Rotorcraft Workaround

[K^2]

There seems to be an aerodynamics bug that currently prevents rotors from working properly, but so long as each wing moves as an individual object, it works as it's supposed to, so separating the rotor blades prior to take off seems to work. Briefly. This definitely needs more work to ensure that the craft isn't taken by the Kraken almost instantly. Still, as it might be the only way to fly on Eve and Jool, this might be an avenue for further experimentation.

 

[J.Random]

Sorry, OT, but is the music from stock KSP2? It sounds suspiciously similar to one of the Cities: Skyline themes.

[Jacke]

It's like watching the early days of flight, pre-1914.  But in vibrant colour.

[K^2]

1 hour ago, J.Random said:

Sorry, OT, but is the music from stock KSP2? It sounds suspiciously similar to one of the Cities: Skyline themes.

This one? There is definitely similar use of strings, but that style goes back to a lot of adventure films, and from there back to classical music. If there is something more similar in Cities Skylines, I missed it.

And yeah, this is standard music playing when you take off from Kerbin. There are separate themes for different situations on different planets. Not really sure how detailed it is, but it works pretty well where I've seen it used. I'm sure it'll get old eventually, though. Especially this particular piece if you have to restart a lot for a particularly tricky launch.

[Nuke]

all those truss segments and struts seem to be like kraken treats. sort of like when you shake cat treats and they all come running, except its the kraken. 

Edited March 1, 2023 by Nuke

[K^2]

7 hours ago, Nuke said:

all those truss segments and struts seem to be like kraken treats. sort of like when you shake cat treats and they all come running, except its the kraken. 

Indeed. I just haven't been able to come up with a better bearing yet. Well, not strictly a bearing, necessarily, but I do need some way to constrain the roots of blades to the hub.

I do want to see if maybe we can build something like the old style rotor bearing here, using round structures and wheels. That will be a much larger craft, however. Still, that's probably what it's going to take.

[Majorjim!]

Do OG KSP type bearings work? Like RCS or thermometer bearings. 

[K^2]

40 minutes ago, Majorjim! said:

Do OG KSP type bearings work? Like RCS or thermometer bearings. 

I have not experimented with these enough. There are no thermometers yet, so that's out, but there are enough of small size parts that might be compatible. The underlying physics is largely the same, so the same principles should apply, but the tuning is different, which means other parts and connectors might be more Kraken-sensitive, which leads to problems.

I've also encountered some bugs where certain configurations of connections and offsets are just refusing to stay attached, so you get entire sections just fall off your craft. That becomes more likely as you increase the complexity of the part attachments and offsets, complicating this whole matter. That's why I am leaning towards going simple and big, using wheels on round parts, for the next set of experiments.

[whatsEJstandfor]

@Bej Kerman well well well

 

[Klapaucius]

Interesting. I experimented with those as well and noticed the lack of lift.

[RocketRockington]

That's kind of concerning.  No piecewise calculation of lift?  KSP1 did it on a per part basis, which, while not ideal, at least allowed for kraken drive rotorcraft and then real ones with breaking ground.  I had kind of hoped KSP2 would implement an even better system like FAR or MSFS.  It sounds like at best.maybe the per.part aero calculations are using the net velocity of the craft and not the part velocity though.  I guess time will tell.

[BobTheYoungFish]

Made an attempt at this today with reasonable success. Separating the blades from the main craft works to generate lift but was having the same problems as @K^2 where they would escape their cages when spinning fast enough. Building a cage the entire length of the blade and a few struts made it much more stable, enough to get up to 1km on Kerbin and could've gone higher.

Spoiler

The center blades are attached to a structural panel that's trapped as tightly as possible by a cube of panels. The top and bottom wings are attached to the main craft and strutted together.

On 3/1/2023 at 11:07 PM, whatsEJstandfor said:

@Bej Kerman well well well

 

I believe the vertical speed from that clip is from the engines - not the wings. With gimbal and SAS on the engines point slightly downwards trying to correct for the spin, generating enough thrust to take off.

https://i.imgur.com/dt2OTwZ.mp4

 

[K^2]

6 hours ago, BobTheYoungFish said:

Made an attempt at this today with reasonable success. Separating the blades from the main craft works to generate lift but was having the same problems as @K^2 where they would escape their cages when spinning fast enough. Building a cage the entire length of the blade and a few struts made it much more stable, enough to get up to 1km on Kerbin and could've gone higher.

