A question about sub-assemblies and what defines a sub-assembly

[Major SNAFU]

Hi all,

Relatively ly new player with 1.0.4

I made a sort of micro probe and I then wanted to save it as a sub assembly and then pull it into other design. But when I drag the item onto the subassembly hot spot nothing happens. The probe is unmanned a has pass successful tests for flight.

So what defines a valid sub assembly? Does it have to be something with out a probe core or control pod?

Is there another way to bring smaller assemblies into a existing design. Or do I have to rebuild the probe every time I want to put it on a ship?

[LordFerret]

I believe the problem is that you're trying to drop the 'root' part into sub-assemblies, and that's not permitted. There is a way around this. Whatever it is you're planning on making a sub-assembly, make sure it doesn't contain the root and that it connects to something. For example:

This ship, cannot be dropped into sub-assemblies...

When you try to do so, it will tell you why...

Taking the same ship, removing the chute, and installing a probe core in its place - and then making that probe core the root, then selecting all but the probe core...

...that can be dropped in as a sub-assembly.

[Alshain]

Looks like this was an accidental double post but I wanted to respond to Lord Ferret to avoid confusion. You can drop a root part in a sub assembly as long as it has a stack attachment node free on the part your mouse is holding. In your example (assuming the Mk1 pod is the root) take the parachute or probe off and then drop it in sub assemblies, it will work, even if the pod remains root. Think of it this way, when you pull a subassembly OUT of storage, what do you attach it to? It has to have a node.

Edited August 13, 2015 by Alshain

[Moach]

probably nobody's fault... but I think this got double-posted

sorry for any inconveniences, but I moved an arbitrarily chosen (closer to mouse click) one of the twain and killed it very much dead... (not really, it's in the "fault-vault")

carry on, please...

nothing to see here.... keep moving... keep going... attaboy...

[Superfluous J]

And to clarify on the clarification, while you CAN have a mk1 pod as your sub-assembly root, you probably don't want it to be. Generally if you have a probe or lander as a sub-assembly, you are going to want to attach it to something from the bottom, which is likely the engine.

If you hit the number "4" on your keyboard, you'll go into "select the root part" mode. Then click your ship anywhere, then click the part that you're going to want to eventually want to stick to other things. That part is now the root part. Hit "1" on your keyboard to back into "normal" mode, click the part that is now the root, and drop it on the sub-assembly box. Now you've got a probe that, when you want to sick it to your mothership/lifter/whatever, will sick on the way you intended it to.

[Sharpy]

In this particular case, the most reasonable approach is to have the whole vessel as a subassembly, with a root (attachment node) at the engine. In that case you need some dummy part. It can be a decoupler as it normally would be, but it can really be anything that has nodes on it. Attach it to the node on the bottom of the engine, then set it as root. Then pick the whole craft by the engine, leaving only the dummy part "solid" and drop it on the subassembly drop zone.

[Superfluous J]

In this particular case, the most reasonable approach is to have the whole vessel as a subassembly, with a root (attachment node) at the engine. In that case you need some dummy part. It can be a decoupler as it normally would be, but it can really be anything that has nodes on it. Attach it to the node on the bottom of the engine, then set it as root. Then pick the whole craft by the engine, leaving only the dummy part "solid" and drop it on the subassembly drop zone.

You don't need the dummy part. Just make the engine the root part and save the whole vessel.

[LordFerret]

Looks like this was an accidental double post but I wanted to respond to Lord Ferret to avoid confusion. You can drop a root part in a sub assembly as long as it has a stack attachment node free on the part your mouse is holding. In your example (assuming the Mk1 pod is the root) take the parachute or probe off and then drop it in sub assemblies, it will work, even if the pod remains root. Think of it this way, when you pull a subassembly OUT of storage, what do you attach it to? It has to have a node.

I stand corrected! Thanks.

[problemecium]

You can put the whole ship, including the root, in the subassembly box - but whatever the root of the subassembly is going to be has to have at least one attach node available.

So for instance you could have a probe with a docking port as the root become a subassembly like so:

port (root) - probe core - fuel - engine

but you could not make this into a subassembly without either re-rooting or removing the docking port:

port - probe core (root) - fuel - engine

Accordingly, when building something I intend to later use as a subassembly, I find it good practice to start with a docking port or similar attachment hardware.

[Major SNAFU]

Thanks to you all for the excellent replies.

My original post from done using my iPad. I don't know what it was posted twice. Very odd.

back to main topic: Armed with this knowledge I went on to redesign the probes and save them as sub-assemblies and then use then in dual, tri and quad adapter set ups (fore and aft) into various rockets. I think 4 will be the max for any one rocket.

I am trying to keep things on the small side and perform multiple launches instead.

This success lead me to the next evolution in the probes. I reconfigured the nose of the probes to be a docking port Jr and added RCS. the idea being to be able to launch and recover the probes.

At first I had a lot of trouble figuring out how to mount a decoupler on the docking port jr so that the decoupler did not remain on the docking port after separation. Actually, I succeeded by sheer luck and I don't know why it worked the way I wanted one the second attempt.

Is there way to use the docking ports themselves. I.e. I wanted to use the docking port Jr on one part of a bi-coupler and then attach the sub-assembly probe to this docking port using the docking port on he sub-assembly, but I could not get them to attach. Then I moved on to using a low-power decoupler on the docking port end and that worked, but that means I have to put the return docking ports somewhere else.

