Inter-stage Fairings

[CodeFantastic]

  Have you ever build a rocket with an upperstage that you wanted to have 2 engines? (say 2 Terriors under a 2.5m fuel tank) but you weren't able to do so because of the way decoplers work? In procedural fairings, you could solve this problem by using an interstage fairing instead of decoplers. I hope they add something like this with the stock fairings so we can have a bit more freedom with upperstage engines.

[Red Iron Crown]

Already a thing, the stock fairings can close on a cylindrical part instead of coming to a point, forming an interstage fairing (though it can be finicky at times). You can also toggle off the autofairings on the engines when they're not needed in such applications.

[KerikBalm]

I find interstage fairings nearly impossible to make in the SPH for some reason... many designs I simply gave up trying to make them, and just clipped the fairing through the payload (remove payload, make fairing, put payload back) - although I'm not sure how the aerodynamics work in that case, and it sometimes results in explosions upon decouple... they really need to lessen the tolerances needed to get interstage fairings... "find the exact camera angle and pixel" is not a fun game

[tater]

2 hours ago, Red Iron Crown said:

Already a thing, the stock fairings can close on a cylindrical part instead of coming to a point, forming an interstage fairing (though it can be finicky at times). You can also toggle off the autofairings on the engines when they're not needed in such applications.

I know this is theoretically possible, but it's so finicky that I stopped trying, frankly. It's not at all tricking in PF, so the stock fairings need to be made so they simply work, 100% of the time trying for this in stock, or they need to add an interstage part of that is what it takes.

[The Great Potato]

2 hours ago, Red Iron Crown said:

Already a thing, the stock fairings can close on a cylindrical part instead of coming to a point, forming an interstage fairing (though it can be finicky at times). You can also toggle off the autofairings on the engines when they're not needed in such applications.

Kind of a thing.

If you try to wrap an interstage around anything with a relatively small diameter, you end up with a really bendy rocket. Modules packed up Apollo LEM style and engine clusters come to mind.

You can reinforce the interstage, but it will always be a little noodle-y even with an excessive number of struts.

Since I have an obsession with engine clusters, I'd use the living hell out of a stock interstage option. I like the stock fairings better than PFairings - they're way cleaner and less fiddly. It would be nice not to have to install PFairings just to have interstage nodes.

[Alshain]

5 hours ago, Red Iron Crown said:

Already a thing, the stock fairings can close on a cylindrical part instead of coming to a point, forming an interstage fairing (though it can be finicky at times). You can also toggle off the autofairings on the engines when they're not needed in such applications.

In addition to what RIC said, with a mod you can toggle off staging of said fairing.  Not applicable in your case, but still useful in some designs.  The only thing you can't do is a partial deploy able fairing  and TD&E like Apollo and the Lunar Module.

@PART[*]:HAS[@MODULE[ModuleProceduralFairing]]:FINAL
{
	@MODULE[ModuleProceduralFairing]
	{
		stagingEnableText = Fairing: Enable Staging
		stagingDisableText = Fairing: Disable Staging
		stagingToggleEnabledEditor = true
	}
}

 

2 hours ago, The Great Potato said:

Kind of a thing.

If you try to wrap an interstage around anything with a relatively small diameter, you end up with a really bendy rocket. Modules packed up Apollo LEM style and engine clusters come to mind.

You can reinforce the interstage, but it will always be a little noodle-y even with an excessive number of struts.

Since I have an obsession with engine clusters, I'd use the living hell out of a stock interstage option. I like the stock fairings better than PFairings - they're way cleaner and less fiddly. It would be nice not to have to install PFairings just to have interstage nodes.

You can strut it creatively and make it work.  It is true that the fairing base can not recieve a strut connection but it can have a Rockmax Brand Adapter 02 on top of it that can receive struts.  A little extra mass, yes, but it works.  So then your struts all appear inside the interstage fairing and you don't see it until you stage the fairing, and then you are ready to decouple anyway.

