Ball Joint / Physics Collider Questions

New Unity user here. I've trying to build a robot character that is controlled by adding torque forces to a simple sphere rigidbody. Basically just a ball rolling around. I have that part working and controlling great but I hit a snag when trying to add additional collision geometry to this.

As the ball moves by torque/rotational forces, anything I parent to it spins around like crazy. What I want to add additional collision geometry that kind of hovers above that rolling sphere (like a head above a sphere-type-wheel) which also effects it's physics/velocity when/if it collides with something.

I've toyed around with physics joints, and what I want would be akin to a rigid body with a free-rotating 360 degree ball joint under it but I can't find one that will let the ball still rotate freely without wildly rotating and dragging the other rigid bodies behind it.

In short, is there a way to setup a joint in Unity that will let a rigidbody sphere with full 360 degree rotation act like a wheel attached to another rigid body?

 

I have the same question here in 2019. This seems like rather complex problem and the only way I found is to cheat it with complicated script using AddForce and play with physics collider settings until it looks realistic (still doesn't).

I would be happy if this question was raised higher, because it seems like Unity doesn't really have easy solution for this yet

 

just in case somebody bumps into this problem, I think what you are looking for is Character Joint
https://docs.unity3d.com/Manual/class-CharacterJoint.html