[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18

[Citizen247]

21 hours ago, Ninadragonborn said:

can please some one help me its not a crash this mod just make every elevon inverted

i am polaying in RSS

should i place the list of mod i am playing

 

Usually, the reason for the reversal of pitch control is the location of the control surface compared to the COM. I've noticed that on some craft the COM can be further back than in stock, not sure why. However, it's worth checking if that's your problem. Try moving the control surface back, and checking where the COL and COM are.

[Ninadragonborn]

1 minute ago, Citizen247 said:

Usually, the reason for the reversal of pitch control is the location of the control surface compared to the COM. I've noticed that on some craft the COM can be further back than in stock, not sure why. However, it's worth checking if that's your problem. Try moving the control surface back, and checking where the COL and COM are.

now that's make thing complicated because in hanger i always place COM behind COL and see them in hanger so they are in right position and now as you said it could be behind  what is shown in hanger

also i am playing in RSS

this is really getting complicated i think soon i need an expert in aerodynamic and physic to make things right

i have forgotten the FAR also makes my fairing create lift which makes rockets top creating lift toward east as soon as i start the gravity turn and as i get more into toward east the more lift is created which makes rocket turn down easily and makes flying it really hard until i reach above 30 KM and the atmosphere is weak

 

[Citizen247]

1 minute ago, Ninadragonborn said:

now that's make thing complicated because in hanger i always place COM behind COL and see them in hanger so they are in right position and now as you said it could be behind  what is shown in hanger

also i am playing in RSS

this is really getting complicated i think soon i need an expert in aerodynamic and physic to make things right

8

If the COL is in front of the COM the plane with be statically unstable. This is sometimes done in fly-by-wire aircraft in the real world because it makes them more manoeuvrable. In general, though you want to place the COL just behind the COM. What I meant though was that when Elevons are reversed it's because they are too near or in front of the COM.

With FAR what you see in the hangar should be correct. I meant the same craft in FAR can have a COM that is further back than it does in stock. This might be why the elevons are reversed in FAR but not stock.

8 minutes ago, Ninadragonborn said:

i have forgotten the FAR also makes my fairing create lift which makes rockets top creating lift toward east as soon as i start the gravity turn and as i get more into toward east the more lift is created which makes rocket turn down easily and makes flying it really hard until i reach above 30 KM and the atmosphere is weak

4

Yep, FAR produces body lift. Try to make sure the COM is toward the bottom of the rocket. Keep the rocket within the AOA on the nav-ball, moving too far off the direction of travel is going to cause the rocket to flip.

In RSS I generally try to keep the initial TWR as about 1.25 on the pad. Definitely no higher than 1.3 and no lower than 1.2. Launch straight up until you hit around 90-100m/s, then pitch to around 80 degrees. Once the AOA indicator is back on your nose, just set SAS to follow it and let the rocket fly itself. You should be hitting around 1000m/s at 45 degrees.

By that time you should be high enough that you can do adjustments without having aerodynamic issues.

[Ninadragonborn]

1 minute ago, Citizen247 said:

If the COL is in front of the COM the plane with be statically unstable. This is sometimes done in fly-by-wire aircraft in the real world because it makes them more manoeuvrable. In general, though you want to place the COL just behind the COM. What I meant though was that when Elevons are reversed it's because they are too near or in front of the COM.

With FAR what you see in the hangar should be correct. I meant the same craft in FAR can have a COM that is further back than it does in stock. This might be why the elevons are reversed in FAR but not stock.

Yep, FAR produces body lift. Try to make sure the COM is toward the bottom of the rocket. Keep the rocket within the AOA on the nav-ball, moving too far off the direction of travel is going to cause the rocket to flip.

In RSS I generally try to keep the initial TWR as about 1.25 on the pad. Definitely no higher than 1.3 and no lower than 1.2. Launch straight up until you hit around 90-100m/s, then pitch to around 80 degrees. Once the AOA indicator is back on your nose, just set SAS to follow it and let the rocket fly itself. You should be hitting around 1000m/s at 45 degrees.

