Change root and subassemblies

[nohelmet]

I'm trying to get a subassembly to work, without success.

What I'd like to make:

a tiny rocket with an external seat and a docking port. Then my plan is to make some bigger ship or base with a docking port, grab this subassembly, and voila! My kerbals can go on little side trips.

How I've done it:

I've made the little rocket, then used the "change root" tool to make the central fuel tank the root. Then it asks me to click on a second thing and I click on the docking port.

Where it breaks:

I grab this subassembly and plop it on top of, say, a docking port on a fuel tank. It attaches fine but then in flight when I right-click on the port I only get the option to "control from here". What I'd really like is the option to decouple.

I also tried selecting the docking port first and then the tank, and when I do that it tells me that "the selected part is not attachable" and I can't save it as an assembly.

What should I do?

Edited January 25, 2015 by nohelmet

[bakanando]

Have you tried creating a dummy ship, add a docking port to it, add the port for the mini-ship, then build the ship from there, finally grab your ship's docking port and save as subassembly (without changing root part)? I remember I had to do some similar hack to radially attach a subassembly.

I hope it works.

[Laie]

I grab this subassembly and plop it on top of, say, a docking port on a fuel tank. It attaches fine but then in flight when I right-click on the port I only get the option to "control from here". What I'd really like is the option to decouple.

It may sound silly, but.... have you tried the other port, the one it's attached to? I find that of any two connected ports, only one can be made to decouple/undock.

[Red Iron Crown]

(Obligatory request for a picture of the craft)

It's worth pointing out that two docking nodes aren't necessary for decoupling, one will do. The second is only required if you intend to reattach at some point after decoupling.

[nohelmet]

What should I do?

OK friends, thank you very much for the answers!

You've motivated me to give it another look, and I think I figured it out.

The problem wasn't actually the subassembly stuff, it was that docking ports are very picky. Just placing them on top of each other isn't enough - you have to place it with the green spheres touching. So you have to look sideways as you do it, or it won't work!

Due to the geometry of my rocket, looking at things sideways was difficult. I managed to move the camera so I could get the docking ports to "snap", and all is well!

Thank you! I hope that docking port finickiness is fixed in the release version!

[Laie]

Check the key bindings. There's a meta key (left ALT in windows) that modifies some actions. In vehicle assembly, holding down meta while placing a part will disable surface attachment. That function would have saved you a lot of twisting and squinting just now.

[nohelmet]

In vehicle assembly, holding down meta while placing a part will disable surface attachment.

OOOOh my, yes, that will help so much! Thank you!