Official FAR Craft Repository

[Littlerift]

Hello all. I had an account on this forum a long time ago, but as I've lost that email address and can't access the account (and because KSP is finally released ) I decided that a fresh start might be good.

This is what I've been working on for a few days. It's inspired really by attempts I had in 0.90 to use B9 Procedural Wings to create a weapon's bay for fighters. However, due to the way oldFAR worked this was fairly impractical. However, with the new voxel method you don't get wings stalling just because another wing leads onto them in a panel-like way.

Anyway...

She performs surprisingly well, given that before embarking on this project my more conventional aircraft were rather uninspiring. At transonic speeds at sea level she'll turn while quite tightly, topping out the Gs and maintaining speed. At altitude she'll reach Mach 4 with only little nose dipping. So I suppose she's a kind of interceptor?...

I wanted to go with a sealed canopy design, partly because happing a bubble canopy sticking out of the top would ruin the appearance, and also because sealed canopies are cool. This led to a few issues with the earlier designs, where I made the roof of the canopy out of flaps whose spoilers would be activated to open it up. This design, though, made it incredibly difficult to get the Kerbal out of the cockpit, and meant that I had to have a series of ladders, which, again, ruining the aesthetics. So instead, I decided to have the seat descend out of the bottom of the frontal fuselage, which led to a rather sci-fi design that's sure to wow the public at airshows.

Her cross-section curves are a little wavy, but I can't think of any ways to improve it particularly without disrupting how she looks. Overall I'm very happy with the initial prototype, and now I'm just working on tweaking things to maximise its potential. I really need to say that FAR is the main thing that keeps me coming back for more KSP. I was more excited for the release of nuFAR than I was for KSP 1.0. The new voxel method is fantastic and very intuitive, and it's certainly opened up whole new possibilities. Now that I know that this construction method works I've got loads of ideas that I want to test out, and I just wanted to float the method with you guys and girls to see if any of you have done anything similar.

Thanks.

[Traches]

Posting my SSTO spacetruck. If you can fit it into 2 mk3 cargo holds, it can take it to orbit. Important mods used are tweakscale, procedural parts (for the nose), and adjustable landing gear.

Album:

http://imgur.com/a/oyga9

[eddiew]

Posting my SSTO spacetruck. If you can fit it into 2 mk3 cargo holds, it can take it to orbit. Important mods used are tweakscale, procedural parts (for the nose), and adjustable landing gear.

It's a beautifully smooth creation for such a big plane How 'legit' is tweakscale with engines? Taking it from 1.25 to 2.5m I'd expect 8x the weight, thrust, and fuel drain.

[taniwha]

eddiew: doubling the scale only quadruples the thrust (mass is cubed, thrust is squared (governed by the area of the nozzle)).

[eddiew]

eddiew: doubling the scale only quadruples the thrust (mass is cubed, thrust is squared (governed by the area of the nozzle)).

That's a fair point Is that what tweakscale actually does though, or do we end up with a crazy powerful engine that's too good for what it weighs? (I'll check when I get home, but that's many hours away )

[FourGreenFields]

That's a fair point Is that what tweakscale actually does though, or do we end up with a crazy powerful engine that's too good for what it weighs? (I'll check when I get home, but that's many hours away )

Well, if that's how tweakscale works, then using 4 original-size engines should be better. Why? Because they also give 4 times the thrust, but at four times the weight, instead of 8 times the weight.

Anyway: The new KAX update ruined all my high-alt prop planes. Or actually all prop planes. They can fly at low-alt allright, but I don't think any of them are able to reach any alt close to what they were able to reach in RL. Which is a joke considering that that is supposed to tech used alongside rockets...

Anyone know how to supercharge them or something? Simple air-intakes and engine pre-coolers dont work.

Edited May 19, 2015 by FourGreenFields

[Gfurst]

Anyway: The new KAX update ruined all my high-alt prop planes. Or actually all prop planes. They can fly at low-alt allright, but I don't think any of them are able to reach any alt close to what they were able to reach in RL. Which is a joke considering that that is supposed to tech used alongside rockets...

Anyone know how to supercharge them or something? Simple air-intakes and engine pre-coolers dont work.

Sorry but I'm partially responsible for the prop engines, and they still need a bit of work... But what kind of prop planes reach high altitude in real life?

[kcs123]

Just testing those prop engines from latest KAX, seems OK to me, but I didn't have time for extensive tests. Those are nice touch for overall career progresion along with SETIctt mod.

