Building circular stuff in the VAB

[3mon]

Hi,

So i've been trying to build a big 'wheel' of sorts to dock in a big space station i'm working on. I first started with this idea:

But the VAB editor seems to hate it, and whenever i try to move anything or whatever, parts get sticked to my cursor, and all the buttons stop working. I have to alt+F4 or task manager out of KSP. When i reload, i get the same problem again and again. Sometimes i somehow manage to stick a subassembly rocket and hit the Launch button, but it bugs the hell out in the launch pad too. Sometimes it starts horizontally, missing all the arms altogether. And it always starts with missing parts, which are either fixed floating at some point close to the rocket, or laying on the ground nearby. The thing has 560 parts, and im pretty certain i've built and launched things with more parts with no problems (problems with bugs i mean lol).

Then i tried to simplify it a bit, and built this:

And i get exactly the same problems. I tried rebuilding it from scartch many times, I even tried enabling part clipping in the cheat menu, but it was all useless. I'm wondering, what the hell im i doing wrong here? Does the editor hate this type of building or does it simply hate me? Is it the parts clipping, or is it too big, or... i don't know! I'm pretty sure i've seen similar things in videos and so on, not to mention Whackjob's work here in the forums... Don't know, im pretty lost here guys... What can i do?

Thanks in advance!

Edited December 6, 2013 by 3mon

[numerobis]

Do your subassemblies have symmetry in them? If so, and you place the subassemblies with symmetry, sometimes all hell breaks loose. But sometimes it appears to work. It's annoying.

Otherwise, no idea.

[blizzy78]

Perhaps it's time to try the part welding plugin? I don't have any experience with that myself, though.

[3mon]

Do your subassemblies have symmetry in them? If so, and you place the subassemblies with symmetry, sometimes all hell breaks loose. But sometimes it appears to work. It's annoying.

Otherwise, no idea.

Yes, they have symmetry, all of them. However, all hell breaks loose here even before i load the subassembly

Anyway that could explain part of what's happening, thanks for the thought. I'm gonna go and try to attach a rocket without symmetry to it before it bugs.... If that's the case it's gonna be fun to lift that thing without using symmetry lol

Perhaps it's time to try the part welding plugin? I don't have any experience with that myself, though.

Hmmm very nice idea too! Hadn't occured to me either. Thanks!

Edited December 5, 2013 by 3mon

[Kimberly]

The structure of part relationships is strictly a tree. A part can have two child parts but not two parents--meaning a circle is not possible; the VAB will not make the attachment. (It is possible with docking ports, because once physics kicks in the parts will magnetically attach.) I suggest splitting up your design into two sections, connected by docking parts. Use the part welding tool to turn the section into one part, then slot the two parts together for a wheel--the docking ports will attach once you launch.

[3mon]

The structure of part relationships is strictly a tree. A part can have two child parts but not two parents--meaning a circle is not possible; the VAB will not make the attachment. (It is possible with docking ports, because once physics kicks in the parts will magnetically attach.) I suggest splitting up your design into two sections, connected by docking parts. Use the part welding tool to turn the section into one part, then slot the two parts together for a wheel--the docking ports will attach once you launch.

That actually makes a lot of sense, thanks! I'm definitely going to try the part welding plugin for this. But about dividing it in sections, you mean two halves of the whell, like ( and ), and docking them together?

[Kasuha]

You can either dock them together, or strut them together. Not long time ago I made similarly large wheel (see picture). I built 1/8 of the wheel manually, then copied it to the other side of the spoke, then placed the spoke with x4 symmetry and strutted ends of segments together. I had no problem at all with that. The strut can be seen at at the middle between spokes.

I think the main difference might be that I built the segment with symmetry off and then placed it with symmetry on when it was done.

Edit: okay, now I remember I did not use symmetry at all. The spokes were copied one by one and attached to the hub part in the middle separately.

Edited December 6, 2013 by Kasuha

[Steve-S]

It's my understanding that copying a copied part/assembly will cause the editor to bug out horribly and often result in the "whacked on the pad" syndrome of parts attached off axis etc. If I'm using sub assemblies I make that using all original parts, with no copies and then make all copies off of that one. I've had very good luck with that so far.

[Dogface]

WOW, that is an amazing piece of construction. Post a pic, when it gets to space. Why not make the docking ports flush, so when you get them to space, you can create a long cylinder?

Edited December 6, 2013 by Dogface

[3mon]

You can either dock them together, or strut them together. Not long time ago I made similarly large wheel (see picture). I built 1/8 of the wheel manually, then copied it to the other side of the spoke, then placed the spoke with x4 symmetry and strutted ends of segments together. I had no problem at all with that. The strut can be seen at at the middle between spokes.

I think the main difference might be that I built the segment with symmetry off and then placed it with symmetry on when it was done.

Edit: okay, now I remember I did not use symmetry at all. The spokes were copied one by one and attached to the hub part in the middle separately.

*snip*

That looks very nice indeed! Thanks for the input on symmetry, i think im gonna try a new desgin now and see how it works.

[Dogface]

... I built 1/8 of the wheel manually, then copied it to the other side of the spoke, ...

