Is it possible to create a solar-powered aircraft in stock KSP?

[Grant Exploit]

After learning how to make propellers in stock KSP, I wondered if it was possible to make a solar-powered aircraft, like Solar Impulse or the NASA Helios. The problem is, all the propeller engine designs I've seen require the engine to be physically separate from the aircraft, preventing electricity from wing-mounted solar panels from reaching it. Is it possible to make a propeller engine that isn't physically separated from the aircraft, or somehow "beam" electricity into the engine? If not, are there any easy code fixes that can allow either of those things? 

[vyznev]

Put the solar panels on the propeller blades?

[Dimas152]

why not use ion thrusters instead? u can change the thrust limiter into 1000 by editing the .craft file via notepad
 

Spoiler

btw why don't you put this on general KSP discussion

 

[GillyMonster]

3 hours ago, [INDO]dimas_1502 said:

why not use ion thrusters instead? u can change the thrust limiter into 1000 by editing the .craft file via notepad
 

 

But then its not stock...

[Dimas152]

51 minutes ago, GillyMonster said:

But then its not stock...

nope it's still classified as stock
 

[sevenperforce]

6 hours ago, [INDO]dimas_1502 said:

nope it's still classified as stock
 

Nope.

[Grant Exploit]

10 hours ago, [INDO]dimas_1502 said:

why not use ion thrusters instead? u can change the thrust limiter into 1000 by editing the .craft file via notepad
 

  Hide contents

btw why don't you put this on general KSP discussion

 

Ion thrusters still require propellant. And I don't know how to move topics to different subforums.

[sevenperforce]

Put the panels on the props themselves, if you can. Otherwise no, not really.

[Dimas152]

5 hours ago, Grant Exploit said:

And I don't know how to move topics to different subforums.

ask moderator

[linuxgurugamer]

5 hours ago, Grant Exploit said:

Ion thrusters still require propellant. And I don't know how to move topics to different subforums.

Easiest way is to ask a moderator via the report post link

[vyznev]

Anyway, a bit more seriously, I see at least three possible ways to attempt this, each with their own advantages and drawbacks:

1. Put the solar panels on the engines, as suggested above. Probably not very practical for giant panels and high-power engines, but a couple of small OX-STAT panels on the propeller blades or on the hub should be able to power a single reaction wheel.
    
2. You could periodically stop the engines and reattach them to the main craft (with docking ports or a Klaw) to transfer power. With enough engines on your plane, you could even safely do that one engine at a time while using the rest to maintain your speed. The main downside is that this would require a lot of manual micromanagement, unless you used something like KOS to automate it.
    
3. There's an alternative stock rotor design that uses rover (or plane) wheels on the main vessel to power the rotor. Here's a couple of examples from an old thread. These do seem to have some reliability issues with the wheels glitching and/or popping, but if you could solve them, they might be ideal for your purposes.
   
   I'm not sure how to best control the drive wheels on a plane, though, with the rotor axis presumably pointing lengthwise. I guess you could try mounting the wheels at, say, a 45 degree angle to the propeller axis and just driving forward/back (remember to bind those to some other keys than the default W/S, or you'll have a nasty surprise) to spin the propellers. Or if you used just one powered wheel per rotor and left the rest unpowered, you might be able to use the translate up/left/down/right controls (I/J/K/L by default) to make them spin. This may require some experimental work.

[sevenperforce]

2 hours ago, vyznev said:

1. There's an alternative stock rotor design that uses rover (or plane) wheels on the main vessel to power the rotor. Here's a couple of examples from an old thread. These do seem to have some reliability issues with the wheels glitching and/or popping, but if you could solve them, they might be ideal for your purposes.
   
   I'm not sure how to best control the drive wheels on a plane, though, with the rotor axis presumably pointing lengthwise. I guess you could try mounting the wheels at, say, a 45 degree angle to the propeller axis and just driving forward/back (remember to bind those to some other keys than the default W/S, or you'll have a nasty surprise) to spin the propellers. Or if you used just one powered wheel per rotor and left the rest unpowered, you might be able to use the translate up/left/down/right controls (I/J/K/L by default) to make them spin. This may require some experimental work.

Yeah, this is a promising solution. It's easy enough to set individual wheel motor direction.

