OK Last work of the year. I always try to make at least 10 works a year and I barely made it this year. I made some fairly ambitious pieces that required I put in a lot of extra time so here we are just in time.
This one was designed around a turnbuckle system, where in each of the spheres is designated as a right hand or left hand sphere that is then joined together by a bronze bushing (the center pieces) that drives a brass turnbuckle style bolt. (see Detail drawing below)
Below is two assembly pictures for a real world look at how it is assembled (notice the square holes in the Bronze bushings, those mate with the square bolt centers you see in a pile between them, that is how they are able to be driven by turning the bushings)
As you can see once the top four are drawn together then each of the top and bottom quads are drawn together into the final cube. (below)