A helicopter in KSP? or How I learned to replace Firespitter

[Cranium]

Backstory: I wanted to make a helicopter. Simple, right? Let's go get Firespitter and strap on some parts from there.

Problem: Those parts don't match well. They can't really be combined in an aesthetically pleasing manner with most other parts from other mods or even stock.

Solution: Make my own propeller, with robotics and rockets.

Result: The HELO X2 (Don't worry about X1...they're experimental builds for a reason...)

It flies...okay, but is very difficult to control. Hence, the large amounts of SAS on it. It also can't go fast; and if it does, it wants to do a backflip.

Also, it tends to want to land on random things:

Craft file: http://puu.sh/9qiA8/a8ce590491.craft

EDIT: Oh, it seems I forgot to mention the mods used. Currently, just MechJeb, Infernal Robotics, and FAR. Yes, that's right. This craft is compatible with FAR, and it was surprisingly easy. Check out this video to see the X1 on its maiden flight.

Edited June 12, 2014 by Cranium
better title, IMO

[dryer_lint]

Whoa. That's pretty cool.

[Cranium]

Whoa. That's pretty cool.

I'm glad you like it!

I plan on making a twin rotor design next, for heavy lifting. Maybe I can get it to the island airstrip this time!

[Blue]

Helicopters usually (read: almost always) have an even number of rotor blades, because this ensures each rotation of the rotor set has an even amount of lift vs loss of lift from the advancing side and retreating side. This is called Retreating Blade Stall.

[Rune]

Helicopters usually (read: almost always) have an even number of rotor blades, because this ensures each rotation of the rotor set has an even amount of lift vs loss of lift from the advancing side and retreating side. This is called Retreating Blade Stall.

http://www.copters.com/aero/pictures/Fig_2-86.gif

That has nothing to do with the number of blades and everything with the horizontal speed of the chopper: each blade "sees" a faster wind when it is going forwards than backwards. All modern helicopters with one rotor are kind of restricted to <400kph speeds, more or less, before they want to flip more than they can compensate, regardless of T/W. In fact, there are lots of russian helicopter with five blades (the hind, to cite a famous one) that fly perfectly, and their high speed by western standards is due to the stubby wings they hang missiles from, those actually compensate said effect somewhat.

Rune. But the graphic is spot on.

[Sparker]

Very cool. I like that chopper.

Usually on helicopters your main control is angle of attack of the blades, but not RPM of the rotor, it stays more or less stable. It would be good to write a KOS script that would monitor rotor RPM(if it's possible to get such information) and adjust trust to stabilise it, while you would change AOA of the blades as you need.

[Cranium]

I would love to get rid of the rocket engines on the blade tips, because with that, it's incredibly hard to sustain a long flight, since I run out of fuel so quickly. I'd like to swap out the free washer, and use the IR moving washer, but for some reason, I can't set speeds or keybindings to them. I wish there was some sort of useful tutorial for that.

What I'd REALLY love, is to be able to set some sort of toggle on/off for the blades, and just adjust the speed and feathering as necessary.

Edited June 13, 2014 by Cranium

[Nephf]

Come on, bring it to orbit

[ThirdHorseman]

I would love to get rid of the rocket engines on the blade tips, because with that, it's incredibly hard to sustain a long flight, since I run out of fuel so quickly. I'd like to swap out the free washer, and use the IR moving washer, but for some reason, I can't set speeds or keybindings to them. I wish there was some sort of useful tutorial for that.

What I'd REALLY love, is to be able to set some sort of toggle on/off for the blades, and just adjust the speed and feathering as necessary.

I remember reading something on the MSI-IR thread that you can assign an action group to the "move" function of a washer or rotatron, and that will toggle the motion on and it will run continuously. You can then just enter the speed in the text field in the GUI to control speed.

Or you could switch to jet engines...that way your fuel will last much longer.

EDIT: Here is the post

Edited June 13, 2014 by ThirdHorseman
added link to thread

[Cranium]

I remember reading something on the MSI-IR thread that you can assign an action group to the "move" function of a washer or rotatron, and that will toggle the motion on and it will run continuously. You can then just enter the speed in the text field in the GUI to control speed.

Or you could switch to jet engines...that way your fuel will last much longer.

EDIT: Here is the post

Ah, cheers, man. That's going on the next versions then.

[Sparker]

You can also try adding control surfaces as flaps to your plades, you'll have about 3 or 4 fixed positions for them. Also, try simply adding control surfaces to your blades. Maybe they will behave like cyclic control on real helicopter!

[Cranium]

Well, there's already control surfaces on the blades. Unfortunately, they spin too fast for them to be of much use. I'm going to try out the action groups tonight, and I'll see what I can do with that. It sounds exactly like what I need for this project.

[Cranium]

YAY! I got another prototype working! I now also have what I now realize as a Cupcake-esque video.

Using what I learned from previous attempts, I made a quadrocopter! It's actually quite nice to fly, and easy to handle (If you don't go too fast, that is...).

Give it a try!

http://puu.sh/9w697/3160ff898b.craft

[xtremespino]

Wow, awesome design, its great to see that it actually handles properly, and doesn't just go straight up and down.

[Cranium]

If I could be bothered, I could use action groups, and have the rotors feather their blades individually, so that you don't have to rely on SAS to control the craft, you could actually use proper lift just like a real quadricopter does.