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mattihase

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Posts posted by mattihase

    Weekly Challenge #53: Build a Seaplane!

    in Challenges & Mission Ideas

    Posted

    Funnily enough I was working on something like this over the weekend. Only really hits the first objective and it's not very practical but I had a lot of fun working on it so I may come up with something specific for the challenge later this week.

     

    Aside from the tanks/tank intake on the engine block, most of that is empty tank. So... yeah, if you want bouyancy you really do need a hell of a lot of empty tanks.

    Savoia S22 Seaplane

    in The KSP2 Spacecraft Exchange

    Posted · Edited by mattihase

    3TlsxFx.png

    The Savoia S22, a loosely adapted tribute to the Savoia S.21 seaplane from the movie Porco Rosso.

    The S22 was my first attempt at attempting a Seaplane in the game since they've fixed bouyancy, and because I'd just watched Porco Rosso I figured I'd have a go making something based on the (fictional) S.21 seaplane from that. Specifically I decided to try and evoke its apperance post-rebuild. However I didn't really fuss over scale that much, just hitting the rough proportions, and because of that I decided to name this as its own distinct design rather than passing it off as an actual recreation.

    Note: I'm putting screenshots from throughout the craft's development so some bits may be missing or present in some screenshots, and I didn't notice and fix the gap in the tailplane until I shot the stunts video.

    Design & Jank:

    pXGYb7v.png

    Spoiler

    The main fuselage has a lot of bouyant empty tanks, a cockpit and room for a passenger up front, I also took care to replicate the sand-coloured underbelly as best I could, as well as the italian flag on the tailplane. In the place of the ram air turbine (little emergency generator windmill) to the side of the cockpit is a dimmed spotlight in the same yellow colour, and I included a radio antenna in the place of the pilot's optical sights. Sadly, there are no machine guns in the game yet to aim at stuff so that's the best you get right now.

    The wings and engine are mounted on decouplers (which unfortunately can't be removed from staging at the moment. I'll be honest the wings are a lot bigger than would be accurate but do mantain both the swept shape and large wingtip elevons. The pontoons continue the sand-coloured underbelly look though for these I swapped around the colours as the radial attachment point on the empty methane tanks is in the secondary colour. The engine block is quite loose. It's supposed to have the underside intake that I used the inline intake to represent, but on the original design this intake hangs down in front of the wing. Ah well, it still looks decent. Of course there's no propeller engines in KSP2 so a J-33 and a somewhat propellery looking front intake will have to suffice for now.

    H8Abmd6.png

    While it was quite nice replicating the design in spirt, from a practicality standpoint KSP's limited selection of what aircraft physics it simulates and the fact that I can't actually make anything more lighter than it is empty, posed significant problems when it came to getting that overslung engine to not just nosedive the plane to the bottom of the sea. It did force me to do a lot of tweaking of the engine's angle reletive to the craft and its thrust limit and, well...

    pXGYb7v.png

    So... normally, having the COL in front like that would cause the plane to just keep on flipping over backwards, but... the top-mounted engine is already keen on making it flip over forwards, so... combining the two together ends up basically spitting out an almost normal controlling plane. Well, almost. It feels different but not unpleasant to fly.

     

     

    Takeoff & Landing:

    EsNRRlD.png

    Spoiler

    The S22 takes off at about 26m/s (or about 60mph), just above stall speed.

    While it doesn't like to nose down in flight, it really likes to dip its nose in the water with the engine on full thrust. Probably a combination of the difference in drag between water and ground and the wings not going fast enough to generate enough pitch torque to offset the engine's contributions. I find that with the engine on 55% thrust the craft is capable of reaching takeoff speed without faceplanting into the sea, so for ease of use I just put a thrust limit on the engine that makes full throttle that.

    qRYaRbk.png

    The S.21 from Porco Rosso is described as being "difficult to take off but incredible during the air", and while the S22 does have a similar weak spot when it comes to taking off, the amount of space it needs to take off isn't all that bad. During testing I landed it on and took off from the lake to the north of Launchpad 1, and the KSC canal system, which it just about barely has the space the S22 needs to land in and take off with if you choose your stretch carefully.

