Fairing / decoupler for clustered engines

[codepoet]

So I have started using the cubic octagonal struct trick for attaching multiple engines under a large tank to give me engine clusters. Great! I love it. However I now have a problem - how can I use this trick on an upper stage that is mounted vertically above a lower stage. I do not want to attach the lower stage to any one of the outer ring of engines, and if I attach a decoupler to the base of the tank of the upper stage it takes out the upper stage engines when it blows. It would also be nice to have fairing that enclose the whole engine cluster.

Does anyone know how to solve this problem, either in stock or with mods?

Ideally I want a 2m engine fairing compartment. I figured I could roll my own by hacking an exisiting 2m engine so it can do the stacking and fairing stuff, but have no thrust, and generally not be an engine. I had some success with this, but could not get rid of the 3d model (I tried replacing it with the model for a cubic octogonal struct) without loosing the model for the fairings .

I have started to looking into moding parts, and have downloaded Unity, but to be honnest it looks like a steep learning curve. Someone must have done this before? What is the solution?

Edited July 13, 2013 by codepoet
Question Answered

[Teirusu]

So I have started using the cubic octagonal struct trick for attaching multiple engines under a large tank to give me engine clusters. Great! I love it. However I now have a problem - how can I use this trick on an upper stage that is mounted vertically above a lower stage. I do not want to attach the lower stage to any one of the outer ring of engines, and if I attach a decoupler to the base of the tank of the upper stage it takes out the upper stage engines when it blows. It would also be nice to have fairing that enclose the whole engine cluster.

Does anyone know how to solve this problem, either in stock or with mods?

Ideally I want a 2m engine fairing compartment. I figured I could roll my own by hacking an exisiting 2m engine so it can do the stacking and fairing stuff, but have no thrust, and generally not be an engine. I had some success with this, but could not get rid of the 3d model (I tried replacing it with the model for a cubic octogonal struct) without loosing the model for the fairings .

I have started to looking into moding parts, and have downloaded Unity, but to be honnest it looks like a steep learning curve. Someone must have done this before? What is the solution?

Well, if you are looking into trying modded parts. You could try my cluster mounts

http://forum.kerbalspaceprogram.com/showthread.php/39049-Mobius-RocketWorks-Engine-Mounts-and-Parts

Unfortunately, they do not have fairings as I'm not sure how to add those to these parts. However, many of them are functional for upper stages. In most of the mounts I included two floating nodes under them that you can use to attach the lower stage, then use struts to properly connect them together. This usually ends up making a stronger connection, in anycase, engine fairings tend to cause wobbliness at times.

[regex]

One way to do this is to have a central engine or component that the decoupler can attach to between all the engines. Then use struts to strengthen the stage. For instance, if you have six engines mounted around the edge of a tank, put a seventh in the middle at the attachment point.

Be warned that the engines you've mounted around the central point may clip into the decoupler and cause problems; you'll want to make sure the outer components are adequately spaced.

[codepoet]

Well, if you are looking into trying modded parts. You could try my cluster mounts

Thanks for the link, I had infact already had a look at your work, and poked around inside to see how it was working.

In the end I have rolled my own solution, which have involved learnign a lot of stuff for the first time - blender, unity, part-tools. My head hurts but it will be easier next time!

So here is my solution - an engine enclosure fairing part. Here are a few pictures - the model and paint job is pretty noddy, and it looks like some guy on work experience has had a go with some blue paint in the bottom of the fairing attachment plate, but you can't see it too easily as it is mostly obscured by the engine cluster. Next time they make one in the PWB Kerbal rocket part factory they will hopefully pay more attention to these things...

So first I place cubic octagonal as the engine mountings to the base of the stack.

Next I add the fairing base plate

Then attach the engines in the cluster. Notice the connecting node in the centre a tthe bottom of the stack that the rest of the stack will be able to attach to.

Finally add a decoupler to the aforementioned node and the fairings are added around the engine enclose. There fairing provides enough structure that ther is no need for structs to brace the joint. There is a mass consideration for the fairing, however most of the mass is the actual fairing and not the base plate.

So here we are in orbit (or thereabouts) and we have just blown the decoupler. See how the fairing drifts off the end of the engines.

The quality for the model and paint job could be greatly improved, but if anyone is interested let me know and I will post the part.

[codepoet]

Can anyone tell me how to mark this thread as "answered?"

[Teirusu]

Hmmmm! Seems like I need to go through the same learning curve at some point so I can add a fairing to my mini adapter, and I should also make a 3 cluster version of it as well.