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

[federicoaa]

Hi Ferram4, I noticed that when you use the flight assistant it remains on when you switch ships. Flight assistant is good for planes but for rockets it may cause lot of undesirable movements, even while in space my rockets go like crazy, but only when SAS is off and the flight assistant options are on.

I would suggest to deselect all the FA options when the ship loads by default, that'll avoid some headaches I'm sure XD.

Besides, the FA controlling the ship outside the atmosphere should be a bug right?

[Chestburster]

I've encountered a small problem with FAR and flaps

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The lift is starting to raise and fall multiple times per second when i deploy the flaps, making the craft roll (its more a stutter) clockwise. I've tried to reposition them but nothing solved the problem. So.. what is causing this?

[a.g.]

That's a symptom of raycasts that it does to find if it is behind a wing intermittently failing, although I have only encountered that with spoilers attached to the top of the wing before. I have already sent a patch to Ferram that adds a special case for control surfaces structurally attached to a wing, which should hopefully fix this kind of thing.

[Boamere]

So how would I go about getting this reading into the green?

This is on an average delta-wing spaceplane with large flaps

Edit:Just tested it and I get almost no pitch control when I enter mach 1+

Why am I getting such a severe Mach-tuck?

(also getting negatives in the Zu direction)

Edited February 7, 2014 by Boamere

[thufir]

I'm having issues with FAR in a new install. How do I get an output log for you?

[ferram4]

@Boamere: Normally you can ignore Xw and Zu if the magnitudes are small enough. I'd guess that your issues stem from the plane being too stable, since that's normally the cause of losing control at supersonic Mach numbers.

@thufir: What issues are you having? Try uploading the output_log.txt from KSP_Data to a pastebin or dropbox after you cause the issue in-game.

[Agathorn]

Here you go

https://www.dropbox.com/s/oxc7homerzv008k/Delta%20Rapier.craft

Action groups:

1 - lower flaps (for take off / slow landing)

2 - raise flaps (once airborne)

3 - switch engines mode

You need the following mods: B9, Procedural wings, Magic Smoke Infernal Robotics (for the rotating dock in the cargo, i can remove it if you want). And of course FAR.

Enjoy !

Thanks! /10.

[Boamere]

@Boamere: Normally you can ignore Xw and Zu if the magnitudes are small enough. I'd guess that your issues stem from the plane being too stable, since that's normally the cause of losing control at supersonic Mach numbers.

@thufir: What issues are you having? Try uploading the output_log.txt from KSP_Data to a pastebin or dropbox after you cause the issue in-game.

Too stable? Now that's something I've never heard of before!

Thanks!

Did some more testing, it doesn't like pitching up, but if i turn it sideways and yaw, it pitches up fine

Edited February 8, 2014 by Boamere

[Zuni]

Do swept wings reduce drag at transonic speed with this?

[ferram4]

@Boamere: I think our definitions of "average delta-wing spaceplane with large flaps" are very different. You'll need to post a picture if you want any further suggestions.

@Zuni: Yep! And at supersonic speeds as well!

[Boamere]

Meh, I will when I go back on ksp

[federicoaa]

Are there any guidelines for using winglets in rockets with FAR? They usually transform my rocket into a dart that cannot be moved from the prograde vector XD, and sometimes it makes the rocket spin out of control.

[AbeS]

You may be doing your gravity turn way to late. Gradually turn eastwards (or wherever you wanna go) after you reach a velocity of about 100 m/s, which should be around 500 m (varies with the rocket). Also make sure that your TWR at launch is around 1.2-1.6

[NathanKell]

500m? Dang, you folks use high TWR rockets! With my 1.2TWR it takes me until 1.5km to get up to 100m/s!

But yeah, the main point is to start your turn early. But you really shouldn't need fins unless your rocket is seriously unstable, and you certainly shouldn't be needing them for control.

[Surefoot]

I use fins if i have a large payload inside fairings, to balance the drag. Otherwise nothing is better...

[DaMichel]

Hey guys,

i wanted to show my first cargo spaceplane. It is designed to bring 36 t into LKO.

This is the first version which reached orbit. The supersonic transition was very difficult to overcome. The craft has a forward fuel tank and two rear tanks, one of which is empty. When mach tuck sets in, i pump the fuel from the forward to the empty rear tank. Otherwise i couldn't get it to be stable in all flight regimes. The control surfaces are already quite large but on their own they are still not enough.