Edited April 13, 2016 by Alshain

[CodeFantastic]

8 hours ago, Red Iron Crown said:

Already a thing, the stock fairings can close on a cylindrical part instead of coming to a point, forming an interstage fairing (though it can be finicky at times). You can also toggle off the autofairings on the engines when they're not needed in such applications.

 Yes, I know you can do this, but only if there's one engine in the middle. I'm saying for two engines that are offset from the center. The only way to do it is put a decopler between them but the stock decoplers are far too big.

[Alshain]

33 minutes ago, CodeFantastic said:

 Yes, I know you can do this, but only if there's one engine in the middle. I'm saying for two engines that are offset from the center. The only way to do it is put a decopler between them but the stock decoplers are far too big.

Unfortunately, that is due to game mechanics.  You can't have more than one attachment.  However there are creative ways to work around that using the tools you have been given.

 

Edited April 13, 2016 by Alshain

[CodeFantastic]

30 minutes ago, Alshain said:

Unfortunately, that is due to game mechanics.  You can't have more than one attachment.  However there are creative ways to work around that using the tools you have been given.

 

 This works, but I like my engines not sticking out like that, and this doesn't work well with just a 1.25 to a 1.25 :/

[Alshain]

2 minutes ago, CodeFantastic said:

 This works, but I like my engines not sticking out like that, and this doesn't work well with just a 1.25 to a 1.25 :/

I was doing it in a hurry (I'm running on an Intel CPU built-in graphics card atm, it was incredibly slow).  You can adjust the engines in a little.  Play with it.  Also it would work with 1.25 to 1.25 but you would need smaller engines, that is typical of any real rocket like that though, but you have 3 engines, what did you expect? Either that our you would have to accept some protrusion of the fairing.

Edited April 13, 2016 by Alshain

[The Great Potato]

8 hours ago, Alshain said:

I was doing it in a hurry (I'm running on an Intel CPU built-in graphics card atm, it was incredibly slow).  You can adjust the engines in a little.  Play with it.  Also it would work with 1.25 to 1.25 but you would need smaller engines, that is typical of any real rocket like that though, but you have 3 engines, what did you expect? Either that our you would have to accept some protrusion of the fairing.

Nah, it's fine. There's no real way to make the workaround look pretty. Usually, I use pancakes for the extra fuel and easier fuel line attachment when clipped in.

I use this setup a lot, but I have a bunch of problems with it (other than the obvious aesthetic issues):

First, Having the decoupler there can cause issues, especially if you move the engines a little further inward. I've had a bunch of launches where the girder/decoupler collides with an engine and goes kablooey.

Second, this uses a size 0 to hold up a size 2. You can strut it up, but struts won't give back the rigidity of an actual 2->2 connection. There will always be some degree of flex at that joint.

Third, this is a hack. Getting this to work requires a lot of clipping and every part involved is used in a way that's not intended. Most importantly, it completely ignores a series of parts that are actually intended for this purpose - bi/tri/quad adapters.

 

The adapters should be slimmed down so they actually fit under 2.5m tanks. Adapting and un-adapting a stack should also join all the hanging nodes together. In addition, adapters need to be moved waaay down the tech tree (meta-materials? really?). That would at least solve engine clusters.

As for payload interstages...I think the fairings could use a toggleable interstage node, but I don't see that happening in stock.

[Alshain]

6 hours ago, The Great Potato said:

Nah, it's fine. There's no real way to make the workaround look pretty. Usually, I use pancakes for the extra fuel and easier fuel line attachment when clipped in.

I use this setup a lot, but I have a bunch of problems with it (other than the obvious aesthetic issues):

First, Having the decoupler there can cause issues, especially if you move the engines a little further inward. I've had a bunch of launches where the girder/decoupler collides with an engine and goes kablooey.

Second, this uses a size 0 to hold up a size 2. You can strut it up, but struts won't give back the rigidity of an actual 2->2 connection. There will always be some degree of flex at that joint.

