly to the HubMax otherwise!  Holding the mod key and maneuvering will avoid that issue? TY!!

Holding the mod key forces the part to snap to the nearest node rather than attempting to attach radially.  It makes things easier.  If it doesn't work, try rotating it before you attach it using the WSADQE keys.  I've also found it helps to adjust your viewing angle so you are looking at the hubmax from the side rather than head on to the attachment point.  For some reason that makes it attach better.

You have to understand that once it is attached, the game considered it always attached at that point, even if you move it (with the move tool, you can pick it up and replace it) or rotate it.  So if you attach it to the docking side of the port and rotate it 180 degrees, the game still considers it attached to the docking side of the port.  It doesn't attempt to change attachment nodes.

And don't forget the Sr. ports, those are just outright backward in your screenshot.  The texture you see there is meant to represent an airlock hatch from the inside.  You will see that on many parts (including the hubmax), sadly they are decorative only and do not function in any way.

Edited August 26, 2016 by Alshain

[kmb1611]

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 So if you attach it to the docking side of the port and rotate it 180 degrees, the game still considers it attached to the docking side of the port.  It doesn't attempt to change attachment nodes.

Yeah, that's the revelation for me, really really helpful, thank you for the detailed explanation.  (and yes, swapped the Sr.s - I play career-only, so just unlocked them not-so-long-ago )