Draw a torus on every face of a cube. The tori meet along the edges of the cube. Clamp these joints with a smalled turus perpendicular to the edge of the cube.

Method 1:

Determine the place and orientation of the tori one by one, then combine the tori.
 
 

Method 2:

Draw two tori. Construct a module which can be regared as one face of the cube, and produce the faces of the cube.