Official FAR Craft Repository

[Van Disaster]

Hm, variable geometry makes no detectable difference subsonic ( I thought it should make *some* difference - maybe I need a bigger craft ), but it's a very good illustration of wing shape when you're supersonic.

For people browsing who don't know FAR, there's drag coefficient and current actual drag in the big panel on the left.

[Hodo]

I know that I had this discussion with Farrem4 before in the FAR thread.  He said since the voxel addition it updates with the voxels and the FAR drag calculations.   I am not sure how fast it does this but I imagine it is pretty fast, because if you drop drop tanks from the craft it will change the drag numbers.  And if you setup the aircraft so the CoL is close to the CoM on the craft at subsonic flight and it is twitchy at low speeds, you sweep the wings back it actually becomes a different flight profile.  I have tested this on a few craft I have made with the variable geometry wings. I may do more testing tonight or this weekend.

[kcs123]

@Van Disaster, even on your picture is actualy noticable difference with folded and extended wings. When you look at only lift or drag, it might not see big changes, but look at L/D ratio, it is noticable difference. Whole craft is much more efficient with swept wing. Main purpose of swept wing is not only to have less drag on supersonic speeds, some ordinary craft with swept or delta wings might perform much better on supersonic velocity, but such craft have usualy high take off / landing speed and require longer runway. Like @Hodo said, craft with variable geometry wings performs much better if you place COL very near COM. In some cases COL might be just lightly in front of COM when aircraft heve fully extended wing position. Combined with flaps and good engine gimbals you can put backfliping under control with such settings.

Even when your rear elevator wing stalls, craft can be controled with engine gimbals and you can land aircraft almost like a VTOL. Such thing is more important when you have runway of limited length or to perform landing on aircraft carrier, for example.

Anyhow, following @varsass tips, I have improved IR Foldable system even further. Created nice airplane with this that performed in flight even better than expected.
Here is another small album showing progress and and flight test results.

 

 

[Van Disaster]

Those shots were supersonic - the point was to illustrate how wing shape matters for supersonic craft high subsonic I get no perceptable change in anything except pitch...

[kcs123]

I just uploaded several crafts with variable geometry wings. It actualy work better than even expected. Here is link for download if someone wants to try them. I have also included assembly that can be used on different crafts as you need them.

 

[eightiesboi]

Hey all,

I could really use some input. After watching the YouTube tutorial and reading the wiki, I decided to take a stab at FAR in my new career. I built a craft that I *believe* should be stable, but I start bouncing all around the runway long before takeoff. Can someone with a brain take a look and give me a suggestion as to what I've screwed up? Craft file should be all stock, and it represents the best parts I can get at this point in my career. I am also more than willing to accept any advice, pointers, or potatoes--whatever you've got to throw in my direction.

https://onedrive.live.com/redir?resid=FE34D6542466878C!318466&authkey=!ALLoeYpqtnw8UY4&ithint=file%2ccraft

Thanks!

[FourGreenFields]

17 minutes ago, eightiesboi said:

Hey all,

I could really use some input. After watching the YouTube tutorial and reading the wiki, I decided to take a stab at FAR in my new career. I built a craft that I *believe* should be stable, but I start bouncing all around the runway long before takeoff. Can someone with a brain take a look and give me a suggestion as to what I've screwed up? Craft file should be all stock, and it represents the best parts I can get at this point in my career. I am also more than willing to accept any advice, pointers, or potatoes--whatever you've got to throw in my direction.

https://onedrive.live.com/redir?resid=FE34D6542466878C!318466&authkey=!ALLoeYpqtnw8UY4&ithint=file%2ccraft

Thanks!

Says it contains locked or invalid parts (should't be locked, as I tried in sandbox mode): RC.radial, RTShortAntenna1, EngineerChip.

If some of that is importand for your plane, try uploading a screenshot.

