# [1.8.x] Mk2 Expansion v1.8.6.5 [update 11/9/2019]

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@ztoundas The second value in the triplet is the drag coefficient (not necessarily the coefficient of any particular axis). It is in effect the bluntness or steepness rating of the part. 1 = fully blunt; 0 = fully pointy; but note that the majority of pointy parts (in stock) are rated at about 0.37 which gives you a good sense of scale for this number. The M2X super-pointy nose or tail might have a noticeably lower Y+ (but not Y-) value. Congrats on that progress there.

Spoiler

The next lesson is how to approach animated parts such as inline docking nodes, cargo bays, elevons, and their 2 or 3 drag cube states. But that's for another day.

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@JadeOfMaar so I'm thinking that if the y-axis area from one part matches the y+axis area of another part, then the drag coefficient for those mating polarity axis is basically ignored because the difference between the two areas is 0, right?

So a stack of four identical parts traveling perfectly along the y axis should see that the middle two parts are experiencing virtually no drag?

But more important to the majority of my designs, how do bi and tri-couplers work? This particular mod has a tricoupler (with 1 auto-generated drag cube) that mates perfectly fine on the y + front side, but basically experiences full drag on the Y- back end as if three rapiers weren't connected to it. Yet the 3 rapiers say that Y+ end of their drag cube is fully connected and experiencing no drag, but of course the uncovered Y- back ends with the nozzles are experiencing drag (as one would expect.)

Edited by ztoundas
Corrected the polarity of a mentioned y axis

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11 hours ago, SuicidalInsanity said:

I'll add fixing the drag cube(s?) to the list. Out of curiosity, if you know, does the stock mk2 drone core ( which also doesn't have a custom drag cube defined in the .cfg and holes in the model) also display similar draggy behavior?

I noticed the same (but much worse) behavior of Mk1 DroneCore and Mk1SAS from Airplane plus. The part next to these parts creates enormous amounts of drag as if it was first in the stack without nosecone.

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(Edit: The following regards 1.8.0, but some problems remain after the patch, i.e hollow parts)

Now that I figured out last night what's causing all these drag issues, including was causing the really irritating drag issues with the stock cargo bays even when closed, I will work on submitting a proper bug report detailing what I found.

Turns out the explicitly specified drag cube for those bays (when closed), and a majority of the other stock parts that have abnormally high drag are because their drag cube has an extremely high drag coefficient on what we consider the bottom of the part when put into a horizontal stack like an airplane. This is when compared to other parts that act normally, like the MK2 LFO tank section of equal length. Last night I went through and smoothed out every part in my ship, and now the drag is nice and consistent concentrating on the areas that you would expect like a nose cone and the intakes and Tri couplers in the back.

Really there are two issues that affect the drag inappropriately on stock and modded parts. Some, like discovered earlier on in this troubleshooting path, get a miscalculated area for the front of the drag cube because the game gets confused when they have hollow internals. This is what was happening to the stock drone core and the modded RCS stability section. The other issue is that some simply have and abnormally high drag coefficient on the Z axis of the drag cube (around 0.92 instead of say 0.35-ish), which would be the belly of the plane. This was what was causing abnormal drag in the closed stock MK2 clamp-o-tron and cargo bays.

I'll take a look at the Spaceplanes Plus Pack and see what stands out there.

All that being said, does anyone know who does stock patches, or a way that this fix could be integrated into a stock fix mod? That's the kind of modding that I'm incredibly unfamiliar with, but it seems like it wouldn't be too hard to push a fix while the devs figure out a way to make the calculation of drag cubes more consistent.

EDIT: The latest patch update, 1.8.1, solved the inconsistent X axis drag (i.e the belly of the plane)! Values are far more consistent. The drone core is still broken on the Y -/+ axis, so I am doing a bug report for that.
Mods will still certainly be problematic for the hollow-part reason.

Edited by ztoundas
I updated my game and half the problems went away

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@ztoundas I can't help with bicouplers and tricouplers, sorry. I tend not to use those or not pay attention to potential aero issues in their general areas. I do tend to use the OPT J quadcoupler often, and when I only need to use 2 of the rear nodes (which is half of the time) I cap off the other two with nose cones larger than their nose size to try and meet that difference. I'm testing another part mod right now and I had to add an attach node to its most troublesome adapter parts, facing in the necessary direction, in order to make room for that "counterweight" nose cone.

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Yeah, I figured it just takes the added face areas for that axis of everything connected there and subtracts it from the area of that end of the coupler, but the ones in the mod are acting like it's got nothing there. To sidestep the issue so I can play, I've just dropped the coefficient of the coupling face until I figure out how to make it proper.

