How do I change the center of an object for correct rotation?

Question

I have a 3D object that I exported from blender:

Then I load it into a unity and get a center like this:

Answer 1

On the top of Unity there are two pivot modes

• Center automatically uses the "Center of geometry"
• Pivot is the actual pivot point of the 3D model

Make sure it says Pivot.

See also Unity Manual - Positioning GameObjects