[tetryds]

1 hour ago, eightiesboi said:

Hey all,

I could really use some input. After watching the YouTube tutorial and reading the wiki, I decided to take a stab at FAR in my new career. I built a craft that I *believe* should be stable, but I start bouncing all around the runway long before takeoff. Can someone with a brain take a look and give me a suggestion as to what I've screwed up? Craft file should be all stock, and it represents the best parts I can get at this point in my career. I am also more than willing to accept any advice, pointers, or potatoes--whatever you've got to throw in my direction.

https://onedrive.live.com/redir?resid=FE34D6542466878C!318466&authkey=!ALLoeYpqtnw8UY4&ithint=file%2ccraft

Thanks!

*Throws potato*

Ok, now let me grab my crystal ball of magicness and figure out what went wrong since I cannot open the craft...

Your landing gears don't seem to be aligned, and that is resulting in uneven forces acting on your craft, making it bounce around and crash.

Select the rotation gizmo by pressing 3, then press F to change to absolute alignment mode, then turn on symmetry, click the wheel and move it, adjusting it so that it's pointing perfectly straight (that is very easy if you follow these steps).

Then, adjust them so that you don't have any angle of attack when taking off, that is the easiest way to prevent issues.

That's all my crystal ball can read, but it tells me there may be something wrong with your stability derivative Mw too, which must be negative, and something tells me your control surfaces are not tweaked for your craft, but that is hard to ensure, I should try telepathy

Jokes aside, pictures also help even though the craft file is provided, this way people can check it out and spot issues also when not on a computer with KSP installed.

[eightiesboi]

14 hours ago, FourGreenFields said:

Says it contains locked or invalid parts (should't be locked, as I tried in sandbox mode): RC.radial, RTShortAntenna1, EngineerChip.

If some of that is importand for your plane, try uploading a screenshot.

Apologies--I am a day-sleeper, so I posted that right before I went to sleep. I meant to post this one, which is only stock parts (No RealChute, KER, or RemoteTech)

https://onedrive.live.com/redir?resid=FE34D6542466878C!324052&authkey=!AKjzM2Vb5MAalk0&ithint=file%2ccraft

 

12 hours ago, tetryds said:

*Throws potato*

Ok, now let me grab my crystal ball of magicness and figure out what went wrong since I cannot open the craft...

Your landing gears don't seem to be aligned, and that is resulting in uneven forces acting on your craft, making it bounce around and crash.

Select the rotation gizmo by pressing 3, then press F to change to absolute alignment mode, then turn on symmetry, click the wheel and move it, adjusting it so that it's pointing perfectly straight (that is very easy if you follow these steps).

Then, adjust them so that you don't have any angle of attack when taking off, that is the easiest way to prevent issues.

That's all my crystal ball can read, but it tells me there may be something wrong with your stability derivative Mw too, which must be negative, and something tells me your control surfaces are not tweaked for your craft, but that is hard to ensure, I should try telepathy

Jokes aside, pictures also help even though the craft file is provided, this way people can check it out and spot issues also when not on a computer with KSP installed.

First, your suggestion about the wheels with the rotation gizmo kept me on the runway until I hit 130 m/s--thank you! I've been playing since .25 but I never knew that trick. This is my first real stab at flying planes instead of rockets.

Second, the screenshots are here:

https://onedrive.live.com/redir?resid=FE34D6542466878C!324056&authkey=!ALK3uHR5boMbD7M&ithint=folder%2c

I noticed that my elevons assigned to roll control activate when I am trying to take off, but deleting them (for the sake of attempting take off) didn't help. I assume my problem is that I'm an idiot and that I have a lot to learn about designing planes before Boeing names me as their chief engineer.

Finally, @tetryds, I tried to read the Elevator control deflection link in your sig, but I keep getting bounced back to the first page of this thread. Can you send me a direct link? And a few more potatoes?

Thanks all... I have some free time today, so I am hoping I can send Jeb skyward.

 

 

Edited June 11, 2016 by eightiesboi
typo

[kcs123]

Don't use fixed landing gears, those are bugged beyond usability in 1.1.2. If you realy insist on those, there is MM patch available that makes those wheels more controlable. That is probably main issue you have encountered.

As for retractable wheels, I found that works better if you set your own friction than left on automatic. For front wheels set friction around 0.5 and for rear wheels set it on 2.0 or more.

Set brakes on wheels to be stronger on ther back wheels and weaker on front. How easy or hard brake force need to be depend on weight of your craft.

