Decoupler below multi-engine stage?

[*Aqua*]

Hi Kerbonauts!

What do you do to add a decoupler below a multi-engine stage?

I'm thinking hard about it but the only two solutions I came up with are
1) If there's a central engine, attach the decoupler there.
2) If there's no central engine, place a bar at the center and attach the decoupler there.

I also looked at the procedural parts mods. Unfortunately you can only change the diameter of a p-decoupler but not it's length.

So... what else can I do?

 

[regex]

33 minutes ago, *Aqua* said:

1) If there's a central engine, attach the decoupler there.
2) If there's no central engine, place a bar at the center and attach the decoupler there.

If you're talking vanilla KSP, yeah, one of those two options.  Add struts to taste.

33 minutes ago, *Aqua* said:

So... what else can I do?

I usually use an interstage from Procedural Fairings.

[Joco223]

You can put a smaller decouplwr then put a fairing beneath and connect the fairing to the egdes of engines and like that,you can have a shroud arround all engines

[softweir]

I have in the past modded the 1:3 adaptor to have a "spare" attachment node at the centre and slightly lower down , then attached a beam to the spare node and added the decoupler to that. The spare node has to be dropped a bit so the beam doesn't interfere with the engines!

These days I put a procedural fairings base above the 1:3 adaptor (with its floating node down!) and attached a second PF base to the floating node by its own floating node. Then I strut the whole thing solid, and add fairings.

[steuben]

you might be able to get away with attaching a decoupler to one engine and then nudging it to the centre, then build from there and strut it for strength

another way to attach a decouple to one engine then a 3 to 1 adaptor to go back to the main stack. add a couple of more decouplers for visual appeal and struts for structure

[SSgt Baloo]

I've always done it the hard way. decouplers on every engine node and an upended adapter beneath those. It can be problematic, but I've had some success.* I have experimented with putting a girder or an I-beam in the center location, and attach a decoupler to that, followed by a fairing of appropriate size. I've always put interstage fairings in their own stage (prior to any decouplers inside them) since I've had stages fail to decouple even though the decoupler was in the same stage as the fairing.

* Also a few failures. YMMV.

Edited February 18, 2016 by SSgt Baloo

[hellblazer]

Place decouplers under each engine and then flip another TVR-300L Stack Tri-Adapter underneath.

Edited February 18, 2016 by hellblazer

[Temstar]

26 minutes ago, hellblazer said:

Place decouplers under each engine and then flip another TVR-300L Stack Tri-Adapter underneath.

Doesn't work the way you think it does - only one of the three decoupler will be connected to the tricoupler.

I usually make my own cluster using BZ-52 Radial Attachment Point. It causes more drag but also offers greater flexibility than the stock multicouplers.

[pincushionman]

I thought I read in one of the devnotes that fairings, when used as an interstage, would add a virtual strut in the 1.1 code. Can't remember when I read that, though. Either way, not how it is now, and doesn't address how to actually attach it.

There is the technique of attaching decouplers, then docking ports, then one mating port under one engine, then the "mating" multicoupler, then stuffing the rest of the docking ports on that side. Only one is part of "the stack," but the others dock up when the physics engine starts. I've heard that works.

[GluttonyReaper]

If your not opposed to mods, this one might help in certain situations:

Custom Clusters

[AbacusWizard]

1 hour ago, Temstar said:

Doesn't work the way you think it does - only one of the three decoupler will be connected to the tricoupler.

Yes, but if you slap enough struts on it the other two decouplers are effectively connected to the tricoupler.

[Snark]

The SpaceY Heavy Lifters mod has some multi-engine adapters with shrouds that allow you to do what you're wanting to do.

[kurja]

6 hours ago, AbacusWizard said:

Yes, but if you slap enough struts on it the other two decouplers are effectively connected to the tricoupler.

Solution is to use docking ports instead of decouplers; that way you can have a connection at all 3 points.

[*Aqua*]

14 hours ago, regex said:

I usually use an interstage from Procedural Fairings.

This works perfect!

A big thank you to all of you for all suggestions!

[KerbonautInTraining]

Yeah, if you're OK with using mods to do it procedural fairings has an interstage that's fantastic for this. It's a bit hard to get used to though.

[Cornholio]

16 hours ago, hellblazer said:

Place decouplers under each engine and then flip another TVR-300L Stack Tri-Adapter underneath.

I've done it this way before and had success.  I can't really comment on if all decouplers were actually connected or not, but I had no reason to doubt it.  The only problem that I ran into was that when I staged (4 NERVs in a cluster), the shrouds shoot off sideways in separate pieces as opposed to the engine just sliding out.  This caused engines to go kablooey.  To get around that, I simple manually staged the decouplers, which meant that the shrouds for the NERVs never came off, but the engines still functioned correctly.

[KerbonautInTraining]

47 minutes ago, Cornholio said:

the shrouds shoot off sideways in separate pieces as opposed to the engine just sliding out.  This caused engines to go kablooey.

1.0.5 allows you to disable the shrouds, thankfully

[Francois424]

I would try and stick a Beam in the middle of your 3 engines, strut the outside (the 3 points of your 'triangle' to the decoupler.

Or you can add another inverted triangle below to contain the engines (just put stack decouplers for each engine).

But it will need strutting either way.

[Vanamonde]

This question about how to play the game has been moved to Gameplay Questions. 

[Lucky Spacer]

Posted to wrong forum. Can't figure out how to delete a post.

Edited May 11, 2016 by Lucky Spacer