Creating smal props planes early in career is nice distraction from those heavy SSTOs that i used to build

While playing witn new FAR, most of us clip some parts inside fuel tanks etc. It is kind of cheating, but needed to maximize subsonic to supersonic speed efficieny.

To counterpart this, I was thinking about small plugin that will check if some part is cliped inside fuel tank or wet wing mesh, for example.

Plugin should calculate volume of cliped part and reduce fuel resources from bigger mesh by percentage(%) how much volume is used by cliped in parts, compared to overall mesh volume.

Don't know if such thing is possible to make, considering KSP game engine limits and ability to detect parts cliping at all. But it will be nice touch if something like that can be done.

[Wanderfound]

I just took the KAX props for a spin. I did the obvious thing, built a pseudo-Spitfire with one of the high power prop engines on the nose.

Fun, but: supersonic within seconds of leaving the runway. The power or speed curves might need a bit of a nerf. Or make the "bomber" engine larger and add a medium-power engine for small fast (but subsonic) prop planes.

Edited May 19, 2015 by Wanderfound

[FourGreenFields]

Sorry but I'm partially responsible for the prop engines, and they still need a bit of work... But what kind of prop planes reach high altitude in real life?

Well, some prop planes from WWII I have data on (modern planes built for high-alt will prob manage to fly even higher):

Focke-Wulf Ta 152 H-1 (Late war german high alt fighter) service ceiling 14.8km (with GM 1, which increased engine performance at high alts)

Focke-Wulf Fw 189 A-2 (german mid war short-range reconnaissance plane) 7.3km, 2.4km if one engine dies

Focke-Wulf Fw 190 A-8 (mid-ish war fighter) sevice ceiling 10.3km, with GM 1 11.4km

Focke-Wulf Fw 200 C-3/U4 (4 engined bomber, based on pre-war civilian plane) service ceiling 5.8km

Messerschmitt Me 110 G-4c/R3 (heavy fighter, I think later variant, but based on pre-war design) service ceiling 8km.

Messerschmit Me 109 G-6 (mid-ish war fighter) service ceiling 11.55km

Heinkel He 219 A-7/R2 (late war night fighter) service ceiling 9.8km

Heinkel He 111 H-16 (german bomber, variant from mid war) service ceiling 6.7km (full bombload (= roughly 2.5 tons), full fuel-load) to 8.5km (no bombs, fuel tanks half filled)

Junkers Ju 52/3m g7e (german transport plane, designed pre-war) service ceiling 5.9km.

Junkers Ju 87 D-1 (dive bomber) service ceiling 7285m at 5842 kg, 4730m at 6600kg, empty weight with equipment is 3900kg.

Junkers Ju 88 G-7b (heavy fighter, based on the Ju 88 bomber/dive bomber) service ceiling doesnt get mentioned but a top speed at an alt of 10.2km is mentioned.

Dornier Do 335 A-0 (fighter/heavy fighter - twin engine, one engine in the nose, one engine in the tail. Late war), service ceiling at 9.5 tons weight (empty weight without equipment was 6530kg) 9.5km, with one engine 6.8km.

Dornier Do 217 M-1 (bomber, late war) service ceiling 7.35km at max bombload, 9.5km without bombes.

Heinkel He 177 A-5 (4 engined heavy bomber, and "dive bomber" (which is a bit of a joke)) service ceiling 6.8km at 31 tons (empty weight 16.8 tons)

Source is the german translation of "Wings of the Luftwaffe", Eric Brown.

Lowest service ceiling here is 5.8km.

On the other hand, up to nearly 15km for an high-alt fighter - and that isn't using the in-game turbo-props, but a supercharged in-line engine. I expect turbo-props to have better perfomance up high.

Now sadly I don't have any data on how speed and alt affect engine performance, but compared to the pretty sharp limit at 7km most of those birds were able to fly "pretty high". Which is prob due to superchargers.

The effect of superchargers can be seen pretty clearly here:

http://www.ww2aircraft.net/forum/attachments/aviation/62235d1299781604t-combat-altitude-eto-51_vs_fw_190_speed.png

Those graphs are of 2 190s, and 2 P-51s. You can clearly see where the supercharger gears in the P-51s get activated.

If I am not mistaken the 190 Ds there used turbochargers, which don't have gears - you can still see where they fail to provide enough compressed ait for the engine.

