tetryds

Official FAR Craft Repository

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Nixod321    48
2 hours ago, CrayzeeMonkey said:

There was no dihedral on the plane, but on turns I discovered that the wings had a tendency to flex up and cause a dihedral of some sort. A strut later it was reduced and the plane can turn much better now.

Thanks!

To save on weight you could also try adding a slight anhedral that will naturally flex up during high G-loading for better roll authority and droop down in level flight for better stability. It seems to work pretty well for fast-mover designs, it made my Mig-25 lookalike really nimble.

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9 hours ago, CrayzeeMonkey said:

There was no dihedral on the plane, but on turns I discovered that the wings had a tendency to flex up and cause a dihedral of some sort. A strut later it was reduced and the plane can turn much better now.

Thanks!

Dihedral effect isn't limited to dihedral wings(/lifting surfaces). A vertical surface (tail fin!) will also make your plane roll when slipping, as long as it's mounted above or below the CoM. If that wasn't the case, nearly every plane would have some dihedral, because you generally want a little dihedral effect (-> roll stability)

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capi3101    576
21 minutes ago, Cratzz said:

Hey, can someone tell me why this is stuck to the runway? Been doing this awhile, and it's happend before with some tweakscaled parts but this has none of that.

https://dl.dropboxusercontent.com/u/5191989/Untitled2.png

Where about is your CoM relative to the rear gears? Just curious. Also, my first instinct taking a look at this is that you've got some hellacious wing loading going on there.

Also curious as to what that control surface on the front of your wing does.

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Cratzz    5
3 minutes ago, capi3101 said:

Where about is your CoM relative to the rear gears? Just curious. Also, my first instinct taking a look at this is that you've got some hellacious wing loading going on there.

Also curious as to what that control surface on the front of your wing does.

Waay of i just noticed, i'll correct that and im probably fine. Wing loading? The control surface on the front acts as a canard and gets me of the ground.

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capi3101    576
26 minutes ago, Cratzz said:

Wing loading?

Ratio of the mass of the craft to the reference area of the wing. Higher wing loading tends to lend to better high-speed characteristics (particularly at low altitude), while lower wing loading lends itself to lower takeoff and landing speeds, better climb rate and cruise performance, and better sustained turning performance (in brief). My own self, I usually shoot for something in the 0.3-0.5 tonne per square meter range during my initial design calculations.

Edited by capi3101

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bzimac    5
17 hours ago, Cratzz said:

Hey, can someone tell me why this is stuck to the runway? Been doing this awhile, and it's happend before with some tweakscaled parts but this has none of that.

https://dl.dropboxusercontent.com/u/5191989/Untitled2.png

In addition to what was suggested above, maybe you should consider having bigger elevator (maybe put an all-moving tail for maximum control surface area).

About wing loading, you can get wing area from FAR window that you captured in screenshot. Just temporarily remove all wing surfaces except for actual wings (so, tail, rudder and all other moving horizontal components, since they normally don't give you any lift).

As for current state, with information from the picture, I would guess that it's around 600 kg/m^2, but i might be way off. That would still be flyable (I think I've made some stuff before that had about 750 kg/m^2), but it won't be easy to get off the runway.

Edit: looking at the burn time, now i realize that mass if probably much lower than what i thought (I assumed about 20 tons). In that case, simply being able to pull up on the runway should let it take off without any problem.

Edited by bzimac

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Deizelpunk    52

Fellas i've made a grand accomplishment for myself tonight, Vanilla folding wings! Looks ugly as hell but I'm so happy with them! Aircraft carrier here I come! I must stress its ugly, and I dont like the awkward angle the wings sit at while up, but it works! Good ol vernor engines in the little pods on the wingtips, then under the wing part on the fuselage I made a little hinge that the wing uses to rotate up! Hardest part was getting the docking ports lined up, but trial and error does the job! http://i.imgur.com/FiNxvr8.jpg 

Ok how the hecc do I insert pictures into my post? I really wanna show this thing off!

 

Edited by Deizelpunk

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kcs123    467
1 hour ago, Deizelpunk said:

Ok how the hecc do I insert pictures into my post? I really wanna show this thing off!

