Official FAR Craft Repository

[FirroSeranel]

My new favorite design type. Mach 3.05, 16% throttle on two turbojets, 12km altitude cruising speed. It'll hit mach 4 just above sea level... also just before it explodes from overheating. XD Mostly stock parts, but the cockpit is OPT's Mk2 cockpit, and the landing gear is from Adjustable Landing Gear. I call her Hook... because my first time designing one like this, I called it Kraken and bad, -bad- things happened to my KSP install. <.<

Oh and she's stable with Pilot Assistant at 4x timewarp, so nice, quick, easy survey runs on Kerbin.

Edited May 31, 2015 by FirroSeranel

[Kitspace]

Hello.

I have noticed one thing happening quite often.

When a wing part is placed onto an approximately right spot on an airplane for the first time the sweep shows a certain stability graph and a certain stalling point. Then I move the wing to a position that looks more optimally in response to those graphs by picking it up and attaching again. The strange thing is that after the second attachment the stalling point is significantly less and it is quite impossible to get it back even by putting the wing back where it was.

What is wrong and why is it happening?

Thank you!

[kcs123]

Hello.

I have noticed one thing happening quite often.

When a wing part is placed onto an approximately right spot on an airplane for the first time the sweep shows a certain stability graph and a certain stalling point. Then I move the wing to a position that looks more optimally in response to those graphs by picking it up and attaching again. The strange thing is that after the second attachment the stalling point is significantly less and it is quite impossible to get it back even by putting the wing back where it was.

What is wrong and why is it happening?

Thank you!

I recommend using offset gizmo, once wings are in close proximity where you want them to be.

[Hodo]

My new favorite design type. Mach 3.05, 16% throttle on two turbojets, 12km altitude cruising speed. It'll hit mach 4 just above sea level... also just before it explodes from overheating. XD Mostly stock parts, but the cockpit is OPT's Mk2 cockpit, and the landing gear is from Adjustable Landing Gear. I call her Hook... because my first time designing one like this, I called it Kraken and bad, -bad- things happened to my KSP install. <.<

Oh and she's stable with Pilot Assistant at 4x timewarp, so nice, quick, easy survey runs on Kerbin.

http://i57.tinypic.com/2u9igb5.jpg

Can I get the link to that cockpit?

[Littlerift]

My new favorite design type. Mach 3.05, 16% throttle on two turbojets, 12km altitude cruising speed. It'll hit mach 4 just above sea level... also just before it explodes from overheating. XD Mostly stock parts, but the cockpit is OPT's Mk2 cockpit, and the landing gear is from Adjustable Landing Gear. I call her Hook... because my first time designing one like this, I called it Kraken and bad, -bad- things happened to my KSP install. <.<

Oh and she's stable with Pilot Assistant at 4x timewarp, so nice, quick, easy survey runs on Kerbin.

http://i57.tinypic.com/2u9igb5.jpg

A very sleek aircraft. I love how unconventional it looks while still looking functional.

Can I get the link to that cockpit?

http://forum.kerbalspaceprogram.com/threads/97525-1-0-2-WIP-OPT-Space-Plane-v1-6-9

[Kitspace]

But still why do the calculations become inadequate?

Or do they become more adequate than first time?

[SuicidalInsanity]

A WIP engine test that serves as another example of the power of gimbal. I call this one 'Thrust-Vectoring covers a multitude of sins'.

When designing FAR compatible airframes, its amazing what delta wings will let you get away with.

[Guest]

Anyone knows if the aeroviz feature is planned to come back?

[Wanderfound]

I've got a new toy for the racetrack:

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Craft file at https://www.dropbox.com/s/fx3q0f3vhw70wbt/Zoomie.craft?dl=0

(all stock parts, Kerbpaint paintjob optional, designed for use with Dynamic Deflection)

I use it on these racetracks:

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How do I make it faster?

The problem isn't raw speed; even a single turbojet plane can rapidly accelerate to cockpit-melting speed at 200m. The problem is getting around the track more quickly.

Acceleration helps, but we've already got ample power and a fairly slick airframe (wave drag of 0.57 from a 3.8 cross section on the twin-engine ship). It's mostly about cornering; how do I get the tightest, fastest turns? The single-engine one can safely hold the g-meter pegged at anything up to Mach 2; the twin-engine delta is tending to peak at 10g or so, but I can probably increase that by upping the deflection on the canards a bit. Even with the g-meter pegged, the corners on the track tend to hold me to a little above Mach 1 if I don't want to run wide, with bursts of Mach 2-3 at the ends of the straights.