    There are some control quirks to take-off. You need to be pitching up from the moment you light the engine to prevent a nosedive into the water, and due to a slightly annoying glitch regarding the placement of the centre of mass in the angled tailplane being flat broken in positioning, the plane likes to turn slightly to the right at all times, so you have to correct that in order to get up to takeoff speeds. Hopefully in future versions of the game, this incorrect mass position is fixed.

    EsNRRlD.png

    Landing is also a bit finnicky. The S22 stalls very easy if you cut the engine, so the best thing to do is to fly down to within a couple meters of the water and slowly reduce speed until it drops. You can also stall it from a similar height and land in the water without any damage, she's a pretty sturdy gal.

    EY481hz.png

    Finally, the S22 much like its inspiration does not have wheels so make sure you launch it from the boat launch instead of the runway.

     

    Flight Performance & Video:

    cu9NJXy.png

    Spoiler

    The S22 hits a really nice balance of being responsive/manouvreable, and being stable, most of the time.

    Because of its weirdly placed CoL, there's a degree of roll, where if you pass it then it does all of the pitching you need for a banking turn on its own. It can pull up from stalls incredibly quickly too, which is handy because it glides like garbage. It has difficulty mantaining speed when in a steep climb, but quickly picks it up again if you level out, and indeed the best way to build up speed is to angle a bit below the horizon to get the engine horizonal and let the speed and lift do the work to keep it level.  Most importantly the wingspan is comfortably small enough to fit between the two car parks either side of the space centre's first two bridges. With a little bit of practice you can slip under them easily.

    On the stability side of things, if you take your hands off the controls it mantains speed and slowly climbs. Because of the offset mass tailplane bug aforementioned it also gently turns to the right. Again, hopefully with the next update that'll be fixed but it doesn't have that much of an effect (less than 2% trim worth of torque) unless you're going long distance. And as I mentioned above, this stability is there even without SAS too. It's just really nice to fly.

    OK, but what sort of stunts can it pull?

    Quite a few. It can do various rolls, though if you want to get anything resembling an aileron roll out of it instead of a stand-up guyised barrel roll, you need to pump the engine limiter up to 100%. It can do a Split S, but it's not too great at roll-off-the-top turns, however it's really in its element with stall turns, those are a lot of fun to do.

    Once you get used to the feel of it, you can really put on a decent airshow for the kerbals at the space centre.

    As far as pushing for performance goes, at standard 55% limited engine power the S22 can mantain 70m/s in level flight, providing you give it 44-60% pitch down trim (I use trim controller for this, and add trim progressively in blocks of ~10%) to hold the angled engine in line with the prograde marker. When it comes to how high you can fly it... it doesn't climb all that fast so I didn't stick around to work out what height it would stall at, but it seemed to start losing speed in level flight at around 5000m up and steadily lose it above that, so I suspect it'd stall at some point between 6000m and 10000m up. Not that you'd want to spend time going that high.

    DdGjQMC.png

    Finally, as far as performance goes, taking it off and getting it up to about 2000m-3000m, it hits a peak burn time of 1 hour and 20 minutes. At 70m/s that's ~336km, probably comfortably 330km if you want to leave a large safety margin for a powered landing, which I would recommend. This'd get you about 1/3 of the way to one of the poles.


    As noted I mostly keep the S22 with a 55% engine limiter to make take-offs possible. It's more that possible to fly it with 100% engine power, which raises the cruising speed from ~70m/s to ~120m/s and makes a lot of the more finnicky aerial manouveres that benefit from inertia a bit easier, but otherwise handles pretty much the same way. Being on low fuel doesn't effect the handling much either.

    Closing thoughts:

    I'm rather pleased with what I achieved with the S22, not just as a visual homage to the S.21, but also a plane that, jet engine aside, feels like it really captures the spirit of that sort of plane too. Its speed and handling feels about right, I really like the detail work I was able to add, and I think most poigniantly the fact that getting it to fly pulled from my knowledge of aerodynamics, or at least the game's aerodynamic model, felt appropriately pioneering. It's also just fun. I'm gonna definitely keep this one around for when multiplayer drops.

