Hello everyone!
Just a “warning”, before you jump to the tutorial: this is NOT a tutorial about modelling a tank; it deals with setting the Origins and Parent-Child relationship for objects in Blender 3D to use them in a Unity Project.
Text version (and more tutorials about Blender and Unity): http://www.cg-village.com/unity-3d-game-engine-tutorials/49-blender-unity-basic-tutorial-the-tank-parenting-rotating-objects.html
Hope you like it, bye! 