What else? I'm open to all suggestions, no matter how left-field. Airbrake-driven handbrake turns have been tried, but tend to lead to rapid explosive disassembly when deployed at Mach 2 in thick air. I'm open to rocketry, but keep in mind that ships will reliably overheat shortly after hitting Mach 3 at this altitude (the gates must be passed below 200m).

Edited June 2, 2015 by Wanderfound

[Traches]

How do I make it faster?

Have you trimmed as much mass as possible? Carry just barely enough fuel to complete the course, make sure you've dumped your monopropellant from the cockpit, mess with wing strength sliders and get them as low as possible without breaking, and remove everything that's not absolutely necessary.

Airbrakes could work; you need to set them not to deflect very far. Try to place them in such a way that they don't cause a pitching motion when they deploy.

You only gave us about 40 shots of its butt, maybe one or two from the side & front?

[kcs123]

Here is some rocket example, just enough to put probe in Kerbal and/or Mun orbit. This one is from SETIctt early career, to help you gat started, not to be ultimate problem solver.

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And another wierd design that works well with FAR. Career put some more challange to spaceplane design. You need to keep part count/weight at low level and width lenght and height of plane as well to fit level one or two max of SPH and runway. Another limitation is parts available to build such craft and money in budget.

I have first created something for those high altitude measurments contracts.

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And here is example how this design elvolved to space plane. It can achieve LKO even without boosters, but those provide extra 300 m/s of dV, so it is not all that bad and those boosters are pretty cheap.

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[Svm420]

Low wave drag on a normally designed plane.

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Anybody beat this ratio of wave drag to cross section area on a plane?

[gilflo]

Hello

Here is my 4 RAPIER Spaceplane tested with FAR.

Flies perfectly

Re-entry and landing

Find it here

http://kerbalx.com/gilflo/FAR-Avenger-3

[Wanderfound]

Have you trimmed as much mass as possible? Carry just barely enough fuel to complete the course, make sure you've dumped your monopropellant from the cockpit, mess with wing strength sliders and get them as low as possible without breaking, and remove everything that's not absolutely necessary.

Airbrakes could work; you need to set them not to deflect very far. Try to place them in such a way that they don't cause a pitching motion when they deploy.

You only gave us about 40 shots of its butt, maybe one or two from the side & front?

Sorry about the buttshots; it's hard to manage 15g at 100m in anything other than chase view.

Here's the single-engine raceplane (craft file at https://www.dropbox.com/s/r4jdh62ipy9czdk/Kerboracer.craft?dl=0):

And this is the twin-engine version (craft file at https://www.dropbox.com/s/fx3q0f3vhw70wbt/Zoomie.craft?dl=0):

At the moment, the single-engine ship is the faster of the two on the track; it turns a little tighter, and has enough punch to hit Mach 3 at the end of the long straights (and more speed is useless, as it'll explode from overheating at around Mach 3.1...). The twin-engine version probably has more potential, but it requires more care to fly; it's easy to overshoot a turn.

- - - Updated - - -

Another rocketry example: gimbal is king.

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Craft file at https://www.dropbox.com/s/fmis3ep4bu48uu8/Krokoduck.craft?dl=0

Edited June 3, 2015 by Wanderfound

[Wanderfound]

Revised version of the single engine ship; will happily and stably hold 15g all day long.

The twin engine beastie doesn't handle perfectly at low speed (over-controlled, tends to pitch wobble) but is almost as good as the single-engine one in supersonic turns. With both, the main problem is in running wide (as much a matter of piloting judgement as anything else, but reducing wing loading should also help) and exploding through speed-induced overheating (about Mach 3 for both). No idea of how to improve the latter, though.

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Craft file at https://www.dropbox.com/s/us7yewbdp5y7nmd/Kerboracer%20MG.craft?dl=0

Edited June 3, 2015 by Wanderfound

[FourGreenFields]

Low wave drag on a normally designed plane. http://imgur.com/a/6koX4 Anybody beat this ratio of wave drag to cross section area on a plane?

http://kerbalx.com/FourGreenFields/P6-Arrow

Ratio of 15 and higher (changes randomly each calculation it seems). On strict area ruling.

I think it was 25 or something when I calculated on default settings.

I marked it as spaceplane on kerbalX 'cause it can zoom climb to space, and live. However, it is a record plane, and not realy all that usefull imo.

Anyway...

