Biplane Cannot Turn or Barrel

[SophiaMakoto]

Hello, I'm trying to recreate some real-life aircrafts in KSP, and I'm having an odd problem: my biplane won't turn and barrels extremely slowly. Here's what it looks like:

Spoiler

Everything else appears to work fine, it can tilt up and down, and such. It's just that the back fin appears to not work. When I am turning on the ground, the controls are reversed as well, though that's not my main issue.

I'm new to this forum, so I apologize if this is in the wrong place.

[Snark]

Welcome to the forums!  You're totally in the right place. 

A couple of things:

• First, disable roll authority on your tailfin-- right-click on it, you want it to be doing nothing but yaw.  This will help your stability and make it more effective at yawing.
• You're slow to roll because the elevators on the tail don't have much torque-- they're close to the center axis of the ship.  Try putting some ailerons out on the wingtips, it'll give you lots of roll authority.

[FullMetalMachinist]

10 minutes ago, Snark said:

A couple of things:

• First, disable roll authority on your tailfin-- right-click on it, you want it to be doing nothing but yaw.  This will help your stability and make it more effective at yawing.
• You're slow to roll because the elevators on the tail don't have much torque-- they're close to the center axis of the ship.  Try putting some ailerons out on the wingtips, it'll give you lots of roll authority.

To add to this, also try disabling the roll on your back elevators (horizontal controls on the back). You generally want those to only be responsible for pitch (up/down).

49 minutes ago, SophiaMakoto said:

When I am turning on the ground, the controls are reversed as well

Which controls are reversed? Can't see from your screenshot (I can only see the small fixed gear at the back), but do you have the small, steerable landing gear on the front? If that's what is steering the wrong way, then you can right click on the gear and choose "reverse steering" to get them going in the right direction. If that's not the problem, then I'm not sure what to do, but another screenshot of the underside will help diagnose.

[pincushionman]

As Snark said, you need ailerons - any control surface will do, attached to your wings. Set to roll only. Start with just two; otherwise you may end up with more roll authority than you know what to do with.

Set horizontal tail to pitch only, vertical tail to yaw only. And disable torque in the command pod. If you think you need it then you don't have enough control surface.

[Rocket In My Pocket]

Spoiler

A traditional plane has 3 sets of control surfaces for controlling it's 3 possible directions of movement. Your plane is missing a set. Nice looking biplane by the way!

[Vanamonde]

I made a quite similar plane. 

 

Note: it still rolls like a slug despite having 6 aeulerunspellables. I think it's the big slab wings wanting to just keep flying level. 

[Melfice]

49 minutes ago, Vanamonde said:

I made a quite similar plane. 

[snip]

Note: it still rolls like a slug despite having 6 aeulerunspellables. I think it's the big slab wings wanting to just keep flying level. 

It might have to do with the wingtips being at an angle to the rest of the wing.
Being dihedral creates stability. Normally it should translate yawing motion into rolling motion, but who knows in KSP.

I'll bet you 5 fake-bucks that removing the wingtips would fix your stability "issue".

[pincushionman]

1 hour ago, Vanamonde said:

I made a quite similar plane. 

 

Note: it still rolls like a slug despite having 6 aeulerunspellables. I think it's the big slab wings wanting to just keep flying level. 

I guess there's a whole lot of pendulum effect going on too, which I didn't think about.

EDIT. It doesn't help that aero forces are applied at the wing root, not at any kind of center. It's why dihedral doesn't really help much unless you use multiple wing sections. The moment arm is too short. Where are elevons' forces applied?

Edited March 15, 2016 by pincushionman

[fourfa]

I made one of these last night, great fun! 

[SophiaMakoto]

Thank you all for the suggestions. The problem has been solved, and it was actually because the Remote Guidance Unit was facing up and not forward. The roll is now faster by adding Elevon 1s on the outer back parts of the wings. The steering is still acting weird though, and it's not just on the ground. I think the issue is that the only way to steer is in the back, with the one wheel and fin. Reversing worked for the wheel, but I'm not sure how to do it for the fin.

Picture below:

Spoiler

 

Edited March 16, 2016 by SophiaMakoto

[FullMetalMachinist]

OK, I couldn't resist, I had to join the fun. I present, The BarnStormer! 

Spoiler

 

I had the same "slow roll" issues as @SophiaMakoto, and my solution was Moar Control!  I went a little overboard and added the (comparatively) huge BigS Elevon 2's to the wingtips. The result was quite fun to fly around. I had a little mishap on the first landing attempt, but thank's to the BigS parts, I had enough control to spare, and made a safe landing.