It's my understanding that copying a copied part/assembly will cause the editor to bug out horribly and often result in the "whacked on the pad" syndrome of parts attached off axis etc. If I'm using sub assemblies I make that using all original parts, with no copies and then make all copies off of that one. I've had very good luck with that so far.

What do you guys mean by "copy"? Is there a copy/paste feature in KSP I have been missing? Are you referring to manually duplicating or creating sub-assemblies?

[gl0ryh0und]

I've noticed that if I use Girders in a symmetry build it has a high chance of clitching, once it does the whole ship is garbage, even reloading is corrupted with one part of the symmetry containing the girder to be overlapped several times. Trying to remove the offending part and the editor gets confused about how to handle the part, it will delete all the parts fine except the overlapping parts, which no longer are connected to each other and won't delete when you pick them up and drop them to the left menu. I thought for a long time that this was because of a mod, but it happens in stock as well. Something to do with those girders, I've never notice the problem without them.

[Rhomphaia]

What do you guys mean by "copy"? Is there a copy/paste feature in KSP I have been missing? Are you referring to manually duplicating or creating sub-assemblies?

If you Alt+left click on a part, you will get a copy of that part with its rotational properties and all attached children.

Edited December 6, 2013 by Rhomphaia
added pic

[3mon]

Hmm just built this, with symmetry off (except for the subassembly im using to lift it) and everythign seems to be holding in place! Both in the VAB and in the launchpad! Although its much smaller, but oh well... If it works i'l try bigger.

For now, its time to go and try to dock this to the station

EDIT: So far so good

Edited December 6, 2013 by 3mon

[Kasuha]

So far so good

Congratulations!

[numerobis]

I've noticed that if I use Girders in a symmetry build it has a high chance of clitching, once it does the whole ship is garbage, even reloading is corrupted with one part of the symmetry containing the girder to be overlapped several times. Trying to remove the offending part and the editor gets confused about how to handle the part, it will delete all the parts fine except the overlapping parts, which no longer are connected to each other and won't delete when you pick them up and drop them to the left menu. I thought for a long time that this was because of a mod, but it happens in stock as well. Something to do with those girders, I've never notice the problem without them.

Nothing to do with girders IME; this is precisely what happens when you symmetrically place an assembly that itself has symmetry within. In code, each part stores a list of symmetric parts. When you have symmetries of symmetries, that list gets corrupted. Part A thinks it's symmetric to part B, which doesn't think it's symmetric to part A. Delete part B, and the game will not delete part A, because B isn't symmetric to A according to B's list. Later delete part A, and the game gets confused because where did part B go -- it's still in that list. I presume said confusion prevents it from getting around to handling clicks properly.

[3mon]

Success!!

Seemed to be the symmetry thing, at least in my case. Now im off to try something bigger for the other arm of the station heh

Thanks all!

[Taki117]

Success!!

PIC

Seemed to be the symmetry thing, at least in my case. Now im off to try something bigger for the other arm of the station heh

Thanks all!

My computer cries at the lag...

[Stone Blue]

In case you're interested, you could also give these a try:

(They are just single parts, no plugins)

http://kerbalspaceprogram.com/bigfrikinring/

http://kerbalspaceprogram.com/wayland-corp-space-station-o-ring-truss-pack/

[3mon]

In case you're interested, you could also give these a try:

(They are just single parts, no plugins)

http://kerbalspaceprogram.com/bigfrikinring/

http://kerbalspaceprogram.com/wayland-corp-space-station-o-ring-truss-pack/

Thanks! Those look very nice, although i dont usually use downloaded parts i think i may give those a go if i cant get along with building the rings myself

[Zephram Kerman]

I took an interest in ring / wheel / disk things too. Been having such a hard time, and learned a lot from this thread already! Keep it coming. I never thought of building rings without using symmetry, and sure enough, they often exploded on the launchpad.

Welded parts mod does indeed help, although its not yet perfect. If your welded part has a lot of nodes, sometimes it won't attach to anything. So one of my parts I had to manually edit out the extra nodes. (That wasn't so bad as it might sound.) For your inspiration, here are some ring things I made using Welded Parts mod:

Unfortunately, none of them are stable enough to fly. Perhaps they're just too big? I haven't figured out the problem yet. That disk actually is stable. My problem with that one is I want to make it into a wing, and launch it space plane style. Not likely to work.

[3mon]

Whoa! And i thought my original wheel was too big lol!

[3mon]

Ok i downloaded those parts from the Spaceport, and they look nice, but they are not integrated into career mode

So i tried to rebuild the original design with symmetry off.

And guess what, it seems to be working ok! No editor bugs so far. Its 115 tons, time to lift it! ;P

EDIT: Orbit achieved! Time for rendezvous after lunch

Edited December 7, 2013 by 3mon

[Taki117]

As far as adding things to the tech tree, all you have to do is add the following

TechRequired = (Whatever Tech node you want)
entryCost = (Has no real bearing on anything yet)

[Zephram Kerman]

Orbit achieved! Time for rendezvous after lunch

Congratulations! It looks really cool out there in the big dark.