How to use adapters and Nukes without the need for docking ports

[Monkeh]

So this issue nearly stopped me playing KSP as it was so frustrating to build a great rocket that fell apart at the adapter join. I've seen a few people posting about how to stop it happening so I thought I'd show you how I do it without the need for docking ports.

Add some fuel and then an adapter. Add your nuke engines next, decouplers under those and then an inverted adapter. For my example pictures I've used a quad adapter but the same principal applies for any of them. You can also just use thin tanks with engines and then the adapter, as long as the tanks originate from an adapter so the spacing between them is the same.

You'll need to add some mini girders around the top of your adapter. Then you add the same number under the adapter but in the same vertical plane. Connect them with struts and you're nearly done. The last thing to do is to rotate the engines using shift so that the seams of the fairings face outwards.

The number of girders and struts you use should be determined by the amount of radial tanks or engines you have underneath. You should use the same number and place them in the gaps between the tanks. So if you have 4 tanks under the nuke stage then use 4 girders/struts. If you have 8 then use 8 etc. The minimum for this to work is normally only 2, which is a lot less mass and fewer parts than the docking port method.

Here's some pictures of what I mean and a simple test rocket using this method.

Hopefully this will help a few people from getting too frustrated and actually get to the far away places in the Kerbol solar system.

Happy flying.

[Technical Ben]

It's not really ideal. It would be susceptible to wobble. So far I've kept to using asparagus staging, or docking nodes for reconnecting. Else I construct in orbit (for interplanetary +/ landing craft).

[Monkeh]

Asparagus staging for connecting adapters and engines? I am confused as to what you mean.

Have you tried it or are you theory crafting?

It doesn't wobble, I use it all the time and it works a treat.

[lammatt]

you cant use adapters to split into 4 and then back to 1

because you are making a loop

only one of the 4 adapter port at the lower end is considered by the game legitimately attached, that's why your rocket is unstable

if you want to split into 4 while still being able to build further down, use the radial mounts instead

[rodion]

Personally if I use the n-couplers on a rocket I never stack them linearly with anything else. Building outwards is the most bulletproof way, makes for a squat rocket but it's more stable and functional. If the current Unity engine allowed parts to snap onto multiple build nodes at once it would be a whole different story, but you have to play the game, so to speak.

[Monkeh]

you cant use adapters to split into 4 and then back to 1

because you are making a loop

only one of the 4 adapter port at the lower end is considered by the game legitimately attached, that's why your rocket is unstable

if you want to split into 4 while still being able to build further down, use the radial mounts instead

I'm sorry but did you even read my post? I'm showing that it is possible and easy to do with some simple strutting. My rockets are not unstable and I do what I outlined above and it works a treat.

I have flown many a rocket with that design and they never wobble, fall apart or break.

Personally if I use the n-couplers on a rocket I never stack them linearly with anything else. Building outwards is the most bulletproof way, makes for a squat rocket but it's more stable and functional. If the current Unity engine allowed parts to snap onto multiple build nodes at once it would be a whole different story, but you have to play the game, so to speak.

Building outwards is one option yeah, but I shall say it again, only this time in big letters:

THE METHOD OUTLINED ABOVE WORKS VERY WELL!

Edited September 24, 2013 by Monkeh

[Kasuha]

In case you need to put something heavy such as orange tank above these engines it may get wobbly and/or the struts may break. In such case it might be a good idea to go on with docking ports below separators instead of or in addition to struts.

Otherwise there's nothing wrong with that design.

[Technical Ben]

Theory, yes. In practice, I find using struts for support to be less stable than connected parts. I meant I use alternative designs, such as asparagus staging, instead of a branched tree down to single rocket type staging ( Like -<=>- as in your image).

Have you tried the above setup with docking ports? With docking ports you use 4 less parts (no struts) and it's rather stable. Under timewarp it wobbles, but that's more KSP than the design.

I'll upload a comparison video to Youtube. Struts are more stable under timewarp. Ports use less parts (and look nicer IMO ).

[capi3101]

I think what folks are saying is that the design would be unstable if you weren't bracing the payload. There's the key - the extra struts are what makes the design stable enough to fly. Without them, the damn thing would buck like a bronco...I learned that the hard way - the Storax Anacostia mission had a 1-to-4-to-1 stacking between the booster and the transfer stage, it did not use strutting or docking ports, and I'd've liked to have never gotten the damn thing into orbit (ultimately had to do a slow burn, which is not what you want to do when you're trying for orbital insertion).

Three out of four of your fairings explode when you decouple without using docking ports, to which I say "Big Deal." Nothing important is damaged and you can literally start your missions with a bang...

(Talking about the fairings over the engine bells here, not those annoying LV-N sheaths).

Incidentally, I have tried using docking port/decoupler combos. They're dandy provided you haven't got a lot of mass on either side of the port, otherwise they're useless (in my experience, anyway; others may have had different results).

Edited September 24, 2013 by capi3101

[Monkeh]

Well yeah capi3101, that is the whole point of this thread. without the struts it does wobble all over the place and eventually fall off in a rather comedic fashion. With the struts it's a gloriously stable concoction. The explosions always make we panic but when I turn on the engines and everything works it's all worth it, and yeah, I like bangs that don't kill, maim or injure

I haven't tried it with docking ports Technical Ben, because I found this way of doing things before the thread on here somewhere mentioned the ports and I just carried on doing what worked for me.

I also use asparagus staging for getting up to orbit but these days I tend to swallow my pride and time with low TWr nukes and a whole load of fuel. I can handle a 16 minute burn, KSP can take an alt-tab pretty well after all

[Technical Ben]

Here is the video:

The conclusion? Docking ports look nicer and tend to be smoother for flight. Struts are stronger and take more "abuse".

Use both for the best result in strength.

[lammatt]

lol at people ask for advice and dont take it.

[Starwaster]

lol at people ask for advice and dont take it.

Who did that?

[Monkeh]

lol at people ask for advice and dont take it.

lol at people seeing question marks in a thread title where there is none!

Nice one Ben. I wouldn't use timewarp on launch anyway, but I get it shows of any instabilities. So yeah, I'm glad you proved the struts work as it seems some people didn't believe it would without even testing it...

As stated in the title, it's just another way of doing the same thing and maybe the lower mass of the strut version may be useful to some.

[VaporTrail]

I did something very similar.

Basically instead of putting another adapter below the nukes, I simply strapped a LV45 to a decoupler and put them directly below the nuke. I just jettison the LV45s just before I finalize my circularization for low orbit, letting them reenter, and finish orbital insertion on the nukes.

[Technical Ben]

From my experience, struts working that way add little extra strength. They stop wobble, but you still tend to have a top heavy rocket crash down on the stages below.

Launching my double orange tank to orbit delivery system uses both docking ports and struts, and even then it's delicate.

Also, very few statements can be given that cannot be questioned.