He looks pretty good, why not stop with a static droid?

Oops!

After my last testing, someone more rational than I suggested "he looks pretty good, why not stop with a static droid?" or maybe I "like the mess."

Being less balanced myself, I confess I found myself somewhat at a loss to how to respond to that remark 

I guess it's kind of like climbing Everest. I'm at base camp and I'd really like to get to the summit. It may prove impossible (more impossible?) but I've made it this far, so I have to try...

(FWIW, the mess isn't as bad as it looks, "only" 3 of the panels fell off (ok, half the sphere), but the panels stayed mostly intact and it took 20 minutes or so to reassemble.)

For those questioning my sanity, this isn't even the hard part.  I'm not at all concerned that I'll be able to get the sphere to roll.

The first roll test showed that the sphere is "round enough" (& stable enough when it gets Kragle'd).

This second test, short though it was, demonstrated that an axle centered on the triangles should be aesthetically pleasing.  Three panels fell apart, but without most of the internal structure expected to support the final model that isn't surprising. (He needs more 3D printed panels, and, of course, the Kragle!)

Where I'm afraid the obstacles may become insurmountable is getting the head to smoothly slide over the dome.  THAT's going to be the hard part!

I have a fallback plan to make him approachable even if that fails.  I also suspect that even if the rolling ball works, he's likely going to be limited by terrain and in speed.  L3-G0 placed 3rd in a race, I don't think Lego BB-8 is going to do that!