On bottom right corner there is "Insert other media" combobox. Click on it and choose "Insert image from URL". Other way is to copy-paste image link directly in post but you need to choose option to keep formating, not cancel it. Obviously it not always work as intended.

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Deizelpunk    52
23 minutes ago, kcs123 said:

On bottom right corner there is "Insert other media" combobox. Click on it and choose "Insert image from URL". Other way is to copy-paste image link directly in post but you need to choose option to keep formating, not cancel it. Obviously it not always work as intended.

Hmmmmm doesent work for me

 

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Cratzz    5

Working on F4 Phantom, apart from having a little bit too much positive AoA, she flies well! Tried too be as true too the reallife counterpart as possible, so lenght/width/height/drymass/wetmass etc is mostly correct.

I recently learn about Area Ruling, don't know if that was a thing in the 50's, but did too nonetheless :) There are some more issues im not quite happy with (like the intake) but im saving that for Rev. 2! :wink:

https://dl.dropboxusercontent.com/u/5191989/F4.3.png

https://dl.dropboxusercontent.com/u/5191989/F4.2.png

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19 minutes ago, Cratzz said:

I recently learn about Area Ruling, don't know if that was a thing in the 50's

Was a thing in Germany even before 1945. Wing sweep as early as the thirties. Allies should have known about wingsweep too, considering it wasn't kept a secret. They did, however, ignore any knowledge they may have had about it, until they found German blueprints and a prototype (or several prototypes?).

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Cratzz    5
10 hours ago, FourGreenFields said:

Was a thing in Germany even before 1945. Wing sweep as early as the thirties. Allies should have known about wingsweep too, considering it wasn't kept a secret. They did, however, ignore any knowledge they may have had about it, until they found German blueprints and a prototype (or several prototypes?).

Ones again does war prepel science, thanks for the input!

Phantom Mark 2, complete redesign (cause why not) New intakes and better balanced. SPACE-program? Bah! Jets are much more appealing :)

F4.Mark.2.png

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Btw: SpaceDock says that FAR is still outdated. Does the outdated version work with the latest KSP patch? Or are you using some experimental branch?

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Svm420    263
5 hours ago, FourGreenFields said:

Btw: SpaceDock says that FAR is still outdated. Does the outdated version work with the latest KSP patch? Or are you using some experimental branch?

its the dev version. Use at your own risk. Don't bug ferram! :wink:  That sort of thing.

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Elmetian    78
Posted (edited)

I finally gave up waiting for an official release of FAR, installed the supersecret dev version and built this, a (re)creation of Sukhoi's planned T-4MS "200" partially-stealthy supersonic strategic bomber from the late 1970s. Click on the gif below to link to an imgur album with loads of background information about the real thing, as well as some of my craft's specs and the mods I used.

kGZU7y1.gif

And here's a video showcasing what it can do. Unfortunately BDArmory Continued doesn't play nicely with any of the nuclear weapon mods, so I couldn't show you what it's really designed for: dropping nuclear weapons from high altitude while moving at mach 3. Even with 20+ km of separation, the blast always destroys the aircraft.

 

Edited by Elmetian

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Hodo    400

Just here to say... I aint dead yet.

 

0i3eAVR.jpg

xgApODW.jpg

alFP9bn.jpg

0yRA9lF.jpg

 

Using FAR, BD Armory, and AJE.  I still got it... a bit rusty but can STILL make SSTOs.

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Hodo    400

And back to making combat aircraft...

 

F-114

ir0jTU6.jpg

SD2q7gM.jpg

1nBXjHM.jpg

 

Fast, agile, inexpensive, and has supercruise. 

What else can you ask for out of a single engine light fighter.

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Nixod321    48

Here are all of my best and most original aircraft designs so far. It seems that i'll have to give up on this save however, as it is an older version and wow is it laggy. There are about 128 separate aircraft saved in the SPH alone. It takes three minutes just to load the craft list.

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I'm currently having a problem with some of my planes concerning (mostly) low speed control.

While trying to make tight turns at speeds less than 150m/s, the highest wing in the turn starts stalling and the plane jerks to the direction opposite of the turn (Like the FW 190 when you try to push it too hard). Why does it do this? How can the wings stall at different times during a turn? Is there any way to prevent this from happening?

Plane I'm currently working on, also has this problem at low speeds.

