The MH structural tubes

[Firemetal]

Can someone confirm that these things create a lot of drag?

[HvP]

The procedural structural tubes don't seem to shield anything from drag, so it's like having a gap in the middle of your stack as far as aerodynamics are concerned. Also, they apparently don't protect anything inside of them from heat either. I tried making an escape pod out of one of them and not only do my Kerbals inside show aero drag lines, they also explode during reentry as if they are directly exposed to the heating.

[Firemetal]

Ahh that's a bummer. Think of the giant cargo planes you could builld if they had good aerodynamics. 

Fire

[Tyko]

31 minutes ago, HvP said:

The procedural structural tubes don't seem to shield anything from drag, so it's like having a gap in the middle of your stack as far as aerodynamics are concerned. Also, they apparently don't protect anything inside of them from heat either. I tried making an escape pod out of one of them and not only do my Kerbals inside show aero drag lines, they also explode during reentry as if they are directly exposed to the heating.

Has this been reported as a bug? every time I turn around I discover more ways they cut corners/slipped up on MH development. It seems like they're doing better now, but MH was definitely a low point in KSP quality.

[OHara]

Bugs  https://bugs.kerbalspaceprogram.com/issues/19376 and https://bugs.kerbalspaceprogram.com/issues/18126

[bewing]

1 hour ago, HvP said:

The procedural structural tubes don't seem to shield anything from drag, so it's like having a gap in the middle of your stack as far as aerodynamics are concerned. Also, they apparently don't protect anything inside of them from heat either. I tried making an escape pod out of one of them and not only do my Kerbals inside show aero drag lines, they also explode during reentry as if they are directly exposed to the heating.

As far as I'm concerned, clipping has never shielded anything from drag or heat, so expecting either behavior from a part is foolish wishful thinking. It surprises me that it's such a common complaint about these tubes. That's what cargo bays, service bays, service modules, and fairings are for. Which isn't to say that they may not add that feature anyway.

The aero part would certainly be a bug though. The tubes are supposed to behave just like a procedural structural fuselage. So I'll see if I can confirm the bugs that OHara listed.

Edited January 23, 2019 by bewing

[Firemetal]

@bewing Using the structural tubes as cargo bays isn't clipping though. They have nodes for placement inside. I think they could be great cargo holders if they were aerodynamically sound. There really isn't enough diversity with cargo bays in the stock game.  But this thread is turning into more of a suggestion thread than a q&a thread.

Thanks for answering my question though.

Fire

[HvP]

1 hour ago, bewing said:

As far as I'm concerned, clipping has never shielded anything from drag or heat, so expecting either behavior from a part is foolish wishful thinking. It surprises me that it's such a common complaint about these tubes. That's what cargo bays, service bays, service modules, and fairings are for. Which isn't to say that they may not add that feature anyway.

The aero part would certainly be a bug though. The tubes are supposed to behave just like a procedural structural fuselage. So I'll see if I can confirm the bugs that OHara listed.

It's just the simple fact that it defies expectation. A hollow tube of that sort in real life would shield items inside from drag and to some extent from heat. When these parts were released I was hopeful that they would serve such a purpose. Now I know that they do not, which I think unfortunately limits their usefulness. I seldom have the need to add long empty sections of dead weight to my rocket unless I specifically want to pack it full of smaller parts like batteries, monoprop tanks, science experiments, fuel cells, RTGs, command chairs, etc. and the stock cargo bays in the 1.25 and 2.5 cross-section are either far too ugly,  far too short or not available in the cross-section I need. Or, in the case of the Gemini/Apollo style 1.85 & 2.5 service bays, far too tall with a poorly optimized interior for what I need.

So I just have to make do with making heavy interstage fairings with that ugly ugly mismatched base, or tweakscale other parts as best I can.

Edited January 23, 2019 by HvP

[Aegolius13]

I have a vague recollection of trying to use one of these tubes just to add length (nothing stowed inside), and getting a ton of drag on the part attached to the rear node.  So that's a step worse than,  say,  the structural fuselage.

[Gargamel]

Moved to Making History Discussions

[DMagic]

This has been reported a few times starting when MH was first released. One of the reports even has the corrected drag cubes that would at least make the part not cause too much drag.

Given how long they've been left in their broken state I wouldn't hold out much hope for them being fixed any time soon. But maybe if everyone up votes those reports it will get looked at.