[Van Disaster]

Fixed gear are ok, you just need more than you'd imagine: this was my first career plane I think, or at least near to it - certainly the first airframe.

Even something that light needed doubled-up rear gear or it'd just collapse on landing.

@eightiesboi: I can say this without even loading the craft - shape matters under FAR, a lot. Try and keep your designs tidy & blended into a smooth whole, rather than have your wings not really attached to the body properly ( actually having loaded the craft finally, they're not attached at all! ), and the open rear end. Aircraft tend to look smooth with pointy ends for a very good reason doubling up the main gear might solve some takeoff stability problems, but one big thing which solves a lot of those early on is *don't use the runway*. The grass next to it is much smoother.

The craft:

The red derivatives are not good if you don't know what you're doing ( I tend to have red Mw for subsonic speeds for a lot of spaceplanes, but I know how to cope with that ). Simply solved by moving mass forwards relative to the wings. There are gaps everywhere, though? not sure why, did you have tweakscale installed?I'd also think about hanging the engines under the wings so they're not trying to plough the nose into the ground on takeoff. My craft took off on part throttle to cope with that.

Next: your controls are set to -100% for any axis you don't want to use: neutral is the *middle*. The craft could do with more pitch control surface area.

@anyone: can you remember if the orientation of a wing piece matters for actual lift generation? I'm fairly sure it doesn't but I usually keep mine facing mostly the way they came out of the box, so I can't remember.

 

Edited June 11, 2016 by Van Disaster

[FourGreenFields]

8 hours ago, eightiesboi said:

Second, the screenshots are here:

https://onedrive.live.com/redir?resid=FE34D6542466878C!324056&authkey=!ALK3uHR5boMbD7M&ithint=folder%2c

I noticed that my elevons assigned to roll control activate when I am trying to take off, but deleting them (for the sake of attempting take off) didn't help. I assume my problem is that I'm an idiot and that I have a lot to learn about designing planes before Boeing names me as their chief engineer.

Finally, @tetryds, I tried to read the Elevator control deflection link in your sig, but I keep getting bounced back to the first page of this thread. Can you send me a direct link? And a few more potatoes?

Thanks all... I have some free time today, so I am hoping I can send Jeb skyward.

Pretty much what Van Disaster said (only looked at screenshots though). Shape matters way more in FAR.

Build a proper tail, make sure the wings touch the fuselage. Also, considering that you're using those cute little jets (forgot their name), delta wings might be a bad idea - they add alot of drag at subsonic speeds (especially at high AoAs). Build long(ish) relatively thin wings (high aspect ratio) without wing sweep, and as you'll change the tail anyway, you can add a horizontal stabiliser too.

Side note for the screenshots: Even though "CoM in front of CoL" doesn't matter as much as in stock, a screenshot with those two would help (among others to see the position of the CoM relative to the gear).

Going to design a plane with 2 of those jets now. Uploading screenshot soon™.

[Van Disaster]

I cleaned the craft up & adjusted a couple of things like the engine position, built a new install with just FAR and this seems pretty usable - certainly happy on the runway.

Rather lacking in pitch authority but it just took off without eating it's gear. I didn't do anything special to it other than clean up the wings, https://www.dropbox.com/s/xqy4e6d2exndb66/HMSC Fiery Future - Stock Parts VD tune.craft?dl=0 if you want to look at it.

Must thank you - I think I found an issue in my main install that's killing lift for certain combinations of stock wing parts. I don't actually use stock wing parts often but I'm not happy about that ( and if it's affecting me it might well be affecting others ) so I'll chase that a bit.

Edit: something a bit odd going on with this wing - note the lack of lift arrows for the rear panels ( they aren't underneath either.

That was a bare bones install of FAR + Pilot Assistant rather than my full install.

Edited June 11, 2016 by Van Disaster

[FourGreenFields]

Ok, built it. Had to mess with the settings for the gears to make her stay on course, but she takes off, flies, and lands fine.

 

Takeoff, and landing speed about 45-55m/s with the main fuel tank half empty. Reached 150m/s on about 1/3 throttle. Takes off by itself if you extend the flaps.

 

EDIT: May need to upload somewhere else to make the screenshots show here... or I don't have a clue atm.