Problems:

* I have to trim for left yaw and roll ... hold on ... i just spotted messed up asymmetrical strutting ... that is perhaps the reason.

* Some sort of Dutch Roll when it started accelerating under rocket mode. I think i solved this one by mounting the wings lower, giving it less roll restoration force. Right? The next version is a lot more stable.

* Take off. It must use the end of the runway because just cannot pitch up enough without tail striking. I should use the large B9 Gear instead of stock to give it enough clearance. To do.

Mark 3:

Lower mounted wings. In addition to less roll oscillations, the engines on the nacelles give it an pitch-up torque, which is nice to have.

Has slightly smaller and more swept wings and vertical stabilizers. I probably also fixed the strutting. Overall it behaves very well. Only, for some reason i still have to trim for a little bit of yaw.

This game brings out the nerd in me like nothing else ...

Edited February 9, 2014 by DaMichel
wording

[prullenbak]

FAR also has trouble working together with planet mods like Abaddon for example. Apparently there is some kind of library error or conflict or something like that.

[DaMichel]

I think i found a bug. The CoL is off to the side here.

[Surefoot]

@DaMichel: Delta wings FTW ! You'll need less struts using KJR, and one-piece wings, the outer part of your deltas wont need 3 pieces unless you are adding some polyhedral (cannot see on the screenshots here). As for mach tuck, i noticed with the right delta profile it goes away almost completely. Try and assign the control surfaces to just one axis, it helps (especially pitch / roll). I usually assign yaw purely to vertical tails. With such a swept wing profile you'll need flaps for takeoff, since you have a tailless design you can use leading edge slats, they are quite efficient on this kind of design.

[DaMichel]

@DaMichel: Delta wings FTW ! You'll need less struts using KJR, and one-piece wings, the outer part of your deltas wont need 3 pieces unless you are adding some polyhedral (cannot see on the screenshots here).

I cannot play without KJR. It is awesome. But without some struts it is too wobbly. The wings have to carry about 100 t weight after all

Yeah i should replace the outer two pieces. But can i mount the nacelle without splitting the wing in two pieces?

As for mach tuck, i noticed with the right delta profile it goes away almost completely.

I didn't have much luck with this. Thanks for the tip though. I'll keep it in mind.

Try and assign the control surfaces to just one axis, it helps (especially pitch / roll). I usually assign yaw purely to vertical tails.

Sure, always!

With such a swept wing profile you'll need flaps for takeoff, since you have a tailless design you can use leading edge slats, they are quite efficient on this kind of design.

Thanks. I will give it a try. Till now i always considered flaps as a luxury which is not really needed. At least in KSP

[brusura]

Is there some bug with engine nacelle? I used 2 ram air in front of 2 engine nacelle, when I have engine nacelle open the plane start to yaw and roll and if I do not close them I flip off

ps: i use action group 3 for ram air and 4 for engine nacelle , I have checked and they are set correctly no asimmetry with drag with one close and one open

[ferram4]

@prullenbak: That's the fault of the planet pack maker. They're supposed to set the flightGlobalsIndex for each planet to a unique number, but they're not, which causes the error. Bring it up with them, not me.

@brusura: That sounds like intended behavior. You probably don't have a large enough vertical tail. All of those are signs that the plane doesn't have enough yaw stability, and if all of your intakes are at the front of the plane then they will make the plane less stable.

[brusura]

Hi ferram4, I guess it is the second, all of my intakes are in the front, but I would expect more pitch difficulty than roll and yaw ( from my very limited knowledge of aerodinamic ) , I traded the engine nacelle with two small rocket fuel tank, the following image is the craft in orbit ( I guess that is large enough vertical tail ) :

http://imgur.com/6RWFip2

[Surefoot]

Yeah i should replace the outer two pieces. But can i mount the nacelle without splitting the wing in two pieces?

You'll need 2 pieces indeed, no choice here. One option with that many engines could be mounting engines on upper / lower nacelles, above and below the wing so you get 1 piece wings.. I have been toying with that a lot

Till now i always considered flaps as a luxury which is not really needed. At least in KSP

Same here, when you reach optimal designs for supersonic you notice they are all quite arrow-shaped and at low speed they fly like bricks

@brusura: your vertical tails are way too small...

[ferram4]

@brusura: Barely large enough vertical tail there. I'd expect to get issues with that at high speeds to be honest.