    Ov5QP8n.png

    Download Link: https://drive.google.com/file/d/16hA3IO-08gPiphQQojxPGyBUitV9NxF-/view?usp=sharing

    COM position for angled tailplane is incongrous with geometry

    in Parts & Vessels

    Posted · Edited by The Space Peacock

    Reported Version: v0.2.1 (latest) | Mods: Commnext, Microengineer, Trim Controller | Can replicate without mods? Yes 
    OS: Windows 10 | CPU: i7-10870H | GPU: RTX 3070 | RAM: 16GB

     

    COM for angled tailplane (Tail Connector B) is offset such that having the connector pointed to the side places its mass in the middle whereas pointing it up/down offsets its COM to either side (demonstrated in video). This has the result of giving any craft including this tailplane the tendency to roll if it is used as intended.

    Expected behaviour would be that pointing the tailplane to each side would shift the mass that way.

     

    Included Attachments:

     

    Control Contrails on a per-wing basis

    in KSP2 Suggestions and Development Discussion

    Posted

    I tend to do a fair bit of constructing wings from multiple wing parts, either because I want to go for a shape with more than 4 points on it, approximate a curved ending, or even just include 2 control surfaces on the same wing.

     

    While the contrails are a nice visual touch it's quite annoying that whenever I make one of these composite wings, they end up producing a lot of contrails from what is often the dead centre of a wing. I think it'd be great to allow designers a little extra control over the contrails so we can tidy up designs to make them look their best.

    Base falls through ground - No timewarp [Craft launches into space away from the base into orbit. Returning to Base its under the ground]

    in Environmental & Terrain

    Posted

    Reported Version: v0.2.1 (latest) | Mods: Commnext, Microengineer | Can replicate without mods? Yes 
    OS: Windows 10 | CPU: i7-10870H | GPU: RTX 3070 | RAM: 16GB

    Landed a lander on this spot in the mun highlands. Tried swapping away to a relay satellite in orbit and then back (I'm playing with Commnext) and when I swapped back the lander kept on spawning below the terrain.

    Works regardless of mods. To replicate it using the included save, swap to any other vessel and then back to the lander on (or rather below) the surface.

    Included Attachments:

    theonewhereyoufallunderthemun.zip

    Developer Insights #23 - Black Hole Sun

    in Dev Diaries

    Posted

    1 hour ago, Oak7603 said:

    My apologies, by wobbly rockets, I meant the rockets that start wobbling on the launch pad and then explode and then a relaunch fixes it. @herbal space program in the post above is proof taht this is still happening.

    I feel like this is more an issue of lack of physics easing in the current game than the structural integrity being borked. If you can get past the first couple seconds (such as using cheats temporarily or launch clamps) it usually sorts itself out soon after.

     

    Engine wise it's definitely among the more important features left that need to make their way into the game.

    Why play (suggestions)

    in KSP2 Suggestions and Development Discussion

    Posted

    I definitely wish the island runway had more... interactivity? Like, it definitely feels like a step backwards from KSP1 where you could climb the tower and had hangars to go in and out of.

    If it could be used as a test site for experimenting with adding colony bits on to make it suck less, like not necessarily as a tutorial but as a testbed deployment site or something along those lines, that would certainly make up for it though.

    Why play (suggestions)

    in KSP2 Suggestions and Development Discussion

    Posted

    On 4/6/2024 at 10:23 PM, kfsone said:

     (*cough*)

    I don't think I've seen a github readme file collapse into a pile of code before now. They must have dropped support for something in the last 9 years or so.

    On 4/6/2024 at 10:23 PM, kfsone said:

    I've just been flying around Kerbin in a jet and enjoying the scenery, but I had two annoying thoughts itching to ask themselves: how come all the kerbals live at ksc?; why would someone else come here? Well, hopefully you can practice your base building on Kerbal for the scenic sunrises and views and etc. But if the game added aircraft missions at the moment that would quickly irritate me because the flight controls are still wip (I hope).

    Definitely I can imagine a little side mission chain dedicated to setting up a prototype base somewhere on kerbin and set up a supply route to it could be both a good way to integrate setting up more stuff on kerbin to the game and make non-space-planes actually be relevant for a moment rather than completely just being beautiful looking bridge-flyer-underers.

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