EDIT2: Ok, uploaded it on imgur.

Edited June 11, 2016 by FourGreenFields

[Van Disaster]

I rebuilt the wing out of fresh parts, this looks healthier:

Note I used empty size0 tanks as engine pods this time. @eightiesboihow/where did you attach your engines?

[eightiesboi]

All,

Thank you for all the input. I have a lot to work on now! I *did* figure out that I had my control surfaces set incorrectly (which explains why my elevons designated for roll control would angle opposite of my pitch elevons whenever I tried to takeoff!). Built a second craft with long, thin wings that flies relatively well, although landing so far is, erm, difficult. I also notice that it is plastered to the ground and I have to run out of runway to get airborne, but then I pitch up easily. I suspect that my front landing gear may be too low, keeping my nose to close to the ground.

@kcs123 - I don't have access to retractable wheels yet, as I just started the tech tree (ETT, this time) in my career. But your points are good ones--I'd been using auto friction up until now. Thanks!

@Van Disaster - Wow! Thank you! I'll be tearing apart the revised craft file to see what you did! To answer the questions you asked, no, I did not use tweakscale (don't have it installed, actually), and my parts were placed using only the stock offset tools, which is probably why you see those gaps. I have since added editor extensions to this install (used to use it, thought I wouldn't need it post 1.1). The engines were connected directly to the air intakes and surface attached to the fuel fuselage (which surprisingly worked). My runway is fully upgraded (I thought the potholes were a problem before tetryds suggested I reorient my landing gear).

@FourGreenFields - Could I convince you to link the .craft file for me? I'd love to take that apart as well.

Lastly (to anyone), are there any suggestions on how to determine proper gear placement AND height? I saw in the FAR YouTube tutorial that a slightly nose down arrangement, while making it more difficult to take off, also makes it easier to stick the landings. But I think that's one of the reasons I have difficultly in taking off. Is there a happy medium?

Again, thank you all--I very much appreciate the help you've given me.

 

Edited June 11, 2016 by eightiesboi

[kcs123]

10 minutes ago, eightiesboi said:

Lastly (to anyone), are there any suggestions on how to determine proper gear placement AND height? I saw in the FAR YouTube tutorial that a slightly nose down arrangement, while making it more difficult to take off, also makes it easier to stick the landings. But I think that's one of the reasons I have difficultly in taking off. Is there a happy medium?

Hard to say what "proper" way is. Depend a lot of each craft design. Somehow, design with nose slightly tilted down 1-3 degree suited me well. Slope when front wheel just touching ground and rear wheels (just wheel, not leg) is half sinked into ground, or barely visible above ground served me well in various designs.

Taking off should not be more difficult than on other design type. Try to place rear landing gears just behind COM, so your elevators will have decent leverage force to tilt up craft. Just page or two back, I described how to use it in combination with flaps.

On well designed craft, when I'm in mood to fine tweak them, craft will be firmly on runway until you reach enough speed for take off. Once you reach critical take off speed, elevators also have enough pitching force to change AoA and aircraft can fly. Oposite works well too. In landing aproach, if aircraft speed is close as takeoff speed, soon as craft touch ground, craft should be "sticked" to ground because elevators don't have enough leverage force to tilt nose up again.

[FourGreenFields]

8 hours ago, eightiesboi said:

@FourGreenFields - Could I convince you to link the .craft file for me? I'd love to take that apart as well.

Lastly (to anyone), are there any suggestions on how to determine proper gear placement AND height? I saw in the FAR YouTube tutorial that a slightly nose down arrangement, while making it more difficult to take off, also makes it easier to stick the landings. But I think that's one of the reasons I have difficultly in taking off. Is there a happy medium?

Again, thank you all--I very much appreciate the help you've given me.

 

https://www.dropbox.com/s/ra2vyxmx67quhci/P1.craft?dl=0

Brakes are still kind of weak, and she likes to steer off course when you brake, but that can be controlled (or just use the landing chute). As said landing and takeoff at about 50m/s, may want to land at slightly higher speed to avoid tail strikes. Lower flaps on action group 1, raise flaps on action group 2. With deployed flaps and full elevator she may stall, so a JS is recommended unless you tweak the controls a little.