Third, this is a hack. Getting this to work requires a lot of clipping and every part involved is used in a way that's not intended. Most importantly, it completely ignores a series of parts that are actually intended for this purpose - bi/tri/quad adapters.

 

The adapters should be slimmed down so they actually fit under 2.5m tanks. Adapting and un-adapting a stack should also join all the hanging nodes together. In addition, adapters need to be moved waaay down the tech tree (meta-materials? really?). That would at least solve engine clusters.

As for payload interstages...I think the fairings could use a toggleable interstage node, but I don't see that happening in stock.

To address the first issue, the decoupler is tricky but you can adjust it's ejection force and be more patient and move away slowly.  Even in the atmosphere on a lower stage you have plenty of time to allow that to happen

Secondly, struts are massively overpowered so it will be plenty rigid.  You should have no issues at all as long as you strut between the 2.5m tank and the 2.5m adapter to ensure all the smaller joints are removed from the equation*.  If you strut between any thing else, like the engines and the girder you are basically not doing much.

For your third argument, it isn't a hack, the game was designed to do this sort of thing.  The game engine has it's limits and as the player you find creative ways of doing things, otherwise everyones rockets would be identical.  If that were the case Squad could save us a lot of trouble and remove the parts list and just have a bunch of pre-built single piece rockets for us to use like Orbiter.  But that isn't what the game is, it instead is a game of Lego-like rocket pieces for you to figure out new ideas and designs.  Or perhaps you are the type of person that got a pack of Legos and only ever built the design on the instruction sheet?  In any case, it's not a hack, it's KSP. Squad even gave you the 'gizmo' tools to do just such tricks.

As for the couples, the are fine parts but not perfect for all scenarios.  They are primarily meant for first stages, you can make them work for other purposes but in the end the game treats craft in a tree view.  You can open the craft file and see it.  Because of this format, non-radial parts can only attach to one piece. i.e. Command Pod -> Fuel Tank -> Engine -> Decoupler.  What can never happen is: Command Pod -> Fuel Tank ->  3x Engines -> Decoupler.  It just isn't possible with the construct of the game.  You can use 2 of the bi/tri couplers, one upside down at the bottom, but it is still going to only attach to one of the 3 engines and you will need to strut the other two.  This fact will never change, suggesting it is futile, as it would require basically starting over on much of the game itself.  In any case, re-tooling the interstage fairing will not solve this problem.  Also, the bi/tri couplers stick out just like my engines above did so you are still going to have to protrude the fairing, changing the interstage fairing won't fix that either.  I'm sorry to say it but there simply isn't a best solution to this problem, nor is there really one that could be developed, you are going to have to make do, fortunately that is what KSP is all about.

 

*Figure of speech, they aren't technically removed from any equations

I don't think the adapters can be slimmed down either.  The 1.25m nodes already touch each other, they are about as slim as it gets.

[klesh]

In the stock game, you have to make due with what is there.  Many of my designs get changed based on how it will function in KSP.   Check out Bob Fitch on youtube for some sweet examples of how to achieve what you're after.   Welding parts and adding nodes to his custom parts so his rockets are precisely what he wants them to be.   Sure, its a pain in the butt, but its either that or making due with the KSP tools. 

[Alshain]

36 minutes ago, klesh said:

In the stock game, you have to make due with what is there.  Many of my designs get changed based on how it will function in KSP.   Check out Bob Fitch on youtube for some sweet examples of how to achieve what you're after.   Welding parts and adding nodes to his custom parts so his rockets are precisely what he wants them to be.   Sure, its a pain in the butt, but its either that or making due with the KSP tools. 

Well, this is the suggestion forum, making suggestions for new parts is not wrong.  The problem is what he wants isn't possible with the design structure of the game's files (to the best of my knowledge).

To better illustrate the issue, this is an example of how the above craft is stored in the text based craft file.  Notice how there is no way to put that second Tri-Adapter under all 3 engines in a standard tree view.  In fact the other two decouplers could be completely omitted as they really do nothing at all.

