[Stock Helicopters & Turboprops] Non DLC Will Always Be More Fun!

[EpicSpaceTroll139]

I've been working on my own heavy-lift helicopter, and I accidentally discovered an effect that helps significantly with the problem of dissymmetry of lift, while ironically being caused by it.

As I make the blades longer to help absorb more power (in this case 4 panthers), they are able to flex, riding upward as they get more lift and down as they get less. This greatly increases the speed I can go without rolling over compared to my smaller helis (even taking away the wings with the ailerons). However gyroscopic effects cause the blades to ride up in the forward region and down in the aft region, so some of the rotor lift is directed backwards, working against my forward speed. I need to do some testing to determine if this is enough to warrant using a tandem rigid rotor design instead.

Also been working slowly on a preliminary base for a cyclic code. I now have a vague idea of how to translate pilot inputs into rotor flap movements. I have no idea how to give SAS any control in the matter though.

Edited January 26, 2017 by EpicSpaceTroll139

[Gman_builder]

@klond Your new little heli is definitely a sight to behold!!! You make the coolest stuff in this game i swear!

[Azimech]

1 hour ago, EpicSpaceTroll139 said:

I've been working on my own heavy-lift helicopter, and I accidentally discovered an effect that helps significantly with the problem of dissymmetry of lift, while ironically being caused by it.

As I make the blades longer to help absorb more power (in this case 4 panthers), they are able to flex, riding upward as they get more lift and down as they get less. This greatly increases the speed I can go without rolling over compared to my smaller helis (even taking away the wings with the ailerons). However gyroscopic effects cause the blades to ride up in the forward region and down in the aft region, so some of the rotor lift is directed backwards, working against my forward speed. I need to do some testing to determine if this is enough to warrant using a tandem rigid rotor design instead.

Also been working slowly on a preliminary base for a cyclic code. I now have a vague idea of how to translate pilot inputs into rotor flap movements. I have no idea how to give SAS any control in the matter though.

Yeah I noticed this as well. You'll probably like my manual when it's finished. And ... nice evolution of my hull design! It's really looking good!

Cyclic code, you mean writing a plugin? That's very cool!

[_Rade]

33 minutes ago, Azimech said:

Cyclic code, you mean writing a plugin? That's very cool!

I'm guessing he means being able to tilt the whole rotor around, the way the real helicopters do it.

Few weeks back I've made this ugly contraption. You can tilt the rotors but the damn thing is nearly impossible to fly or control. The way this works, there is a single stayputnik inside the the fairing and below it there is small LF tank attached to it. There is also 4 elevons around it so when you pitch or yaw the elevons push the fuel tank around and this causes the rotor to tilt in the direction you want to move.

After seeing the post by the @EpicSpaceTroll139 I've tried replacing the fairing with the structural fuselage to see if that will help. But there is almost no difference. Problem seems to be caused by the SAS acting up on the elevons and the vibrations from the fuel tank colliding with the elevons.

 

Spoiler

 

updated version

 

 

[Azimech]

11 minutes ago, _Rade said:

I'm guessing he means being able to tilt the whole rotor around, the way the real helicopters do it.

Few weeks back I've made this ugly contraption. You can tilt the rotors but the damn thing is nearly impossible to fly or control. The way this works, there is a single stayputnik inside the the fairing and below it there is small LF tank attached to it. There is also 4 elevons around it so when you pitch or yaw the elevons push the fuel tank around and this causes the rotor to tilt in the direction you want to move.

After seeing the post by the @EpicSpaceTroll139 I've tried replacing the fairing with the structural fuselage to see if that will help. But there is almost no difference. Problem seems to be caused by the SAS acting up on the elevons and the vibrations from the fuel tank colliding with the elevons.

 

  Hide contents

 

updated version

 

 

 

Reminds me of my own experiments ... I used a more conventional setup. Now that we have new landing gear code I might give it a try again.

You've done great even if it doesn't work right now. I've noticed you're making them both pivot ... Did you try it in a single rotor setup?

What exactly is happening when you fly it?

[_Rade]

Twitchy SAS moving the elevons trying to maintain the stability. This causes the heli to pitch up or down or roll and after that it is almost impossible to recover it.

While it is level the yaw works fine and you can turn the heli just using the rotor tilt.