My final evolution so far are long range LRP-type probes with extendable solar panels. My hope is to use them for initial exploration, etc. Plus I wanted to see just how much I could pack into a very small probe.

My biggest issue now is that octagonal struts are the essential back bone of the probes, so it is alt-F12 and turn of all heating in the physics tab and the ignore temp for none of my probes last for more than a few moments on the launch pad....

Edited August 13, 2015 by Major SNAFU

[Superfluous J]

This success lead me to the next evolution in the probes. I reconfigured the nose of the probes to be a docking port Jr and added RCS. the idea being to be able to launch and recover the probes.

At first I had a lot of trouble figuring out how to mount a decoupler on the docking port jr so that the decoupler did not remain on the docking port after separation. Actually, I succeeded by sheer luck and I don't know why it worked the way I wanted one the second attempt.

All the decouplers have arrows on them. The arrows point to what will NOT be connected when you decouple. Usually this means 'up', but you can rotate them to make them be upside down if you want. However...

Is there way to use the docking ports themselves. I.e. I wanted to use the docking port Jr on one part of a bi-coupler and then attach the sub-assembly probe to this docking port using the docking port on he sub-assembly, but I could not get them to attach. Then I moved on to using a low-power decoupler on the docking port end and that worked, but that means I have to put the return docking ports somewhere else.

You can attach two docking ports to each other in the VAB, and they will be docked together so you can undock them. I can't imagine what you're doing incorrectly, so I'm going to take a guess: Did you flip one of them around? You need to do that, like the decoupler above.

My biggest issue now is that octagonal struts are the essential back bone of the probes, so it is alt-F12 and turn of all heating in the physics tab and the ignore temp for none of my probes last for more than a few moments on the launch pad....

Are the octostruts really that bad? I never use them. I either use the Modular Girder pieces or the Cubic Octagonal Strut, or occasionally the I-beams. I have never ever had one explode on me due to overheating.

Edited August 14, 2015 by 5thHorseman

[Alshain]

At first I had a lot of trouble figuring out how to mount a decoupler on the docking port jr so that the decoupler did not remain on the docking port after separation. Actually, I succeeded by sheer luck and I don't know why it worked the way I wanted one the second attempt.

Is there way to use the docking ports themselves. I.e. I wanted to use the docking port Jr on one part of a bi-coupler and then attach the sub-assembly probe to this docking port using the docking port on he sub-assembly, but I could not get them to attach. Then I moved on to using a low-power decoupler on the docking port end and that worked, but that means I have to put the return docking ports somewhere else.

You can decouple a docking port from anything. You do not need a decoupler or separator, or even another docking port at all. You can affix the docking port on the subassebly straight to the bi-coupler. Then in space, right click the port and choose the decouple option.

However, once decoupled, it can only re-couple with another docking port of equal size. Also, the engineering report will complain about it, ignore it.

As for attaching port to port in the VAB, it works, it's tricky. Try moving the camera so you are staring at the side of your target docking port, it works better that way.

[Major SNAFU]

Thanks for the additional replies. I did have the docking ports in the correct orientation (facing each other) - so I will try the view-based approach suggested by Alshain.

@5thhorseman re: octostruts - All I can report are the facts as they happen on my installations. I haven't had Kerbal that long (4 weeks), and there are other posts on the forum regarding sudden heating and explosions from far more experienced players than myself. What I have see is this: I have two careers going, one modded and one stock so I could compare them. I never had a 'random heating event' or 'sudden craft explosion' on a craft that had been in existence for a while until I progressed in both careers to the level where I had unlocked the octostruts and began to use them (to be fair, I also unlock other items at this same tech level at the same time). After that, in both careers, I began experiencing events where I would build a ship containing octostruts (because I had read how useful they are), would launch them and all would be well until you start using time acceleration - then I began loosing craft to explosions. (I posted in another thread with some details). In one instance, I have a probe 500 meters from the ground, chutes deployed, and it exploded within moments of going to 4X time acceleration. I reloaded many times and discovered that if I stayed at 3x or below, the probe never exploded. 4x, near instantaneous explosion. And in all of the cases I have had it, it was always an octostrut that had exploded. I happiness was taking a severe beating, so i searched toe forums and found many threads all on this topic. The more experienced people appeared to corroborate my findings, so I took the suggestion from one of the thread and activated ignore heat limit (or whatever it is called). However, I then found that if a craft overheated and I saved the game, then there was a good chance for an immediate explosion upon reload before I could turn off the heat stuff. So now, as soon as I load a save game, I turn on the ignore heat and also turn of the radiate, conduct, etc. heat in the physics tab. I would rather not - but I would rather play happy and without these than be frustrated with random explosions.

Is it the octostrut? I honestly don't know. Read the other posts about exploding ships and see what you think. There is definitely something amiss, and it only appears (for me) once I unlock the octostruts and similar level tech nology. What I have tested thoroughly is building ships with only the lower tech levels after you unlock the higher ones and see if the problem exists there now where it didn't before.

I can tell you that all of my mikro probes, which have multiple octostruts, will virtually all explode withing 30 seconds of my craft entering the launch pad. Nothing else explodes except the octostruts.

[LordFerret]

...

Also, the engineering report will complain about it, ignore it.

From personal experience; I've found that to be a quick way to make an engineer very angry. I recommend waiting until after-hours, buying them lots of beers (and then telling them), as it helps soften the blow to their ego.