Sat, Mar 20, 2021 at 8:07 AM
Attached is a sketch of another approach, based on the earlier one I sent. It's simpler over all, and proposes a "blade-like" central shaft. I believe, when the boxes are all loaded up, this blade would be more than adequate for the job, strength-wise. But, I'm no structural engineer, and certainly no artist: anything you think works and looks best would be just fine.