Wtf is up with Helicopters?

[Baal]

I tried the last two days to debug shaking Helicopters and no matter how I change the center of mass they all end up shiking violently and ending up even destroying their own rotors mid air.
My Helicopters all had the Center of gravity some block behind the rotos and no problems at all.
All designs that worked flawlessly Months ago shake themself to death.

Now all I can find is comments on other posts that the center of gravity should be positioned under the Main Rotor but changing the Center of gravitiy don't change a thing.
The only success I got was to reduce the amount of Rotor blades but that came with heavily decreased lifting capability.

So just to test out my theory about the Rotor blade numbers I tried the PRESET(!!!) Helicopter.
It starts shaking horrible too, even without any changes!

Are Helicopters just completely broken right now?!

[GhostBlackMor]

Wow man, maybe something wrong with your game, I just tested my helis and it's stable as always, too much RPM will make it shake violently, on my designs I have to ajust the RPM to keep the heli stable.

[Baal]

I even reinstalled it it did not change anything. And as I said even the preset heli is broken. And the thing that too much RPM will make everythign shaky is new behaviour that didn't existed a few months ago.

No combination of low RPM high rotor-blade-amount or High RPM low-motor-blade-amout is completely shake proof for me. At least when wind comes there will be a lot of shaking.

On the offical bug tracking site I found mentions of this problem too after posting this.
In my external point of view I can only guess that the physics simulation at its current state is not fast enough or teh gyro calculations are to slow. My PC with 3700X, 16GB RAM, 1080 Ti and SSD is probably not the problem.

Or maybe simply the physics are broken because the shaking is very similar to shaking of controll surfaces under water (that exists even with unpowered no signal controll surfaces).

I really hope it will be fixed together with Multiplayer.


Can you maybe upload one of your 100% working Helicopters? Because it would be very interesting if it shakes when I fly it.

[Ra-Ra-Rasputin]

The 30 or so helicopters i have on hand (15 of my own making) work fine, but i can tell you what's with the violent shaking:

When you're outputting a significant amount of power to the prop without providing counter-rotational force, this will cause an effect called torque-turning, because of Newton's third law of motion: For every action, there is an equal, and opposite reaction. You're putting in a lot of force to turn that prop at a fast rate, so naturally it will turn your helicopter to the opposite direction.

The gyro will react to this and try to wrestle it back into order, at that point if your prop is at the speed to cause it to resist this motion, the gyro will force itself to react quickly, which causes it to overshoot, which is then worsened by your misaligned center of mass. It will be made even more worse when the engine isn't locked to provide a stable rotational rate, as the rotational correction will cause drag and provide uneven rotation rates, which will eventually cause a violent cascade of shaking as the gyro tries to wrestle against the forces in question.

What this basically boils down to, is that you can "fix" this by simply limiting the force the gyroscope corrects the roll with by dividing the value of the stabilized roll going into the rotor by a relatively large number, such as 5. It's fixing the effect and not the cause, however, and it limits the gyroscope's ability to correct roll properly, which means your helicopter can't recover from dangerous situations as well.


If you're not sure what i mean by stable rotational rate, check out these 2 things:
https://steamcommunity.com/sharedfiles/filedetails/?id=1940469968
https://steamcommunity.com/sharedfiles/filedetails/?id=1940483240

[Baal]

Ok I tested them both, they are both shaking hard as soon as a bit of wind comes up.

And the thing with the rotational force: A few months ago it was simple by just putting in an T Pipe that give the same connection (and thus the same RPM and available power) to the tail rotor and the main rotor. Both had the same RPM and together with the gyro you had everything smooth.
Back then the gyro did not overshoot or something like this. I even built an simple Osprey like helicopter (without tilting) where you need mathematical blocks after the Gyro between left and right rotor for rolling and it worked completely fine.


This is my new helicopter that I designed out of my old black hawk inspired one to get center of mass to the front but it did not cancel out the shakyness:
https://steamcommunity.com/sharedfiles/filedetails/?id=1993169393

Here is my old design modified to not overheat the engines (Engine heat got increased over the months that was expected) that worked like a charm a few months ago:
https://steamcommunity.com/sharedfiles/filedetails/?id=1993173931

Both of them doesn't loose RPM when climbing because engines are powerfull enough.