I have been able to climb to 40km on Jool. The density at that altitude is below that of Kerbin at 10km, so it should be possible to climb at least that high on Kerbin with the same design. Here is a video, but mind the minor spoilers for Jool.

Same general idea, though. Large cages to keep the blades from flying off. I did end up going with a pair of them, which might be unnecessary, but it was easier to build something symmetrical like that for me.

The limiting factor is still the centrifugal stress on the blades/cage. The lift force is roughly proportional to drag despite pressure variations, so in theory, as the atmo gets thinner, all you have to do is spin faster to maintain the same lift, and since the reaction wheels provide constant torque, your craft can spin as fast as necessary. Of course, until it simply fails from stress. A better cage design ought to be able to handle more stress, and consequently, allow for faster rotation and higher ceilng.

I don't know if this is of any use on Kerbin, but I'm trying to figure out how to build a multi-rotor carrier for an ascent rocket. That should make return missions from Eve and Jool possible. So naturally, I'm trying to gain as much altitude as possible in both of these cases. Jool's atmosphere is not so bad, actually, due to low density, and the surface gravity is low, but escape velocity means that even if you don't have to fight against the atmosphere, the return rocket has to be quite beefy, and that means a big rotorcraft carrier...

[Chilkoot]

On 3/1/2023 at 2:14 AM, J.Random said:

Sorry, OT, but is the music from stock KSP2? It sounds suspiciously similar to one of the Cities: Skyline themes.

Definitely some thematic similarities with the horn fanfares and the staccato string quasi counterpoint thing in there plus some tympani punctuation (no snare in Skylines and no prevalent winds in this  KSP snippet, though).  There are some sections in the Skylines theme with a progression that's *close* (arguably).

More of a style thing than a motif thing though - like you'd never see Valtonen file a copyright suit over it, however I've seen this comment at least 4 times now in different places so the similarity certainly "strikes a chord" with people

[K^2]

A shout-out to MinerBat on YouTube (I don't know if they have an account here) for building a full return mission to Jool. It uses a Kraken drive for the final bit of flight with rotors to gain altitude enough for the Kraken drive to work, but even with that drastic reduction in weight of the final stage, this is a very ambitious build, and it's a good watch.

 

[B15hop]

This is so KSP lol. I love it!

[Strawberry]

Surprised someone did it! Congrats to MinerBat!

[Janeer]

First of all, I want to thank the person who posted the rotorcraft workaround on the KSP forum. As someone who loves tinkering with different aircraft designs in the game, it's always great to see new ideas and techniques being shared by other players.

I've tried out the workaround myself, and I have to say that it's a pretty clever solution to the issue of building functional helicopters in KSP. While it might take a bit of trial and error to get the rotors working just right, the end result is definitely worth it. There's something incredibly satisfying about seeing your creation take off and hover in the air, especially when you've had to put in some effort to make it happen.

Edited April 3, 2023 by Janeer

[minerbat]

On 3/30/2023 at 12:44 AM, K^2 said:

A shout-out to MinerBat on YouTube (I don't know if they have an account here) for building a full return mission to Jool. It uses a Kraken drive for the final bit of flight with rotors to gain altitude enough for the Kraken drive to work, but even with that drastic reduction in weight of the final stage, this is a very ambitious build, and it's a good watch.

 

yes i have an account here but somehow the mention didnt notify me so i just randomly found this when looking up myself in the forum's search function so hi, i might be like a year late but i am here anyway

[K^2]

On 2/14/2024 at 1:48 PM, minerbat said:

yes i have an account here but somehow the mention didnt notify me

I was trying to get an actual mention in, but your name wasn't showing up for some reason.  Anyways, glad to know you saw it eventually. I'm the one who posted the original electric rotor ascent on Jool video, and I was super excited that somebody made a working mission out of it.