Spin without input?

[Numerlor]

Why does this vehicle spin without any input? Is it because of angled wheels?

[cratercracker]

I have a theory!

The gravity of Kerbin and atmospheric drag/pressure is pushing the craft down. 

Thus creating force.

When force applied to a wheel it spins (captain obvious at his finest)

As the wheel being placed with slight angle simmetrically around the craft , the craft is moving with the direction of the wheel's spin, but there is no certain direction because of the wheels placed simmetrically around the round shaped.

This makes the craft spin.

Or it is just KSP physics phusicus

[Benjamin Kerman]

Wait, but wouldn't it just act like a suspension as there is nothing making the wheels want to spin?

[cratercracker]

3 minutes ago, Benjamin Kerman said:

Wait, but wouldn't it just act like a suspension as there is nothing making the wheels want to spin?

It partially will, but you must remember that atmospheric pressure pushing  all sides of the wheel ,maybe at one place on the wheel it makes less pressure, thus making it spin in the opposite direction of the place that takes less pressure.

And another theory-

It spins because all the wheels spin in KSP, even if you don't apply any force.

To prove my theory do this expirement:

Take "Velositiez" or whatever its called and place it on the runway.

Let one kerbal out and see how your plane is slowly sliding away from you, even if the runway is not inclined.

 

[FullMetalMachinist]

19 minutes ago, cratercracker said:

Take "Velositiez" or whatever its called and place it on the runway.

Let one kerbal out and see how your plane is slowly sliding away from you, even if the runway is not inclined.

That's a different phenomenon, and is actually accurate. The runway is perfectly flat, but it's sitting on a round planet. This makes the center of the runway very slightly closer to the center of Kerbin than the edges are. This makes it act like it has a slight 'u' shape, even though it's flat. If you give it enough time the plane will actually settle in the middle. 

[Benjamin Kerman]

Exactly that ^^^

[Numerlor]

Well that is true for wheels that are in line but wheels in circle like that shouldn't spin and if they wuold spin because of that they woulnd' always spin around their common centre

[Cunjo Carl]

Downloaded the craft to play. Only had 10 minutes, but I've confirmed it's phantom forces of some stripe between the wheels and the ground. Rocketized versions of the same performed as expected (they didn't spin uncontrollably). Setting the springs to low and dampers high on the lower two sets of wheels gave it the ability to randomly yet stably stroll around KSC, much to my delight. Making the wheel slope even closer to ground increased the phantom force, as does rotating them a bit more counterclockwise (when viewed from below). Retracting the wheels removes it completely.

Oh, and one more thing.

The Power.

It cannot be contained!!

Spoiler

 

 

The wheels do have an unusual collider that collides with the ground at this steep slope. I've never really known what it's there for, but you can see it as part of the part's green aura in the VAB.
Edit: My mistake! See @bewing below for more.

 

Good find, @Numerlor! And nice craft design  

Edited April 11, 2017 by Cunjo Carl
had a woops

[bewing]

1 hour ago, Cunjo Carl said:

The wheels do have an unusual collider that collides with the ground at this steep slope. I've never really known what it's there for, but you can see it as part of the part's green aura in the VAB.

The green aura thing is called a "lens flare". It exists to make the lightbeam from the landing lights into a directional beam. The fact that it is visible when highlighted is a small visual bug, of course. But, to the best of my understanding, the lens flare part of the landing gear does not have a collider.

And as far as your fairing test goes ... that's why the little "Extend when stowed" button exists in the landing gear context menu.

Edited April 11, 2017 by bewing

[Cunjo Carl]

10 minutes ago, bewing said:

The green aura thing is called a "lens flare". It exists to make the lightbeam from the landing lights into a directional beam. The fact that it is visible when highlighted is a small visual bug, of course. But, to the best of my understanding, the lens flare part of the landing gear does not have a collider.

And as far as your fairing test goes ... that's why the little "Extend when stowed" button exists in the landing gear context menu.

Ohhh... I remember seeing pictures of the wacky wheel colliders in 1.1 and figuring that's what the lens flare was showing. That makes a lot more sense that it's actually the light beam given it's still with us.

I've never actually seen this button... I just had a moment to check and can't seem to find it. Where is it? Sounds like a fun toy to poke at, wherever it is!

[bewing]

... That's odd. Where'd that button go? Hmmmm.