I have the main rails tied together at the front and back spaced at 6½" with 5/16" bolts and ½" PVC pipe.
I think I have my side supports figured out by using 5/16" thread-all tensioned with ½" PVC pipe as the arms secured with a washer and nut.
A quick snapshot of the uncut thread-all ready to be sized up...
The lazy Susan belly pan will consist of a single layer of Coroplast ziptied to the support structure which should be able to provide enough rigidity to the belly pan.
I will have to find something to provide the outer enclosure to the lazy Susan belly pan. Maybe a 36" diameter metal ring...maybe from an industrial/commercial HVAC system. I could also build it from some gutter guard and cover that with something.