Helicopter Design

[Praetorian]

Hello there, 

I decided it was time to start building some helicopters, and I quickly found it harder than building a fixed-wing aircraft. So my question is, does anyone have any design tips and/or guides on how to build Helicopters.

I am using FAR, KAX, KXR to name a few and i head that TCA was a good addition for Helicopters.

 

thanks in advance!

[Signo]

I know you listed a few mods, but since there is no IR in the list I will go on assuming you need to engineer your own hinges.

There are pretty good stock choppers around, but they are pretty "demanding" from a game perspective - since you miss stock hinges you need to BYO, therefore increasing the number of parts. Last stock chopper I downloaded was above 200 parts. 

Moreover if you do not use a "turboprop" (and here we need to summon @Azimech for a proper explanation) performances range from lame to useless in terms of gameplay. 

If, by any chance, you did not mean to build a "propeller chopper" but something more like a dropship XCOM style, this one is a wonderful example and a stock engineering masterpiece.

 

[Azimech]

Helicopters are made in various ways. From very light and low part count to extremely heavy and high part count. Usually my 'copters are in the last category.

Here's my only mod helicopter, using Firespitter and BDA. Don't know if it will run in 1.1.3/1.2, haven't touched it in a while.

https://kerbalx.com/Azimech/77I--Mil-Mi-24-Hind-D

Here are three stock helicopters. They use stock turboshaft engines. The first two are are heavy but feature a relatively low part count:
https://kerbalx.com/Azimech/77I--Azi16-Abraxas-v1

https://kerbalx.com/Azimech/77I-Azi15-Archon

This one is heavy and has a high part count.

https://kerbalx.com/Azimech/77I-Azi14-Asura-v11

All my stock helicopters are easy to fly but because we don't have mechanical features like cyclic/collective they have a low top speed. I suggest you analyze their construction, fly around with them and try to replicate how they're done. If you still have questions, send me a message. After building/flying stock 'copters, the modded ones are easy as pie. Good luck and have fun!

[capi3101]

Going to link you to a very old guide here for how to build transporter spaceplanes back in 0.24. Why, you may ask? Because there's a section in there in what it takes to build a working VTOL craft, and while the particulars have changed a great deal in the time since that guide was written, the general principals haven't. Also includes suggestions for how to go about testing them.

I'd strongly suggest that, if it's not there already, you add RCS Build Aid to your VTOL toolkit. When it comes to any VTOL craft, having a center of mass that doesn't shift around a whole lot in flight is an essential part of the design, and RCS Build Aid can give you that information.

[surge]

The hardest thing about helicopters is building a bearing. Ive never heard of 1/2 of the mods you mention, but Infernal Robotics is the only one I know of that has one.

You can build stock bearings, but they are far too fragile to withstand the forces a real helicopter rotor hub needs. That is why all attempts so far have been essentially just 'things that whirl fixed blades around' like the early helicopters humans used to try to make. They used to be nicknamed whirlybirds, unsurprisingly, and all crashed spectacularly until Igor Sikorsky decided to incorporate a swashplate with a tail rotor.

Unfortunately, no one can describe how a swashplate works. You just have to see it.

Thus, the key to stable helicopters is the ability to change the angle of attack as the blade rotates, and longditudinal blade flex. Stock KSP doesnt have materials that are stiff in one direction but sloppy in another like a rotor blade. Nor the ability to make bearings small enough required for them. Even if you used something like Tweakscale and IR to make the tiny blade bearings, the game doesnt calculate physics fast enough - the swashplates, if not the actuators would almost immediately be destroyed.

Makes you think, doesn't it - these little green b.astards have figured out explosives well enough to take them to other worlds, yet they cant even figure out how to make a simple mechanical device.

Edited September 14, 2016 by surge

[Azimech]

2 hours ago, surge said:

 

You can build stock bearings, but they are far too fragile to withstand the forces a real helicopter rotor hub needs. That is why all attempts so far have been essentially just 'things that whirl fixed blades around' like the early helicopters humans used to try to make.

 

Ahem. 73 tons. 100% stock. Even works in 1.2 pre-release.

 

[surge]

Congrats. You made a thing that looks like a helicopter. How many billions of sas units does it need.

 

[Azimech]

2 minutes ago, surge said:

Congrats. You made a thing that looks like a helicopter. How many billions of sas units does it need.

 

You're free to count them yourself.

[Azimech]

1 hour ago, surge said:

Congrats. You made a thing that looks like a helicopter. How many billions of sas units does it need.

 

And I'd like to see what kind of "thing" you can come up with. Come on, impress me.

[Kenny Kerman]

13 parts (including 4 floats and 2 "useless" wings) 11 seats "Huey" :

 

Edited May 11, 2017 by Kenny Kerman

[ARS]

Some advice and help about building and flying helicopter in KSP that I've given to @jackstech in the past. Hope this helps:

 

[Azimech]

Protoype helicopter with a swashplate: https://kerbalx.com/JimmyR/Swashplate-Prototype-02