Basicly, I don't realy ask for a normal "buff". However, I'd like some way to increase high-alt performance at the cost of low-alt performance.

The simpler method would be to decrease air intake/increase air consumption of prop engines of all kinds, while massively increasing that artificial max-alt cap. That way your engine would be able to run at high alts if you provide the air, which comes at the cost of higher weight and drag. Advantage is that it is pretty intuitive (moar powar!), and uses readily available parts.

Or right click menu added option of customising the supercharger (number of gears, and "strength" or whatever it's called of the gears). Wouldn't be quite as easy to understand for someone who doesn't know what he is doing, but slightly more realistic. Should definitly add weight. Not sure about wether it would also reduce engine power down low.

o7 Anyway, still like KAX.

Edited May 19, 2015 by FourGreenFields
wall of text, highlighted the service ceilings

[tetryds]

Yeah but remember that Kerbin's atmosphere is not the same as Earths.

And that this topic would be better discussed at the KAX thread.

If you want to discuss design stuff and the applications of the engines, go for it, but this is not the place to discuss balancing the mod.

For a more accurate performance just wait for AJE.

[Nerd1000]

Well, some prop planes from WWII I have data on (modern planes built for high-alt will prob manage to fly even higher):

Focke-Wulf Ta 152 H-1 (Late war german high alt fighter) service ceiling 14.8km (with GM 1, which increased engine performance at high alts)

Focke-Wulf Fw 189 A-2 (german mid war short-range reconnaissance plane) 7.3km, 2.4km if one engine dies

Focke-Wulf Fw 190 A-8 (mid-ish war fighter) sevice ceiling 10.3km, with GM 1 11.4km

Focke-Wulf Fw 200 C-3/U4 (4 engined bomber, based on pre-war civilian plane) service ceiling 5.8km

Messerschmitt Me 110 G-4c/R3 (heavy fighter, I think later variant, but based on pre-war design) service ceiling 8km.

Messerschmit Me 109 G-6 (mid-ish war fighter) service ceiling 11.55km

Heinkel He 219 A-7/R2 (late war night fighter) service ceiling 9.8km

Heinkel He 111 H-16 (german bomber, variant from mid war) service ceiling 6.7km (full bombload (= roughly 2.5 tons), full fuel-load) to 8.5km (no bombs, fuel tanks half filled)

Junkers Ju 52/3m g7e (german transport plane, designed pre-war) service ceiling 5.9km.

Junkers Ju 87 D-1 (dive bomber) service ceiling 7285m at 5842 kg, 4730m at 6600kg, empty weight with equipment is 3900kg.

Junkers Ju 88 G-7b (heavy fighter, based on the Ju 88 bomber/dive bomber) service ceiling doesnt get mentioned but a top speed at an alt of 10.2km is mentioned.

Dornier Do 335 A-0 (fighter/heavy fighter - twin engine, one engine in the nose, one engine in the tail. Late war), service ceiling at 9.5 tons weight (empty weight without equipment was 6530kg) 9.5km, with one engine 6.8km.

Dornier Do 217 M-1 (bomber, late war) service ceiling 7.35km at max bombload, 9.5km without bombes.

Heinkel He 177 A-5 (4 engined heavy bomber, and "dive bomber" (which is a bit of a joke)) service ceiling 6.8km at 31 tons (empty weight 16.8 tons)

Source is the german translation of "Wings of the Luftwaffe", Eric Brown.

Lowest service ceiling here is 5.8km.

On the other hand, up to nearly 15km for an high-alt fighter - and that isn't using the in-game turbo-props, but a supercharged in-line engine. I expect turbo-props to have better perfomance up high.

Now sadly I don't have any data on how speed and alt affect engine performance, but compared to the pretty sharp limit at 7km most of those birds were able to fly "pretty high". Which is prob due to superchargers.

The effect of superchargers can be seen pretty clearly here:

http://www.ww2aircraft.net/forum/attachments/aviation/62235d1299781604t-combat-altitude-eto-51_vs_fw_190_speed.png

Those graphs are of 2 190s, and 2 P-51s. You can clearly see where the supercharger gears in the P-51s get activated.

If I am not mistaken the 190 Ds there used turbochargers, which don't have gears - you can still see where they fail to provide enough compressed ait for the engine.

Basicly, I don't realy ask for a normal "buff". However, I'd like some way to increase high-alt performance at the cost of low-alt performance.

