Made with Fusion 360.

A macro reverse ring for anyone interested in this kind of macro. I only made a 49mm ring, but you can comment if you want to see other sizes or you can edit the .step file by yourself. I used supports, but I guess it can be made without support as well, although I am not that sure. I printed it -180 degrees which means upside down, it is also because I printed it 3 times in a row, and only the fourth time did the print succeed. If there's any problem with the print don't hesitate to comment.

P.S I am out of filament