Oh and as for the crew portraits... I am embarrassed because I should have updated before reporting the problem... Because, @SuicidalInsanity, they are no longer missing after 1.8.1. Sorry for my lack of attention there.

Edited by ztoundas

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On 11/20/2019 at 12:03 AM, SuicidalInsanity said:

I'll add fixing the drag cube(s?) to the list. Out of curiosity, if you know, does the stock mk2 drone core ( which also doesn't have a custom drag cube defined in the .cfg and holes in the model) also display similar draggy behavior?

Yes, it does. A fuel tank behind the drone core creates up to 100 kN of drag while others create up to 10. I took a drag cube for Mk2 battery from parts database and copied it to the drone core cfg and it works. All fuel tanks create equal drag, the drag of drone core didn't change.

Dragcube for Mk2 battery also works for Mk2 SAS module but I'm not sure it's a good idea because it's twice shorter.

Edited by Manul

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M2X 1.8.6.6 is now up, which should fix the aero issues people have identified.
Grab from SpaceDock | GitHub
Changelog:
-Adds drag cubes for RCSAS, Aligned Dockingport, and Radial Mounts. These should generate much less drag now
-Fixes Sledgehammer AARE compile error
-Cockpit lights now uniform color
-Fixes R-71 cockpit IVA portraits, kerbals no longer occluded by instrument consoles
-Windowshine MM Patch now calls for TextureReplacer instead of the less up-to-date TextureReplacerReplaced

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would it be possible to get a half size lab or a cfg please ?

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On 11/25/2019 at 1:53 PM, budda said:

would it be possible to get a half size lab or a cfg please ?

Something like this? (requires MM)

Spoiler

+PART[mk2CrewCabin]
{
%name = ShortMk2Lab
%CrewCapacity = 1
%entryCost = 8400
%cost = 1750
%category = Science
%title = Short Mk2 Mobile Processing Lab MPL-XSM
manufacturer = #autoLOC_501624 //#autoLOC_501624 = C7 Aerospace Division
description = For when the MPL-SM Mobile Science Lab simply is too big. The MPL-XSM is half the size of the standard Mk2 Lab, and provides a minimum of off-world science processing capability. Features a Junior Chemistry starter set and an old magnetic tape recorder for keeping track of experiments.
%mass = 1.5

!MODULE[ModuleScienceExperiment] {}

MODULE
{
name = ModuleScienceContainer
reviewActionName = #autoLOC_502204 //#autoLOC_502204 = Review Data
storeActionName = #autoLOC_502202 //#autoLOC_502202 = Store Experiments
collectActionName = #autoLOC_238018 //#autoLOC_238018 = Take Data
evaOnlyStorage = True
storageRange = 2
allowRepeatedSubjects = True
}
MODULE
{
name = ModuleScienceLab
containerModuleIndex = 0
dataStorage = 250
crewsRequired = 1
canResetConnectedModules = True
canResetNearbyModules = True
interactionRange = 5
SurfaceBonus = 0.05
ContextBonus = 0.125
homeworldMultiplier = 0.1
RESOURCE_PROCESS
{
name = ElectricCharge
amount = 10
}
}
MODULE
{
name = ModuleScienceConverter
dataProcessingMultiplier = 0.1 // Multiplier to data processing rate and therefore science rate
scientistBonus = 0.12    //Bonus per scientist star - need at least one! So 0.25x - 2.5x
researchTime = 7        //Larger = slower.  Exponential!
scienceMultiplier = 4    //How much science does data turn into?
scienceCap = 250        //How much science can we store before having to transmit?
powerRequirement = 5    //EC/Sec to research
ConverterName = #autoLOC_502055 //#autoLOC_502055 = Research
StartActionName = #autoLOC_502056 //#autoLOC_502056 = Start Research
StopActionName = #autoLOC_502057 //#autoLOC_502057 = Stop Research
}
MODULE
{
name = ModuleKerbNetAccess
MinimumFoV = 17
MaximumFoV = 63
AnomalyDetection = 0
DISPLAY_MODES
{
Mode = Terrain,#autoLOC_438839 //#autoLOC_438839 = Terrain
Mode = Biome,#autoLOC_438890 //#autoLOC_438890 = Biome
}
REQUIRED_EFFECTS
{
Effect = ScienceSkill
}
}
MODULE
{
name = ModuleExperienceManagement
costPerKerbal = 0
}
}

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yes thank you just what i needed

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Nvm.

Question was about making scramjet work at higher altitudes than it does already. Which isn't possible due to how air pressure is calculated for the upper atmosphere.

Edited by Cruss

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