To center in blender:

• Import your stl file (created using SolidWorks)
• Use the translate menu for the object (leftmost panel on screen).
• Click translate twice, then x/y/z vector options should show up at the bottom of the menu.
• Set to whatever you want the center of the object to be, which will be the pivot when you rotate the object
• Press 'n' to bring up the cursor menu (should pop up on the right). Set x/y/z coordinates to (0,0,0) to put cursor at the pivot point you chose.
• In the object menu (left side of the screen again), click origin and set to 3D cursor location (or something like that).
• Export as wavefront (obj)
• Click include normals and set axes for forward and up