The Shakyness is the same but not as bad as on your two demo helicopters, probably mainly because the mass and thus inertia is higher.


Also what I observed: The shakyness is not existend 100% of the time but as longer as you fly the more often and longer it will be.

[Ra-Ra-Rasputin]

The first of the simplehelos shakes because it has issues spooling up the engine too hard, but the second one doesn't, even with 100% wind setting on creative for me. It does overcorrect slightly for a momentary tremble in the air, but it never shakes itself in a violent manner where it becomes uncontrollable. Even that can be removed by increasing the divider amount in its setting to curb the gyro roll input.

Anyhow, i made a simple PID, added a proper engine control and sanitized your roll input. Now its ridiculously overpowered setup can do barrel rolls without shaking

https://steamcommunity.com/sharedfiles/filedetails/?id=1993222849

[Baal]

I appreciate your help but yaw is completely overdriven now, probably because the roll is divided but yaw not. When I yaw, I get indirect rolling...
Also the shaking (especcially with wind) is exactly the same. I tired the same devider on yaw which reduced the overdriven yaw but all that does not help the shaking.

What benefit has this PID engine controll? When I use 100% throttle I get the same amount of overpowered engine performance just with less disturbing noise?


For now I guess the game is simply bugged and do different behavior for dieffernt people. I also observed problems where the Helicopters just completely ignore any input for like 5 seconds.
I can only guess that maybe gyro calculations or something different is broken.
Already when spawning the Helicopter in hanger where it falls like 2-3 blocks the rotor inputs wiggle A LOT which was far less a few months back...


Edit: I installed digital numbers and tried to understand the ignoring of my inputs.
clearly the gyro outputs the correct number that i input buit it just gets compeltely ignored by the rotor or physics. The engine RPM did not fall. This especially happens when diving the nose and then it just ignores ALL input (pitch, roll and yaw) and falls straight to the ground.

Probably some calculation task get lagged out...
F1 does not iondicate any performance problems...

I will wait till Multiplayer update maybe then this will be fixed (i mean they are doing heavy physics calculation changes with that update)...

[Ra-Ra-Rasputin]

The game is not bugged from the helicopter standpoint.

You're putting in 5 times the power need with an obscenely sized blade meant for a helicopter 3 times as large, so your starting point is already absolute insanity. Likely the shaking you're experiencing is actual performance stutter or similar as i can't get that thing to shape with the PID stabilization, nor can i get my electronically stabilized engine to shake. I can record a video of this if you wish.

The PID forces the engine to stay at a set RPS instead of working on a drive-by-wire style throttle that it does by default, the throttle lever controls the target RPS by a multiplier of 20 on its value.

I commonly browse the bug report boards and here, and i have literally never seen anyone mention that anything in the game would ignore input (aside from obviously losing control of a car or something similar), which is leading me to believe that it could be something interfering on your end.

...and then i read on to your edit.

The helicopter blade cannot function properly as a vertical blade without some sort of special systems, such as lifting wings to keep it in place. It will, and only can work in an upright setting and at a horizontal tilt less than 60°. Rash and completely insane manouvers like barrel rolls require complete loss of control for most of the manouver.

Rotating the helicopter's nose fully down will make you completely lose all control because of an effect called gimbal lock. When you're tilted with your nose completely down, your yaw and roll will be on the exact same axis which makes the situation unsalvageable. You would meet the same issue in real helicopters.

EDIT: Since i'm scatterbrained, i forgot to mention, the best way to curb the sensitivity of anything is to tweak the numbers in the seat, instead of actually attacking the stabilization. If you find it very hard to use helicopters, keep the auto-hover on.

[Baal]

Rotor meant for a Heli 3 Times the size? What on earth is oversized on the rotor of my two helis ? My Black Hawk inspired one is very proportional with the Rotor and the New test heli which is more inspired to an Hellcat would look like an absolut joke with the next smaller one. Also with the next smaller ones it would have problems even taking of or lifting.
And 5 times overpowered??? How on earth would you lift anything or even accelerate with 1/5 of the power? Helicopters need huge amount of power in reallife because they constantly lift them selfes instead of Aircraft that only need to gain speed so that the wings can do the lifting.