Edited April 14, 2016 by Alshain

[KerbonautInTraining]

23 hours ago, Alshain said:

It is true that the fairing base can not recieve a strut connection 

That's been fixed since the first 1.1 pre-release, thankfully.

[The Great Potato]

3 hours ago, Alshain said:

To address the first issue, the decoupler is tricky but you can adjust it's ejection force and be more patient and move away slowly.  Even in the atmosphere on a lower stage you have plenty of time to allow that to happen

Secondly, struts are massively overpowered so it will be plenty rigid.  You should have no issues at all as long as you strut between the 2.5m tank and the 2.5m adapter to ensure all the smaller joints are removed from the equation*.  If you strut between any thing else, like the engines and the girder you are basically not doing much.

For your third argument, it isn't a hack, the game was designed to do this sort of thing.  The game engine has it's limits and as the player you find creative ways of doing things, otherwise everyones rockets would be identical.  If that were the case Squad could save us a lot of trouble and remove the parts list and just have a bunch of pre-built single piece rockets for us to use like Orbiter.  But that isn't what the game is, it instead is a game of Lego-like rocket pieces for you to figure out new ideas and designs.  Or perhaps you are the type of person that got a pack of Legos and only ever built the design on the instruction sheet?  In any case, it's not a hack, it's KSP. Squad even gave you the 'gizmo' tools to do just such tricks.

I'm very familiar with the fixes, I do them all the time. And no, the struts are often not quite enough. Even with 10-20 struts between the adapter and the tank, there's a little more flex than if I were to use a skipper or poodle in place of a reliant cluster. A little extra bendiness halfway down the rocket is not optimal, to say the least. 'Spam struts' is always an option, but I don't like it.

It's still totally is a hack by my definition, and not because of clipping. Squad specifically disabled radial attachment on engines; those cubic struts are used to circumvent that. But that's splitting hairs - regardless of what I call a hack, I'd prefer a more elegant solution to interstages and clustering.

3 hours ago, Alshain said:

As for the couples, the are fine parts but not perfect for all scenarios.  They are primarily meant for first stages, you can make them work for other purposes but in the end the game treats craft in a tree view.  You can open the craft file and see it.  Because of this format, non-radial parts can only attach to one piece. i.e. Command Pod -> Fuel Tank -> Engine -> Decoupler.  What can never happen is: Command Pod -> Fuel Tank ->  3x Engines -> Decoupler.  It just isn't possible with the construct of the game.  You can use 2 of the bi/tri couplers, one upside down at the bottom, but it is still going to only attach to one of the 3 engines and you will need to strut the other two.  This fact will never change, suggesting it is futile, as it would require basically starting over on much of the game itself.  In any case, re-tooling the interstage fairing will not solve this problem.  Also, the bi/tri couplers stick out just like my engines above did so you are still going to have to protrude the fairing, changing the interstage fairing won't fix that either.  I'm sorry to say it but there simply isn't a best solution to this problem, nor is there really one that could be developed, you are going to have to make do, fortunately that is what KSP is all about.

I don't think the adapters can be slimmed down either.  The 1.25m nodes already touch each other, they are about as slim as it gets.

Eh, you're right. It's a very unlikely option, but I wanted to suggest something other than interstage attachment nodes. Squad seems to prefer features that don't involve hanging attachment nodes or fiddly sliders, and I tend to agree.

Allowing multiple parents isn't as complicated as you make it sound, though. Squad could stick with the tree model and keep special cases for stack splitters. Or they could change to a graph model, which - assuming the root still can't have a parent - is nearly the same as a tree for downward traversal, subtree removal, and re-rooting. Upward traversal is the real killer, but I can't think of a place where it's used in-game at the moment. Regardless, this requres a change that's deeper than the modding API. Suggesting a mod with this feature would be futile.

There are rumors of a v1.2 rocket rework, so recommending such a major change to bi/tri/quad adapters isn't completely out of the question.