The simpler method would be to decrease air intake/increase air consumption of prop engines of all kinds, while massively increasing that artificial max-alt cap. That way your engine would be able to run at high alts if you provide the air, which comes at the cost of higher weight and drag. Advantage is that it is pretty intuitive (moar powar!), and uses readily available parts.

Or right click menu added option of customising the supercharger (number of gears, and "strength" or whatever it's called of the gears). Wouldn't be quite as easy to understand for someone who doesn't know what he is doing, but slightly more realistic. Should definitly add weight. Not sure about wether it would also reduce engine power down low.

o7 Anyway, still like KAX.

The Fw190 D series used a geared supercharger just like the P-51s. Look at the line for the D-9: It has one of those 'sawtooth' steps like the Mustangs do, but less drastic. The D-12 was a prototype, so I'm no exactly sure of the details, but think that it had a 3-speed supercharger rather than the 2-speed design used on the D-9 and the Mustang. As a result there are 2 smaller drops in speed as you climb rather than 1 big one.

I'm inclined to add another 'high altitude' plane to your list- the Westland Welkin, with a service ceiling of 13 km. Service ceiling FYI is a measure of rate of climb at altitude- it is usually defined as the altitude where the aircraft's best rate of climb is 1 m/s. The Ta-152H is a special case because the GM-1 system is a nitrous oxide injection system- the engine can operate at much higher altitudes because it is carrying a proportion of its oxidizer in the plane.

Subsonic, straight winged piston props had a very narrow flight envelope at high altitudes- The Welkin's stall speed at 13 km was only just below its critical mach number, so increasing speed would lead to a shockwave induced stall and decreasing speed would lead to a normal angle of attack induced stall.

As far as modelling the props is concerned, we really need a separate module with a power curve for the engine at different altitudes and a propeller curve that models how effectively the propeller converts that power into thrust at different speeds.

Supercharged piston engines in general will have a 'sawtooth' power curve (as seen in your speed chart) due to gear shifts, turbocharged piston engines will produce the same amount of power all the way up to their full throttle altitude and then steadily lose power, and turboprops will produce max power at sea level and steadily less power as altitude increases.

[Wanderfound]

Large-payload finless FAR rocketry still very much doable:

Javascript is disabled. View full album

[Gfurst]

Large-payload finless FAR rocketry still very much doable:

Very cool, specially the hidden lander, any hints?

[Wanderfound]

Very cool, specially the hidden lander, any hints?

Anything in particular?

Build the lander-in-cargo-bay first. With the lander, concentrate as much mass as possible down low. As well as aiding balance during landing, it also keeps it aerodynamically stable flying engine-first while aerobraking. The engines serve as heat shields, and everything else is tucked away safely. The airbrakes help with keeping it online, too; they're set as control surfaces as well as drag brakes.

To fit in the bay, it will need to be skinny. Vertically-flipped radial tanks are useful, as are Oskar B's. Chunky legs help compensate for a narrow footprint.

The ability of scientists to reset goo and sci jr's means that you don't need more than one. The lander instruments mean that the mothership can do without an integral science suite, too (although you might want one for simultaneous operations).

The mothership is basically just a large LF fuselage and a large cargo bay with four nukes strapped on back. The bits of oxidiser in the assorted adaptors act as fuel reserve for the lander. The boosters are a quartet of streamlined asparagused Mammoths.

Edited May 21, 2015 by Wanderfound

[Gfurst]

Anything in particular?

Thanks, but I actually meant about the stability in launch without fins and such. Technically, all we need is to have the natural CoP lower than the CoM, and maybe starting off with a lower TWR?

[Bedwyr]

That is gorgeous and well designed Wanderfound. Well done.

[luckyhendrix]

Hello, does anyone have a SSTO mk2 size plane that can reenter without burning up ?? my craft here cannot reenter anyway I try ... I've tried very shallow reentries and more aggressive, but even with the very shallow one my carft burns up at 35km even before the flammes effect appear with just 3kPa of dyn pressure :/

The only way I managed to reenter this was by pointing it backwards ! Once it hit 40km it started stalling and doing flips, but it finally reentered without burning up ...

Edited May 21, 2015 by luckyhendrix

[Nerd1000]

Hello, does anyone have a SSTO mk2 size plane that can reenter without burning up ?? my craft here cannot reenter anyway I try ... I've tried very shallow reentries and more aggressive, but even with the very shallow one my carft burns up at 35km even before the flammes effect appear with just 3kPa of dyn pressure :/

The only way I managed to reenter this was by pointing it backwards ! Once it hit 40km it started stalling and doing flips, but it finally reentered without burning up ...