The "NewHelicopter" works fine with only one Aircraft Engine, I know that because I built it that way yesterday. The two Engine Version simply was to eleminate the posibillity of loss of Engine power when doing maneuvers with increased stress.

And ALL the changed behaviors that in my opinion don't seem right just simply were simply not there like ~2 months ago.
Such things didn't were there like ALL the time back to when Helicopters in Stormworks only had positve main rotors back when developers did think that would be good enough and I and others discussed with them so that we get realistic collective controlls.

And I wrote that the controll ignoring problem can reproduced easily with tilting it within realistic angles but happens mid normal flight too. Im not nose diving that thing 90 degrees to the ground...

I belive that the Helicopters work fine on your PC the thing is I just don't have a clue what is the reason for this shaking etc. it can only be some calculation thread or similar.

My PC performance is definetly not the reason and reinstalling and deleting the Appdata folder did nothing. It seems the best chance for me is to wait for Wednesday.

[Ra-Ra-Rasputin]

The helicopter rotor you're using is something you would see on a Chinook, which is know for its completely absurd sized blades. For a helicopter of the size you have the large rotor is more than adequate i assure you. On that note, i definitely would love a non-heavy middle ground between the two.

And it's 5 times overpowered, because you can lift it with one small engine running at a high RPS rate, or a pair running at much more reasonable rates (which would make it only 3 times overpowered). The medium engine is intended for running high speed props, and a single one could easily run both ends of a twin-bladed cargo helo :)

You're not facing engine stress, you're facing the engine's response time, that's accentuated by lack of gearing. The diesel engines take time to spool up and generally speaking you do not want to adjust their throttle, only the collective. As for gearing, the aircraft engine puts out quite considerable amount of torque, and even with small engines you can easily go for 1:2-1:3 ratios depending on what they're lifting.

~2 months ago or so was before the latest engine rebalancing, which adjusted engine power curves and made them give out significantly more torque at higher RPS, instead of full on torque at 2 RPS as they used to.

I still believe there's a chance of user error or something. I'd love to see a video of you experiencing these issues so i can see it for myself. I don't intend this to be calling you out or anything, i'm genuinely curious why we're getting separate experiences.

[Baal]

OK the new update did two things:
First the shaking issue is far more comprehensible and I am able to reproduce it much better. before the update 10 it was mainly random: When turning the shaking was truning me on the roll axis no matter how sharp (or not sharp) I turned and moved. It was more or less just random.

Now its clearly when doing high angle of attack moves (if you can call them so on helicopters as well?). Easy to reproduce especially with wind: Dive the nose 45° against wind, gain spead and pitch up. It shakes. But that is mainly when doing verry agressive maneuvers. Now the instabillity (shaking) could be explained/justified with too agressive maneuvers which would make an real helicopter going instable too.

And now the secod thing:
I can completely (as far as I tested the last few 30 minutes) eliminate the shaking issue on helicopters that I tested with with the new gyro setting:
Min Throttle 20%
everything else 85%

The Helis still feel very agile and I hope this really fixes the thing (as I saidf I only tested ~30min).

The Preset Helicopter still shakes, and as soon as I apply my "Gyro fix" settings I could no longer reproduce the problems.

My GUESS is that either the physics changed in the last few months, or the gyro was changed to be much more agressive.
Now with the new update the gyro can be configured on how agressive it should be, which is good!

[Ra-Ra-Rasputin]

Just to put it out there, 45° is an absurdly extreme attack angle and not viable for any helicopter. The prop tilt at 15° and body tilt at 15° is on the edge of ridiculous already with any real world or in-game example i can imagine. To put it into perspective, (quick headcount) with a 15° bodytilt in a 20m helo you'd be moving down more than 2m as the pilot.

The basic gyro available in the game is a generalized model that is meant to be an all-rounder. If you absolutely want a chopper that can do aerobatics, you'll need much more complex systems that can understand and deal with extreme situations.