Edited April 14, 2016 by The Great Potato

[Alshain]

41 minutes ago, KerbonautInTraining said:

That's been fixed since the first 1.1 pre-release, thankfully.

Nice, I was unaware of that.  Can't wait!

@The Great Potato  I don't know what to tell you then.  Perhaps a mod or something gone awry?  On a good installation of a stock game there should be no flexibility with just a few struts, assuming they are placed correctly.  @Snark wrote a wonderful writeup in this thread on that topic so I won't bother re-inventing the wheel.

Switching the tree method to something else isn't likely to happen, and multiple parents i a very complicated process.  It's not just tying them together within KSP, it is telling the Unity physics engine to make them behave properly.  As I understand it, the Struts themselves are a pretty nasty hack they had to do out of necessity just to make Unity behave the way they wanted.  They don't have a lot of control over what Unity does.

The rocket rework that is rumored is mostly the part models getting a visual update to be higher quality as the plane parts are now (lets face it, you make a rocket that combines the plane and rocket parts and it looks terrible).  I'm sure changes can be made for the model, but as I said, the models for those couplers are about as compact as they can be.  It's not that they can't redo the part, it's that they are as tight as they get.  How would you design them?  The 1.25m engines mounted to any of those parts are practically touching.  They could switch to butt-less engines (which I support) but if that isn't a route they want to go then I think the shape you have is as good as it gets.

[Frank_G]

I use the stock fairings for interstage fairings almost all the time. Even if an engine has the desired base width. I also use them as cover for capsules and as size adapters, like in this Ares I replica.

There is lots of stuff to be put under the hood, like separatrons, RCS tanks and thrusters and other things - the stock fairings are ideal for that. And i find them quite easy and comfortable to use. The only thing that is a bit annoying, is that they dont accept radial attachments. But it seems, like this issue is already fixed in 1.1. No need for different parts in my opinion.

[The Great Potato]

@Alshain No mods. Size 3 with a cluster of 5 engines; with 12 struts placed in a truss pattern around the edges, the rocket is slightly more noodle-y than if I used a rhino. Not by much, but enough to give it a noticeable wobble.

I didn't really consider unity's physics...KSP itself usually only goes downward, but I imagine physics would constantly be going either direction...okay, you convinced me. I can still hope, though 

I was gonna bring up the auto-tankbutt on the Vector. I've had my fingers crossed for mounting-less engines since I saw that. Butts won't do anything for the adapters, though...they still need to mount tanks without clipping. How about a stock thrust plate?

@Frank_G The stock fairings work great as interstages in a bunch of situations. The main problems are when you want to put a fairing around something with no center node, or when you're packing a payload LEM-style. You have to spend an awful lot of parts so it jettisons properly and doesn't flop around in flight.

[Red Iron Crown]

On 4/12/2016 at 4:52 PM, Alshain said:

 It is true that the fairing base can not recieve a strut connection...

 

1 hour ago, KerbonautInTraining said:

That's been fixed since the first 1.1 pre-release, thankfully.

Fairing bases could always receive fairing connections, it's been that way since their introduction. What has changed in 1.1 is that now the strut can initiate from the fairing base, which has several advantages, the biggest of which is the mass of the strut staying with the lower stage instead of the payload.

[Alshain]

2 minutes ago, The Great Potato said:

@Alshain No mods. Size 3 with a cluster of 5 engines; with 12 struts placed in a truss pattern around the edges, the rocket is slightly more noodle-y than if I used a rhino. Not by much, but enough to give it a noticeable wobble.

I'm confused.  There is no 5 engine adapter?  I thought you said you were using the adapters. I feel like this has to be a design issue, maybe add a screenshot?

[AlamoVampire]

Hi guys. This is why I feel the stock "fairings" are absolute garbage and think Squad screwed up not making the mod Procedural fairings stock. Proc fairing needs no special mm coding, its absolutely user friendly and intuitive where the stock attempt at fairings is none of this. Plus Proc Fairings HAS an interstage fairing node. Just saying.