She's alive, ALIVE! MUHAHAHAHAHA*coughcoughcough*

*clears throat*

http://images.akamai.steamusercontent.com/ugc/26240387382683965/D5A98353F9CDFCA2FFFD458C89F7666A6EFA6A0E/

The Heinkel "Lerche" ("Lark") replica (if you can call it a replica if it is modelled after a "paper plane").

http://images.akamai.steamusercontent.com/ugc/26240387382683525/ED9206CA3CA75C4AD431B4E326AA1E031AA5324E/

German late war projects ftw! You can get anything from area-ruled transsonic designs (which are super-/hypersonic with the engines we have here), to all kinds of crazy stuff, to all kinds of not-just-as-crazy stuff, to normal prop planes just replicating their designs.

[jrandom]

Design question: In the below craft, above Mach 1 I get a red derivative in Fwd Vel Zu saying "Change in Z-direction acceleration with respect to X-direction velocity; should be negative". I've been sliding wing parts around but haven't found any correlation that makes the number go in the right direction, and I'm not even quite sure what it means. The number goes green at higher altitudes, but I'm wondering what this particular derivative actually indicates behaviour-wise.

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[FourGreenFields]

Design question: In the below craft, above Mach 1 I get a red derivative in Fwd Vel Zu saying "Change in Z-direction acceleration with respect to X-direction velocity; should be negative". I've been sliding wing parts around but haven't found any correlation that makes the number go in the right direction, and I'm not even quite sure what it means. The number goes green at higher altitudes, but I'm wondering what this particular derivative actually indicates behaviour-wise.

Well, considering we are talking about a yawing movement here, my guess is that it should get better with a higher yaw stability (bigger tail fin, more wing sweep, etc.). Not realy sure about that one though, never had that problem.

[jrandom]

Hrm... because X direction is forward and Z direction is down. Where does yaw come into that?

[FourGreenFields]

Hrm... because X direction is forward and Z direction is down. Where does yaw come into that?

Oh, wait. Thought "Z-angular acceleration", sorry. Then I have absolutely no idea. Just try to fly at the speed and alt it is red.

EDIT: Or well, actually... any chance you are producing negative lift at 0 AoA? Maybe try re-calculating with flaps down, or use shift + qweasd to rotate the root part for the calculation.

Edited June 4, 2015 by FourGreenFields

[jrandom]

Oh, wait. Thought "Z-angular acceleration", sorry. Then I have absolutely no idea. Just try to fly at the speed and alt it is red.

EDIT: Or well, actually... any chance you are producing negative lift at 0 AoA? Maybe try re-calculating with flaps down, or use shift + qweasd to rotate the root part for the calculation.

Oh hey, that might be it. Never even occurred to me to rotate the root part to get different AoA for the derivatives!

[Wanderfound]

FAR rocketry at the smaller end of the scale:

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Craft file at https://www.dropbox.com/s/bki39ohbj7vr40i/Kerbodyne%20Jetlift.craft?dl=0

[FourGreenFields]

And another WWII replica. The Messerschmitt P.1110 transsonic fighter. None were built. Didn't model it after the picture on the wikipedia article, but after a blueprint from a book. Looked alot like this.

Link: http://kerbalx.com/crafts/2910

http://imgur.com/a/V9aDv

Also, I've uploaded my "Lerche"

Edited June 6, 2015 by FourGreenFields
added imgur album-link. No idea how to add an album the normal way :/

[Virtual Flyboy]

Design question: In the below craft, above Mach 1 I get a red derivative in Fwd Vel Zu saying "Change in Z-direction acceleration with respect to X-direction velocity; should be negative". I've been sliding wing parts around but haven't found any correlation that makes the number go in the right direction, and I'm not even quite sure what it means. The number goes green at higher altitudes, but I'm wondering what this particular derivative actually indicates behaviour-wise.

http://imgur.com/a/i73sB

That actually sounds a bit like inertia coupling. I don't know if FAR even takes that into account.

Probably not though, you have decent sized wings and your COM is pretty far up, but in any case the first thing I would try is to increase your vertical tail area. When one axis is overriding another, it's usually a good sign there is an imbalance of control between them.

Edited June 8, 2015 by Virtual Flyboy

[gilflo]

Hi guys, I got a question about spaceplane engine choice

I am wondering if 4 RAPIER are the best choice for 70-80T spaceplane under FAR.

Here is mine: http://kerbalx.com/gilflo/FAR-Avenger-3

I am trying to find a combination giving the best DV option with enough TWR for orbit.

I need 4 turbo to be able to take off from runway, so 4 turbojets + another combination of Closed cycle engine will add more weight and I need more than 0.5 TWR to make orbit from 20.000m where turbojets become inefficient.

A combination of 2 turbo, 2 rapier and 2 nuclear or 2 other engines.... i am not sure that the weight added gives me more DV on final.

Then once in vacuum if you want to transit on Mun you can light 2 or 4 engines, you don't get more DV, you just do it faster or lower.....