That is on top of the fact that with heavy body tilting you'll be presenting your front toward the direction of travel which increases drag to the degree which means you can't maintain speed or lift, and any and all lifting surfaces are now at a steep downward angle. There's a theoretical maximum that you'll hit sooner or later. A reactive fin system will allow you to push further where the fins provide lift as if wings at deep attack angles, but even they can go only so deep.

Instability of the engine RPS output causes significant instability with the rotors, especially if you have (as you should have) increased gearing toward the props. A constant sway of 0.05 can be catastrophic, as it triples even with one 1:3 gearing. A PID or a microcontroller holding the engine at a stable setting means you get a more stable helicopter as a result. They're not simple, mechanical beasts after all.

It's less that the physics has had changes, but rather the engines have had changes in the last few months. For absolute best results, you probably should look into making your own gyro. Look up the PID guide on the guides section.

[Baal]

Uhhhm 15° Body tilt extreme? That is like standard cruising angle. An real helicopter can do that in a fracture of a second from "standing still" in the air. There are tons of videos on youtube of large and heavy military helicopters like Black Hawks or Apaches that are doing extreme agressive maneuvers without problems.
Just one of the carziest examples: https://www.youtube.com/watch?v=JjOX59zKgAA
And i didn't even searched for russian ones, those will probably even more ridiculous.


I get what you are saying about engine RPM but for exactly thats the reason I have overpowered engines that are constantly in their RPS limit so the RPS dont really drop.
Also when talkin about realism, real rotors and their whole gear system are far to inert to fluctuate extremely fast.


Also I want to clarify I don't wan't to say that you should be able to take parts together and voila expect you have an realistic behaving helicopter that can perform those agressive maneuvers. Especially your telling over the generalized gyro is very true.
Also this game currently doesn't seem to aim to be an copmplete realistic sumulator like builder and that is fine.

The whole thread was to ask wtf is up with helis because everything worked fine 2-3 Months ago with the standard gyro and was not really understandable and definetly not simple to fix. I figured it out now through the Gyro limits (that are working in contrast to just dividing the signals) and with the new update you can fix the things to be easy and problem free like before.


Also the thing that the ingame preset helicopter has the shaking problem when doing agressive maneuvers should be fixed, because its the first Helicopter that people will use in career mode. And thast thing should be mostly fool-proof.


And if for somewhat reason I am the only one (or one of very few people) that expiriences this helicopter shaking than I really want to know that and especially want to know how to fix that. Because reinstall and deleting Appdata folder together didn't change anything.
The best common base to test this is simply the preset helicopter.

[Ra-Ra-Rasputin]

Standard cruising angle for helicopters is about 0°. That's because they tilt the rotor 3-8° to fly, and it's very uncommon for any of them to have large amount of body-tilt unless they are in a hurry. There are still older models and very barebones variants that do bodytilting, but your bog-standard Bell 212 for instance doesn't need to tilt its body at all for any 6 axis motions or cruise, probably also a reason why it's so common to see it used for medical rescue.

The key here is "military helicopters". You wouldn't compare your average car with an armored personnel carrier, even though both are meant for ferrying people around and have wheels. Apaches and modern variants of Blackhawks have miles upon miles of wire for all their electronics, and even if you could turn the engine on and somehow only have their stabilization system active, they would be completely unflyable without the logic systems that keep them in flight and allow extreme manouvers. The only mechanical part is the bodywork, really.

Them hitting the RPS limit is far worse than it ever would be with a heavily loaded engine. When the engine hits its limiter, it will bounce back as much as 0.6-1 RPS(depending on engine and load), which causes catastrophic instability and jittery behavior. You can tell this by simply attaching a dial to an engine's RPS out and making it hit its cap.


The preset helicopter is unfortunately deprecated, much like the preset Eurofighter, and i do agree with you on that definitely. They were both made before engine rebalance, so now they behave in very erratic ways. I don't quite see why they're still there when they decided to remove the tutorial.

As for the shaking, i'd still love to see a video of you flying things around. I can upload my most stable helicopter as well for you to test, even though it's not something i'd commonly share, it's not really intended for public use, rather i built it for a friend of mine. I'm more just curious if you'd experience any issues with that one.