 

Assuming a nose-gear setup, the main gear should be placed slightly behind CoM. How "slightly" depends (i.e. the AoA during touch down (too close to CoM and the wheels will be in front of the CoM at high AoA, causing tail strikes when touching down hard), and elevator authority). If you set it up so you can pull the nose up with the elevator (or for more crazy designs with elevator + RCS/flaps/a chute/black magic), it doesn't matter much whether the nose points down or up.

TLDR: The sweetspot(s) for gear placement depend on the plane.

Edited June 11, 2016 by FourGreenFields

[eightiesboi]

@kcs123 and @FourGreenFields, thank you. Just got back from a late night run through the park and booted up KSP. Going to try to put into use what all of you taught me in the last 24 before I crash for the night... or day.

My Kerbals see more sun than I do.

Edited June 11, 2016 by eightiesboi

[VeryDarkSkin]

Hey, I am new here and I only play on FAR with 64k in hard career and some realism mods, because I am masochist like that ;P...and here is a pic of my first twin prop. I use hard career because I want money constraints and purpose for craft. I really want bd armory contracts, but cant find any for 1.1.2.

 

I am about 1/4th way through the tech tree.

Space planes are only a distant dream for me hehe. 

Edited June 12, 2016 by VeryDarkSkin

[Van Disaster]

BDArmory is not 1.1.2 compliant, so i'd not worry about that. Surface science mod might be worth a look, that's somewhat realistic

As for spaceplanes, 64k makes that extremely awkward. I posted some early tech tree spaceplanes on the previous page, but currently I'm running stock solar system... I guess a bigger lifting craft would mean a bigger boost stage so it's possible one of the little carrier/booster/spaceplane combos might work. The only problem with that is the carrier I built was at the limit of the first SPH upgrade already. You could try vertical launch perhaps, that's how I got my first ones up.

Still, 64k and the size limits of early building upgrades, not sure that's going to really work.

These were two really handy craft from early tech tree for my last game:

I am using KAX props, with Sounding rockets and one of the DMagic science mods for a few little generic sci experiments, so biome hopping was pretty profitable.

Edited June 12, 2016 by Van Disaster

[He_162]

In normal KSP I find it very hard to replicate specifics in aircraft, just general out-takes on them, and I'll tell you what I mean here in a minute.

 

With FAR, you can make much more diverse changes by doing very little changes to an aircraft.

If you try to replicate any of these three aircraft, you will find they all fly generally the same in normal KSP, but entirely different in real life:

MiG-15

Yak-30

La-15

 

Now with FAR, you can do these things.

 

Just my thoughts on how cool FAR is, and some concepts for you guys to think about

[Van Disaster]

@He_162: did you ever enter a BDA dogfight contest? I'm not sure there's any FAR-based ones running at the moment ( well BDA is not currently under active development either ), but you *definitely* notice small differences in aircraft design then.

Edit: actually I have an example of family tree development from a BDA contest: prototype here,

Spoiler

 

and much later development of the same airframe from the same contest:

Spoiler

 

 

Edited June 12, 2016 by Van Disaster

[He_162]

5 minutes ago, Van Disaster said:

@He_162: did you ever enter a BDA dogfight contest? I'm not sure there's any FAR-based ones running at the moment ( well BDA is not currently under active development either ), but you *definitely* notice small differences in aircraft design then.

Oh trust me, you may notice them, but they are no where near as defined as real life, but much more noticeable with FAR.

If I move the wings on the La-15 up by 1 degree of dihedral, it becomes unstable in real life.

If I moved the wings of the Yak-30 1/2 foot forward, it becomes highly unstable in real life.

If I do either in KSP, neither aircraft seem to have been effected in the slightest.

 

Oh, and no I havn't, should I?

Edited June 12, 2016 by He_162

[Van Disaster]

4 minutes ago, He_162 said:

Oh, and no I havn't, should I?

If you enjoy detailed aircraft design it's worth it. The AI is immensely frustrating, but you do get results from putting effort into tweaking your craft. However you'll have to wait for Baha to come back from his dev sabbatical or someone to fork BDA & fix some things, I think.