By that time you should be high enough that you can do adjustments without having aerodynamic issues.

sorry my mistake it should be like this COL behind COM its what i always do like this i always do it i am playing kerbal for over 3 years now but just started playing in RSS in past 10 months ago and it was nice until i realized its not realistic just like ksp imaginary sol system 

the sol of RSS is right but many physic it seems are not

so i decided to use this mods a lot of mod

and it seems there i can't find the reason behind all this problems  

and as you can see in this picture it create downward lift no matter what i do

i think i should try your configs

do they work in RSS with all planet

[Citizen247]

12 minutes ago, Ninadragonborn said:

and as you can see in this picture it create downward lift no matter what i do

2

To somewhat simplify the issue: that's normal. A tailplane should be producing downforce. Doing so pushes the tail down and keeps the nose up, basically. If you're not getting enough lift try moving the tailplane back, increasing your wing size and/or reduce the weight of the plane. It's hard to tell but your landing gear might be a bit far back. You can also give your main wings positive angle of attack.

[Ninadragonborn]

19 minutes ago, Citizen247 said:

To somewhat simplify the issue: that's normal. A tailplane should be producing downforce. Doing so pushes the tail down and keeps the nose up, basically. If you're not getting enough lift try moving the tailplane back, increasing your wing size and/or reduce the weight of the plane. It's hard to tell but your landing gear might be a bit far back. You can also give your main wings positive angle of attack.

    i have taken this picture while playing with FAR and AJE and Your configs for airplane plus is this right the elevon creating down ward and wing up ward

this is from FAR analysis

[Ninadragonborn]

this is data from flight

[Ninadragonborn]

@Citizen247 could you give me the configs  you said earlier for atmosphere i think FAR is not working for me thanks 

Edited December 27, 2017 by Ninadragonborn

[Citizen247]

5 hours ago, Ninadragonborn said:

@Citizen247 could you give me the configs  you said earlier for atmosphere i think FAR is not working for me thanks 

I don't think you're having problems with FAR, I think it's your design that's at issue. Your wings are too far back, there's too much weight at the back and not enough at the front. Also, the aircraft is flying...

[Ninadragonborn]

1 hour ago, Citizen247 said:

I don't think you're having problems with FAR, I think it's your design that's at issue. Your wings are too far back, there's too much weight at the back and not enough at the front. Also, the aircraft is flying...

i have removed both AJE and FAR

i have done all sort of things big plane small plane long wing no matter what i do it still create down ward lift i am using normal atmosphere in RSS 

and it seems fine except some engine have a lot of thrust but i have fond out many the atmosphere in RSS is realistic enough not 100 present but 80% because you can get more then 1100 km/h from a turbofan engine with out afterburner and also as i get higher the thrust also drop fast enough like real world so i decided to let go of these mod and play with other 134 mod i have installed

anyway thanks

[Citizen247]

10 hours ago, Ninadragonborn said:

i have removed both AJE and FAR

i have done all sort of things big plane small plane long wing no matter what i do it still create down ward lift i am using normal atmosphere in RSS 

and it seems fine except some engine have a lot of thrust but i have fond out many the atmosphere in RSS is realistic enough not 100 present but 80% because you can get more then 1100 km/h from a turbofan engine with out afterburner and also as i get higher the thrust also drop fast enough like real world so i decided to let go of these mod and play with other 134 mod i have installed

anyway thanks

I'll send you a PM with atmosphere settings I use in stock for you to try.

[Citizen247]

I'm trying to add FAR configs to some of the control surfaces in Airplane Plus but one isn't working, with a really strange problem.

This oval winglet:

Seems to work fine with this config:
 

@PART[roundwinglet]:FOR[FerramAerospaceResearch]
{
	@module = Part
	@maximum_drag = 0
	@minimum_drag = 0
	@angularDrag = 0
	@dragCoeff = 0
	@deflectionLiftCoeff = 0
	@ctrlSurfaceRange = 0
	@ctrlSurfaceArea = 0
    	!MODULE[ModuleLiftingSurface] {}
    
	MODULE
	{
		name = FARControllableSurface
		maxdeflect = 15
		MAC = 1.35
		MidChordSweep = 0
		b_2 = 1.6
		TaperRatio = 1
		ctrlSurfFrac = 0.82
	}
}

This doesn't seem to work though:

@PART[warhawkfin]:FOR[FerramAerospaceResearch]
{
	@module = Part
	@maximum_drag = 0
	@minimum_drag = 0
	@angularDrag = 0
	@dragCoeff = 0
	@deflectionLiftCoeff = 0
	@ctrlSurfaceRange = 0
	@ctrlSurfaceArea = 0
    	!MODULE[ModuleLiftingSurface] {}
    
	MODULE
	{
		name = FARControllableSurface
		maxdeflect = 15
		MAC = 1.925
		MidChordSweep = 0
		b_2 = 2.7
		TaperRatio = 0.48
		ctrlSurfFrac = 0.857
	}
}

The stock settings remain in the hangar, the control surface doesn't move in flight and for some reason, SAS and Atmosphere Autopilot take it upon themselves to cause any aircraft using it as a rudder to yaw massively...