One thing I didn't try is to disable the pitch and yaw on elevons and to deploy them with action groups, but that would make flying this even bigger challenge.

Here is the craft file if you want to try it https://kerbalx.com/Rade/Copter

[EpicSpaceTroll139]

16 hours ago, Azimech said:

Yeah I noticed this as well. You'll probably like my manual when it's finished. And ... nice evolution of my hull design! It's really looking good!

Cyclic code, you mean writing a plugin? That's very cool!

Thanks! It is indeed based off of yours, although I first tried other fuselage designs and then came to the conclusion that yours was the best for getting a somewhat rounded look with a flat floor.

As for code I meant a script for K-OS. Creating a new plugin is way out of my league haha.

Edit: Progress on the heavy-lift

Edited January 26, 2017 by EpicSpaceTroll139
Progress

[The Optimist]

Fairing engines: Exceedingly light, and efficient, but highly unstable.

[_Rade]

@The Optimist what kind of issues are you having with the fairings I might be able help with that.

[The Optimist]

4 minutes ago, _Rade said:

@The Optimist what kind of issues are you having with the fairings I might be able help with that.

As a result of asymmetrical life and natural precession, the blades themselves start to tilt inwards. The fairing remains straight. And the engine pictured is my own extra-long variant, which is far more stable than the smaller plane engines I normally use.

[Gman_builder]

17 hours ago, _Rade said:

I'm guessing he means being able to tilt the whole rotor around, the way the real helicopters do it.
 

  Reveal hidden contents

 

updated version

 

 

real helicopter dont tilt the whole rotor. They adjust the angle of individual blades.

[_Rade]

37 minutes ago, The Optimist said:

As a result of asymmetrical life and natural precession, the blades themselves start to tilt inwards. The fairing remains straight. And the engine pictured is my own extra-long variant, which is far more stable than the smaller plane engines I normally use.

Other than that heli in the post above, I've been using the fairings to build plane propellers, and propeller blades usually don't bend. Other than autostruting the blades to the root part inside the rotor I'm not sure what else you can do about it.

On the propellers I use, usually there is long or short I-beam as the root part and 2 or more stayputniks acting as the bearings. Also on the front of the propeller there is small docking port which sort of acts as the buffer or a spring and the front stayputnik is pushing against it. Otherwise if the front stayputnik is pushing on the part on which the faring is closed that can cause the vibrations in the faring which in turn usually transfer to the rotor.

 

@Gman_builder I know, but effectively the end result is more or less the same.

[Gman_builder]

17 hours ago, _Rade said:

 

@Gman_builder I know, but effectively the end result is more or less the same.

Uh. Ok.

[EpicSpaceTroll139]

@_Rade @Gman_builder Both of you are right actually. 

The control is called the cyclic because it changes the pitch of the rotor blades cyclically. The result is to tilt the rotor disk in a particular direction, resulting in the helicopter moving in that direction.  

-Wikipedia

[Gman_builder]

15 hours ago, EpicSpaceTroll139 said:

@_Rade @Gman_builder Both of you are right actually. 

The control is called the cyclic because it changes the pitch of the rotor blades cyclically. The result is to tilt the rotor disk in a particular direction, resulting in the helicopter moving in that direction.  

-Wikipedia

I know. The rotor disk is what is produced when the blades start spinning. So tilting the blades tilts the disk.

Edited January 27, 2017 by Gman_builder

[klond]

12 hours ago, EpicSpaceTroll139 said:

The control is called the cyclic because it changes the pitch of the rotor blades cyclically.

 I been on google image search looking at every rotor head? (still working on all the terminology) I can find.  I'm going mock up a sample soon.  The goal is

-2 blades that can rotate on their own axis

-a slow turning reaction wheel motor to spin the rotor head for demonstration

-a cockeyed plate for the linkages to slide up and down on as they go round. 

-an engine stand for the whole thing

 You guys might have done all this already, but I'm gonna give it a try too.  I think this is a small enough goal to have success, then we can work on making the plate (terminology, can't look it up right now) movable later.  I don't promise anything because I get distracted - there's so much stuff yet to make (damn you, stock weapons thread).

