Benham's Illusion Top

See https://en.wikipedia.org/wiki/Benham%27s_top

I took the basic disk pattern from MosaicManufacturing's design, and merged with an "Inception" style top by Arun_H

I've liked Arun's split top design, though I struggle with tolerances around the center screw. Because of that, I shortened the screw by 1mm, tapered the ends, and softened the threads a bit.

Edit: I just added a new file "Top with Weights Resized" that has cavities designed to hold M10 hex nuts, to add weight around the perimeter. I printed in PLA (210deg) and the fit is snug. I pushed each nut in partially by hand, then pressed the top against a desktop to push it in the rest of the way. The end result spins quite well, and is very well balanced.