[sevenperforce]

Okay, I toyed around with this a little bit today.

Basic bearing inside the fairing (no fairing-bearing interaction), a nose cone, some props. I've verified that the bearing design works using the standard probe-and-wheel approach. The little monoprop tank was placed on the nose cone and offset back. The wheels are all attached to the second cubic strut and attached one-by-one, so I can set wheel direction on each, but the group of six struts can be used to move them all in unison.

So far, I'm having trouble getting good purchase on the monoprop tank with the wheels. I tried going up a wheel size but it had no effect whatsoever. Playing around with the spring, damper, and traction settings has gotten me to the point that I can controllably rotate the tank (and thus the propshaft), but RPM is far too low for any aero effects.

[Pds314]

Yes, but quite difficult. Here's the complete list of mechanisms which can be solar-powered with no other resources:

Wheels.

SAS torque.

Drills rumbling while in use.

Now, there are a few other mechanisms which need only control of the craft to run:

Ladders extending.

Landing gears extending.

Lander legs extending.

Drills extending.

Control surfaces moving.

Engines gimbling.

The power of the space Kraken.

The Claw.

Auto-strut abuse.

Most of these are either too hard to harness, too fragile, or too slow to be of any use.

That being said, SAS can be used, at least with enough solar panels on the propeller assembly.

And anyone brave or foolish enough to attempt an ornithopter can use landing legs, possibly the drill, possibly ladders, and definitely aircraft control surfaces to flap larger and powerful wings.

[vyznev]

11 hours ago, sevenperforce said:

So far, I'm having trouble getting good purchase on the monoprop tank with the wheels. I tried going up a wheel size but it had no effect whatsoever. Playing around with the spring, damper, and traction settings has gotten me to the point that I can controllably rotate the tank (and thus the propshaft), but RPM is far too low for any aero effects.

Hmm, what about replacing the tank with a linear RCS port? A smaller radius should give a higher rotor RPM for the same wheel speed. You might need to reduce the number of drive wheels to make them fit, but that should be OK as long as the shaft is reasonably solidly built. I'd also try the TR-2L wheels, and maybe plane landing gear.

(I may have to install KSP on this laptop just to give this a try myself.)

[sevenperforce]

2 hours ago, vyznev said:

Hmm, what about replacing the tank with a linear RCS port? A smaller radius should give a higher rotor RPM for the same wheel speed. You might need to reduce the number of drive wheels to make them fit, but that should be OK as long as the shaft is reasonably solidly built. I'd also try the TR-2L wheels, and maybe plane landing gear.

(I may have to install KSP on this laptop just to give this a try myself.)

Plane landing gear is unpowered so it won't do any good.

The main problem is that there is just a tiny amount of wobble in my axle bearing, and so the drive wheels end up pushing the monoprop tank in a circle, since they are springy. For this to work, my axle really needs to be rock-solid.

Rebuilding it with the drivetrain in the center of the axle, rather than at the end, may help. Ideally you would end up with a subassembly that you could simply drop under any airplane wing in pairs...

[sevenperforce]

All right, I did a little redesign and I'm pretty pleased with where things are so far.

As you can see, I've gotten it up to the whopping taxi speed of 10.3 m/s. Impressive, I know. I may test it using octagonal struts instead of the monoprop tanks, as they may provide slightly better purchase for the drive wheels. I guess if I try it out and it gets a higher taxi speed, I'll have my answer!

Next step will be to wrap this contraption in a fairing, put some VERY large wings on it, and see if I can get it off the ground.

[sevenperforce]

EDIT: The octagonal struts were definitely an improvement. 

[sevenperforce]

Slowly making improvements:

Nowhere near fast enough for takeoff, but hey, small steps.

 

[EpicSpaceTroll139]

It's been a while, but I recall it being fairly easy (assuming you've mastered basic electric props first) to make solar powered stock props by placing the solar panels on drum that spins around the outside of the bearing and reaction wheel housing. Will find some pictures when I get the chance.

[Tetragon213]

Back in the olden days, the Ion Engines were somewhat useable in atmospheres. Hence the old "GreenPower Challenge" (The only signature I've ever achieved; I'm terrible at this game lol!)