[Tonka Crash]

From a post @OHara made:

Spoiler

// Make Structural Tubes shield the parts inside them from drag
@PART[Tube*] {
    MODULE,0 {
        name = ModuleColorChanger
        toggleInEditor = false
        toggleInFlight = false
    }
    %MODULE[ModuleCargoBay] {
        DeployModuleIndex = 0
        lookupCenter = 0,-0.5,0 // Tubes extend from 0 to some negative Y
        lookupRadius = #$/MODEL:HAS[#scale[*]]/scale[0]$
        nodeOuterForeID = top2
        nodeOuterAftID = bottom2
        nodeInnerForeID = top1
        nodeInnerAftID = bottom1
    }}

// Make the engine-plate shrouds shield the parts inside them from drag
@PART[EnginePlate*] {
    %MODULE[ModuleCargoBay] {
        DeployModuleIndex = 3  // Index of the jettison module for all plates as of Aug2018
        lookupCenter = 0,-0.5,0 // Shrouds extend from 0 to some negative Y
        lookupRadius = #$/MODEL:HAS[#scale[*]]/scale[0]$
        nodeOuterForeID = top
        nodeOuterAftID = bottom
        nodeInnerForeID = top
        nodeInnerAftID = bottom
    }}

// repair bug 19376, missing configuration that is needed for parts with hollow ends
@PART[Tube1] {
	%DRAG_CUBE {
		cube = 0, 0.78,0.78,0.71, 0.78,0.78,0.71, 1.21,0.96,0.10, 1.21,0.96,0.10, 0.78,0.78,0.71, 0.78,0.78,0.71, 0,-0.3125,0, 1.25,0.625,1.25
		cube = 1, 1.56,0.78,0.71, 1.56,0.78,0.71, 1.21,0.96,0.10, 1.21,0.96,0.10, 1.56,0.78,0.71, 1.56,0.78,0.71, 0,-0.625,0,  1.25,1.25,1.25
		cube = 2, 2.36,0.77,0.68, 2.36,0.77,0.68, 1.21,0.96,0.10, 1.21,0.96,0.10, 2.36,0.78,0.68, 2.36,0.78,0.68, 0,-0.9375,0, 1.25,1.875,1.25
		cube = 3, 3.12,0.78,0.69, 3.12,0.78,0.69, 1.21,0.96,0.10, 1.21,0.96,0.10, 3.12,0.78,0.69, 3.12,0.78,0.69, 0,-1.25,0,   1.25,2.5,1.25
		cube = 4, 4.72,0.77,0.60, 4.72,0.77,0.60, 1.21,0.96,0.10, 1.21,0.96,0.10, 4.72,0.77,0.60, 4.72,0.77,0.60, 0,-1.875,0,  1.25,3.75,1.25
	}}
@PART[Tube1p5] {
	%DRAG_CUBE {
		cube = 0, 1.18,0.77,1.01, 1.18,0.77,1.01, 2.72,0.96,0.10, 2.72,0.96,0.10, 1.18,0.77,1.01, 1.18,0.77,1.01, 0,-0.3125,0, 1.875,0.625,1.875
		cube = 1, 2.36,0.77,1.01, 2.36,0.77,1.01, 2.72,0.96,0.10, 2.72,0.96,0.10, 2.36,0.77,1.01, 2.36,0.77,1.01, 0,-0.625,0,  1.875,1.25,1.875
		cube = 2, 3.52,0.78,1.01, 3.52,0.78,1.01, 2.72,0.96,0.10, 2.72,0.96,0.10, 3.51,0.77,1.00, 3.51,0.77,1.00, 0,-0.9375,0, 1.875,1.875,1.875
		cube = 3, 4.69,0.78,1.00, 4.69,0.78,1.00, 2.72,0.96,0.10, 2.72,0.96,0.10, 4.69,0.78,1.00, 4.69,0.78,1.00, 0,-1.25,0,   1.875,2.5,1.875