QZupN2J.jpg

Graphs if anyone is interested.

-5 to 50 AoA Sweep at Mach .3

-5 to 50 AoA Sweep at Mach .3 and Pitch Setting 1

Wing loading (mass according to engineer's report / reference area in stability derivatives window): 15 t/m^2

Thanks in advance!

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Posted (edited)
3 hours ago, CrayzeeMonkey said:

I'm currently having a problem with some of my planes concerning (mostly) low speed control.

While trying to make tight turns at speeds less than 150m/s, the highest wing in the turn starts stalling and the plane jerks to the direction opposite of the turn (Like the FW 190 when you try to push it too hard). Why does it do this? How can the wings stall at different times during a turn? Is there any way to prevent this from happening?

Plane I'm currently working on, also has this problem at low speeds.

*screenshot*

Graphs if anyone is interested.

-5 to 50 AoA Sweep at Mach .3

-5 to 50 AoA Sweep at Mach .3 and Pitch Setting 1

Wing loading (mass according to engineer's report / reference area in stability derivatives window): 15 t/m^2

Thanks in advance!

Am I right to assume it only reaches critical AoA due to thrust vectoring?

 

Either way, my money is on side-slip, and possibly higher speed of the outer wing.

Considering you compared it to the 190, I assume that you know it's a bad idea to pull hard when using rudder, and afaIk that's because the side-slip causes asymmetric stalls. And you'll usually end up with a small amount of side-slip in turns, unless you counter with rudder.

Also the outer wing has a slightly larger turn-radius (unless banked 90°), while keeping the same turn-time, with other words a higher speed. If your wings stall sooner at higher speed, it may make matters worse.

 

PS: How stable is the dev-version of FAR?

Edited by FourGreenFields

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Nixod321    48
Posted (edited)
6 hours ago, CrayzeeMonkey said:

I'm currently having a problem with some of my planes concerning (mostly) low speed control.

While trying to make tight turns at speeds less than 150m/s, the highest wing in the turn starts stalling and the plane jerks to the direction opposite of the turn (Like the FW 190 when you try to push it too hard). Why does it do this? How can the wings stall at different times during a turn? Is there any way to prevent this from happening?

Plane I'm currently working on, also has this problem at low speeds.

 

Graphs if anyone is interested.

-5 to 50 AoA Sweep at Mach .3

-5 to 50 AoA Sweep at Mach .3 and Pitch Setting 1

Wing loading (mass according to engineer's report / reference area in stability derivatives window): 15 t/m^2

Thanks in advance!

Generally the modern fast-mover designs like the su-27 and f-14 your aircraft resembles do not have good low speed handling due to the high wing loading (15t/m² is crazy high, even the biggest fighter jets have about 500kg/m2 with full fuel) and the drag inducing vortices formed at high AoA. The swept wings your design exhibits can also induce asymmetric stalls due to tip stalling.

Like the user before me said, the wings are hitting the air at different speeds and different angles, causing different boundary layer behavior. Generally in aircraft without swept wings you will see the bases of the wings stall first, before the roots, causing the entire wing to quickly stall in succession.This is why too much AoA in planes like the fw190 (which has big square wings) will cause this sort of stalling problem.

This problem can be mitigated by adding wing rakes, fences or vortex generators, to ensure the whole wing stalls evenly but those will limit your performance a bit. 

You might be able to eliminate this problem with a variable camber wing, as it is what most modern jet fighters use to reduce landing speeds. Play around with replacing both the leading and trailing edges with flaps/flaperons and experiment in using the %AoA function to activate them.

You can probably also significantly improve the aircraft's performance in a turn by tapering the wings.

Edited by Nixod321

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Cratzz    5
F14

Jebediah complained about too much positive AoI, making his arms hurt after hammering the stick to keep it from going nose up at certain speeds. So it needs some work. But it's my first craft with variable wings, and IR. So much fun! Wobbles pretty bad though, but im working on building a sturdier variant that works more like the real thing below. Pics when!

hwIm8.gif

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2 hours ago, Cratzz said:

Jebediah complained about too much positive AoI, making his arms hurt after hammering the stick to keep it from going nose up at certain speeds. So it needs some work.

Or just trim the plane (iIrc alt + qweasd, and alt + x removes trim).

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