[EpicSpaceTroll139]

3 hours ago, klond said:

<snip>

 You guys might have done all this already, but I'm gonna give it a try too.  I think this is a small enough goal to have success, then we can work on making the plate (terminology, can't look it up right now) movable later.  I don't promise anything because I get distracted - there's so much stuff yet to make (damn you, stock weapons thread).

Good luck. I've looked back through all my contraptions and this was the most "successful" (more like least bad) rotor head I made.

It only has cyclic because giving it a true collective would mean I would have to separate the blades into 2 units instead of having them as one beam, thus pretty much guaranteeing they would come flying out due to centrifugal forces. Even though I put effort into making sure the COM of each component was on the axis of rotation, it only survives for a little while at around 15rpm, without having been moved from neutral position.

It's also missing the important teeter hinge to allow the blades to fly up and down as lift distribution changes. However I'm worried that would also result in the blade separation problem I mentioned earlier

Edited January 27, 2017 by EpicSpaceTroll139

[Majorjim!]

4 hours ago, EpicSpaceTroll139 said:

Good luck. I've looked back through all my contraptions and this was the most "successful" (more like least bad) rotor head I made.

It only has cyclic because giving it a true collective would mean I would have to separate the blades into 2 units instead of having them as one beam, thus pretty much guaranteeing they would come flying out due to centrifugal forces. Even though I put effort into making sure the COM of each component was on the axis of rotation, it only survives for a little while at around 15rpm, without having been moved from neutral position.

It's also missing the important teeter hinge to allow the blades to fly up and down as lift distribution changes. However I'm worried that would also result in the blade separation problem I mentioned earlier

Is that a different version of the one you sent me to have a look at? I still have it in one of my saves somewhere.

[EpicSpaceTroll139]

1 hour ago, Majorjim! said:

Is that a different version of the one you sent me to have a look at? I still have it in one of my saves somewhere.

I think it might have some slight modifications (not sure), but nothing that made it work better or even differently.

[Majorjim!]

4 minutes ago, EpicSpaceTroll139 said:

I think it might have some slight modifications (not sure), but nothing that made it work better or even differently.

It looks quite different. Sad that it isn't reliable, it's a lovely design.

[EpicSpaceTroll139]

Just now, Majorjim! said:

It looks quite different. Sad that it isn't reliable, it's a lovely design.

Oh it might be that I added those control surfaces on the short ibeams to demonstrate how it would be moved... if it worked... Unfortunately it does not

[Majorjim!]

19 minutes ago, EpicSpaceTroll139 said:

Oh it might be that I added those control surfaces on the short ibeams to demonstrate how it would be moved... if it worked... Unfortunately it does not

No it had ibeams in an inside down triangle position that part of it rested on. I fiddled with it, and got it working  but it was very unreliable.. :-(

[klond]

 I got treat for you guys.

 Can you see each blade tilting on this microscopic gif?

 The head is huge, but the one medium reaction wheel can't break it (this was about max speed).  This is mostly what I was imagining.  The um cyclic control circle thing isn't movable, it's just a demo.  I like that the clamps for each blade look realistic somewhat.  I'm happy with it so far.

Edited January 28, 2017 by klond

[Deizelpunk]

On 1/27/2017 at 9:46 PM, klond said:

 I got treat for you guys.

Can you see each blade tilting on this microscopic gif?  The head is huge, but the one medium reaction wheel can't break it (this was about max speed).  This is mostly what I was imagining.  The um cyclic control circle thing isn't movable, it's just a demo.  I like that the clamps for each blade look realistic somewhat.  I'm happy with it so far.

Very cool!

Edited January 29, 2017 by Deizelpunk

[EpicSpaceTroll139]

12 minutes ago, klond said:

 I got treat for you

<Snip>

 The head is huge, but the one medium reaction wheel can't break it (this was about max speed).  This is mostly what I was imagining.  The um cyclic control circle thing isn't movable, it's just a demo.  I like that the clamps for each blade look realistic somewhat.  I'm happy with it so far.

Nice! I'd been thinking about trying out your thermo rcs bearing for this kinda thing. I wonder what would happen if you attached a turboshaft motor to it.

On a side note, perhaps mine would work as well if I didn't put a probe core on every single component. I got in the habit of doing that because debris typically gets autodeleted on DMP servers