Remove the FAR config and these problems vanish, though obviously the wing is then not configured to work properly with FAR.

I had to guess at some of the values in the config because the images in the "Deriving FAR values for a wing using Blender 2.7" for deriving the values seems to be gone. Could incorrect values cause this?

Edited December 28, 2017 by Citizen247

[eberkain]

AVC was telling me that I have an out of date version, but I just downloaded it yesterday.  So I went and redownloaded the latest release from github and sure enough the version file included in that says 15.8.1 but the version file on github is updated to 15.9 and was last modified the same day as the release...  Is it safe to just pull a copy of the master zip and use that to install?

[Drew Kerman]

3 hours ago, Citizen247 said:

I had to guess at some of the values in the config because the images in the "Deriving FAR values for a wing using Blender 2.7" for deriving the values seems to be gone. Could incorrect values cause this?

??? I just checked and I don't notice any missing. They are hosted on my server tho and it could have been down for a little bit when you happened to look at the tutorial

[Citizen247]

3 minutes ago, Drew Kerman said:

??? I just checked and I don't notice any missing. They are hosted on my server tho and it could have been down for a little bit when you happened to look at the tutorial

This is what I'm seeing:

Fitting and Swept wing approximation don't show. Everything else seems too. 

[Drew Kerman]

Just now, Citizen247 said:

Fitting and Swept wing approximation don't show. Everything else seems too. 

Yup you're right, completely missed that

[The-Grim-Sleeper]

I am having some trouble, but I'm not sure if it's due to a bug or because I derped on the key feature of FAR.

When designing an aircraft in the SPH, the Centre-of-Lift ball will have no arrow, does not update in real-time with the placement of parts, and no amount of wing surface seems to move it very far in any direction, except when I place the wings higher and somehow ends up below the Centre-of-Mass!

So now I have a set of aircraft that turned into wind-vanes by FAR, but I can't really work out how to fix them. I looked at the Ferram tool (the toolbar button in the SPH), but couldn't gather much from it. I thought that the blue and yellow lines are CoL and CoM resp, but looking at the whole 1 page of info on git just informs me that it is not.

Is there any sort of comprehensive guide to 'not making a brick/tissue-hybrid'? Or at least an explanation of what information is in the FAR-tool and why that info is relevant for aircraft-design?

Link to .craft: https://drive.google.com/open?id=1zDA1o6Up0MDcRNq-RfXFiq-LoU1eGe9j

(uses firespitter, carrier accessories and infernal robotics)

Edited December 31, 2017 by The-Grim-Sleeper

[lordcirth]

4 hours ago, The-Grim-Sleeper said:

I am having some trouble, but I'm not sure if it's due to a bug or because I derped on the key feature of FAR.

When designing an aircraft in the SPH, the Centre-of-Lift ball will have no arrow, does not update in real-time with the placement of parts, and no amount of wing surface seems to move it very far in any direction, except when I place the wings higher and somehow ends up below the Centre-of-Mass!

So now I have a set of aircraft that turned into wind-vanes by FAR, but I can't really work out how to fix them. I looked at the Ferram tool (the toolbar button in the SPH), but couldn't gather much from it. I thought that the blue and yellow lines are CoL and CoM resp, but looking at the whole 1 page of info on git just informs me that it is not.

Is there any sort of comprehensive guide to 'not making a brick/tissue-hybrid'? Or at least an explanation of what information is in the FAR-tool and why that info is relevant for aircraft-design?

Link to .craft: https://drive.google.com/open?id=1zDA1o6Up0MDcRNq-RfXFiq-LoU1eGe9j

(uses firespitter, carrier accessories and infernal robotics)

The CoL icon is not used by FAR; aero isn't that simple.  As for the derivatives window, if you see red, hover over it and read what it says.  For example, Mw being green is the equivalent of "CoL behind CoM".  If I recall correctly, it says something like "change in pitch with regard to pitch", or something like that, ie, does pitching up make you pitch up more.

[The-Grim-Sleeper]

20 minutes ago, lordcirth said:

Some tips

Thank you.

Well, I've discovered the 'Calulate Stability Derivatives'-Button, that is good.

So Mw warns "about CoL behind CoM", but there are 33 other values there, none of which where red when I deliberately made a lawn-dart.