		cube = 4, 7.03,0.78,0.98, 7.03,0.78,0.98, 2.72,0.96,0.10, 2.72,0.96,0.10, 7.03,0.78,0.98, 7.03,0.78,0.98, 0,-1.875,0,  1.875,3.75,1.875
	}}
@PART[Tube2] {
	%DRAG_CUBE {
		cube = 0, 1.56,0.77,1.31, 1.56,0.77,1.31, 4.78,0.95,0.10, 4.78,0.95,0.10, 1.56,0.77,1.31, 1.56,0.77,1.31, 0,-0.3125,0, 2.5,0.625,2.5
		cube = 1, 3.12,0.77,1.31, 3.12,0.77,1.31, 4.78,0.95,0.10, 4.78,0.95,0.10, 3.12,0.77,1.31, 3.12,0.77,1.31, 0,-0.625,0,  2.5,1.25,2.5
		cube = 2, 4.68,0.77,1.31, 4.68,0.77,1.31, 4.78,0.95,0.09, 4.78,0.95,0.09, 4.68,0.77,1.31, 4.68,0.77,1.31, 0,-0.9375,0, 2.5,1.875,2.5
		cube = 3, 6.25,0.77,1.31, 6.25,0.77,1.31, 4.78,0.95,0.09, 4.78,0.95,0.09, 6.25,0.77,1.31, 6.25,0.77,1.31, 0,-1.25,0,   2.5,2.5,2.5
		cube = 4, 9.44,0.77,1.26, 9.44,0.77,1.26, 4.78,0.95,0.09, 4.78,0.95,0.09, 9.44,0.77,1.26, 9.44,0.77,1.26, 0,-1.875,0,  2.5,3.75,2.5
	}}
@PART[Tube3] {
	%DRAG_CUBE {
		cube = 0, 4.72,0.76,1.92, 4.72,0.76,1.92, 11.00,0.96,0.10, 11.00,0.96,0.10, 4.72,0.76,1.92, 4.72,0.76,1.92,  0,-0.625,0,    3.75,1.25,3.75
		cube = 1, 7.03,0.77,1.92, 7.03,0.77,1.92, 11.00,0.96,0.09, 11.00,0.96,0.09, 7.03,0.77,1.92, 7.03,0.77,1.92,  0,-0.9375,0,   3.75,1.875,3.75
		cube = 2, 9.44,0.77,1.92, 9.44,0.77,1.92, 11.00,0.96,0.09, 11.00,0.96,0.09, 9.44,0.77,1.92, 9.44,0.77,1.92,  0,-1.25,0,     3.75,2.5,3.75
		cube = 3, 14.06,0.77,1.92, 14.06,0.77,1.92, 11.00,0.96,0.09, 11.00,0.96,0.09, 14.06,0.77,1.92, 14.06,0.77,1.92, 0,-1.875,0, 3.75,3.75,3.75
		cube = 4, 18.75,0.77,1.90, 18.75,0.77,1.90, 11.00,0.96,0.10, 11.00,0.96,0.10, 18.75,0.77,1.90, 18.75,0.77,1.90, 0,-2.5,0,   3.75,5,3.75
	}
}
@PART[Tube4] {
	%DRAG_CUBE {
		cube = 0, 6.25,0.77,2.52, 6.25,0.77,2.52, 20,0.95,0.10, 20,0.95,0.10, 6.25,0.77,2.52, 6.25,0.77,2.52,   0,-0.625,0,   5,1.25,5
		cube = 1, 9.37,0.77,2.52, 9.37,0.77,2.52, 20,0.95,0.09, 20,0.95,0.09, 9.37,0.77,2.52, 9.37,0.77,2.52,   0,-0.9375,0,  5,1.875,5
		cube = 2, 12.5,0.77,2.52, 12.5,0.77,2.52, 20,0.95,0.09, 20,0.95,0.09, 12.5,0.77,2.52, 12.5,0.77,2.52,   0,-1.25,0,    5,2.5,5
		cube = 3, 18.75,0.77,2.52, 18.75,0.77,2.52, 20,0.95,0.09, 20,0.95,0.09, 18.75,0.77,2.52, 18.75,0.77,2.52, 0,-1.875,0, 5,3.75,5
		cube = 4, 25.00,0.77,2.52, 25.00,0.77,2.52, 20,0.95,0.10, 20,0.95,0.10, 25.00,0.77,2.52, 25.00,0.77,2.52, 0,-2.5,0,   5,5,5
	}
}
 

 

 

[KerikBalm]

On 1/23/2019 at 7:45 PM, bewing said:

As far as I'm concerned, clipping has never shielded anything from drag or heat,

I seem to recall that it works for heat, but not drag