Pictured below are my part and an O-Ring I'm trying to mate.

The cyan surface is a spherical radius, the green surface is a groove cut into the spherical radius, the black part is just a standard o-ring.

I was hoping to select the green surface and the outer surface of the o-ring, apply a tangent mate and move on.

The diameter of the o-ring is sized so that it would be centered in the groove if the tangent mate worked.

However this doesn't work so I'm looking for advise on how how to accomplish this mate.

I can create a plane on the outside of the o-ring that is angled to correspond with the groove and use that with the tangent mate.

I have a multitude of configurations and the groove angle changes with each one, so before I went that route I thought I'd ask if there is a better way to do this.

Thanks in advance for any ideas.