Example: when I made a craft and the L_β was red and helpfully informed me that "Change in Roll-Right angular acceleration with respect to sideslip angle β; should be negative". I have no idea what that means. I did notice that I had left the mirror symmetry off, and the craft only a left-side wing.

I really should have googled my problem: "comprehensive-ferram-aerospace-research-tutorial/"

[Papichulo2018]

Should the Part G-Force Limit, Part Pressure Limit, Kerbal G-force Limit be turned on? 

Thanks

[Drew Kerman]

3 hours ago, Papichulo2018 said:

Should the Part G-Force Limit, Part Pressure Limit, Kerbal G-force Limit be turned on? 

Thanks

the first breaks things if you pull high Gs, the second breaks things if you fly too fast and build up air pressure, and the third affects kerbal's livelyhood if you put them in high-G situations.

They are options, so decide whether you want any of these things and enable/disable as you desire.

[yknooble]

Hi all! 

I need some help with some aero force asymmetry. I have a perfectly symmetrical plane with one intake, and one thruster, so asymmetric thrust is probably not the issue. This issue is also intermittent. I've uploaded the craft file, and some images.

KSP version	1.3.0
FAR verision	0.15.9 Liebe
Other mods	AFBW, VesselView, JSI, KIS, KAS

Craft file: https://drive.google.com/open?id=12ky25EgSyq17K4aUO7eKi3H64fidhuoC

This issue also occurs for the FAR craft, and it happens intermittently on launch reverts.

 

This is the craft functioning properly. 

https://drive.google.com/open?id=1r4SUu1KT7CNOnFPv5378zy9-kQVJ4a_K

 

Here the asymmetric forces appear.

https://drive.google.com/open?id=1iWmvX9N4dVmahuMx-ZWampzJimBO-C9t

 

note that at the moment those two images are taken, I am not providing any input for control.

note also the yaw drift, the roll compensation in the staging panel, and the aero force on the craft.

Edited January 6, 2018 by yknooble
far version corrected

[Drew Kerman]

7 hours ago, yknooble said:

I need some help with some aero force asymmetry

How much tweaking have you done on the craft to get good flight characteristics to show up in the FAR analysis window. I know that for one recent plane I designed it had a weird tendency to roll left for no good reason that I could see. When I completely and carefully rebuilt the whole thing, I had no more issues and it flew great. I know the prospect of a complete rebuild is... not fun, but sometimes in the process of adding, removing, translating, rotating, undoing, reloading and all the rest, something may have gotten a little messed up somewhere.

Hopefully others have better ideas but if all else fails...

[Maeyanie]

17 hours ago, yknooble said:

note that at the moment those two images are taken, I am not providing any input for control.

note also the yaw drift, the roll compensation in the staging panel, and the aero force on the craft.

It looks from the control position that the SAS is giving some left roll in the second shot, which should give you higher lift on the right side. It's not all that far to the left, though, so not sure if that's enough to cause the difference to be that large.

It's hard to see exactly how the aircraft is built in those shots, but I'm not seeing any sort of rudder or other yaw stabilization, which would lead to it being unstable. That could be at least some of your problem.

None of that explains why it would be intermittent, though.

[yknooble]

16 hours ago, Drew Kerman said:

How much tweaking have you done on the craft to get good flight characteristics to show up in the FAR analysis window. I know that for one recent plane I designed it had a weird tendency to roll left for no good reason that I could see. When I completely and carefully rebuilt the whole thing, I had no more issues and it flew great. I know the prospect of a complete rebuild is... not fun, but sometimes in the process of adding, removing, translating, rotating, undoing, reloading and all the rest, something may have gotten a little messed up somewhere.

Hopefully others have better ideas but if all else fails...

All the stability derivatives are in the green. I've also ensured the center of lift is to the rear of the center of mass.

To be clearer, 

23 hours ago, yknooble said:

This is the craft functioning properly. 

https://drive.google.com/open?id=1r4SUu1KT7CNOnFPv5378zy9-kQVJ4a_K

 

Here the asymmetric forces appear.

https://drive.google.com/open?id=1iWmvX9N4dVmahuMx-ZWampzJimBO-C9t

these images were taken on separate launches, and on these separate launches, the craft performance is very different.

Quote

It's hard to see exactly how the aircraft is built in those shots, but I'm not seeing any sort of rudder or other yaw stabilization, which would lead to it being unstable. That could be at least some of your problem.

There is no rudder, but it flies fine without it on some launches, and flies terrible anyway when i do add a rudder on other launches

Edited January 7, 2018 by yknooble