Try a 'skip re-entry'. Use the FAR flight data window to angle you ship to produce as much lift as possible. Rather than flying down into the atmosphere steadily, you should descend until your lift reverses your vertical velocity and 'skips' you back up into the upper atmosphere. This will give your ship time to cool before you begin to fall down again. Rinse and repeat. With each skip you will lose speed and altitude until you are in air that is too dense for the skipping to work- from there you need to fly the ship like a plane.

The one thing you need to look out for is if your vertical velocity is too high after a skip you'll come back down too steeply, so its best to watch the vertical speed gauge and reduce your angle of attack once you're satisfied with your upward speed.

[Wanderfound]

Thanks, but I actually meant about the stability in launch without fins and such. Technically, all we need is to have the natural CoP lower than the CoM, and maybe starting off with a lower TWR?

1) No sudden changes in cross-sectional area, especially near the nose

2) Gimballed engines.

That's it. Launch TWR was something like 1.7, throttle was wide open the whole way up. Not so much as a wobble; I deliberately flew a rough large-AoA profile to test it, and it was perfectly stable even at 20° off prograde.

- - - Updated - - -

Hello, does anyone have a SSTO mk2 size plane that can reenter without burning up ?? my craft here cannot reenter anyway I try ... I've tried very shallow reentries and more aggressive, but even with the very shallow one my carft burns up at 35km even before the flammes effect appear with just 3kPa of dyn pressure :/

The only way I managed to reenter this was by pointing it backwards ! Once it hit 40km it started stalling and doing flips, but it finally reentered without burning up ...

http://images.akamai.steamusercontent.com/ugc/26239284372871825/3D087E8DD82DD3F1165812FE9127EC0BC32D6927/

You should see some flames, but there's a long time between visible flames and melted wings.

Reentry demo:

Javascript is disabled. View full album

Edited May 22, 2015 by Wanderfound

[Cinocal]

Use an air brake. You won't spend so much time at boiling speeds.

[Wanderfound]

An early-career survey aircraft that might be of use to some:

Javascript is disabled. View full album

Craft file at https://www.dropbox.com/s/ihkwtlb2u737stw/Kerboflyer.craft?dl=0

[DaMichel]

My latest invention. An orange tank lifter. Can manage to bring it to a 100 km circular orbit and still have a few hundred DV left.

https://www.dropbox.com/s/rghddzj0xykaq43/Big%20Spaceplane%20XT.craft?dl=0

Be warned though when you pilot it. For some reason i get asymmetric flame out at over 66% throttle. It also suffers from asymmetric wing flexing.

It is made of all stock parts except for the engines. The config i posted earlier was of course faulty. This is the new one. I also scaled the mass. So now it is really like a 4x cluster of normal RAPIERS.

+PART[RAPIER]:BEFORE[AJE]
{
	@name = SuperRapier2x
	@title = Super R.A.P.I.E.R. Engine

    %rescaleFactor = 2.5

    @mass *= 4.

	@MODULE[ModuleEnginesFX],0
	{
		@maxThrust *= 4
	}
	@MODULE[ModuleEnginesFX],1
	{
		@maxThrust *= 4
	}
}

Btw. i haven't tested it with the new nuFAR yet.

- - - Updated - - -

Hello, does anyone have a SSTO mk2 size plane that can reenter without burning up ?? my craft here cannot reenter anyway I try ... I've tried very shallow reentries and more aggressive, but even with the very shallow one my carft burns up at 35km even before the flammes effect appear with just 3kPa of dyn pressure :/

Sounds like there is a bad part which has a low max temp or thermal mass (heat capacity). What you can do to identify it: Go to debug options F12. Go to thermal physics options. Enable thermal data display in part menus. Now you can right click on parts to see all relevant info.

Edited May 22, 2015 by DaMichel

[luckyhendrix]

Well I still have problems, with my SSTO, I don't like using stock airbrakes, they feel so cheaty :/.

I would be really interested if someone could show me a design that can fly for a relatively long duration of time at Mach 3 like the SR71 (by that I mean at least 10 minutes). Now with the heat I have to completely rethinkt my spaceplane ascent profile, because spending too much time accelerating past Mach 2.5 is deadly

[kcs123]

If it is too hot, go higher. You will need to build stable plane for high altitudes though. That is main reason why I tent to build planes with big ugly tails