This is a design that I modeled in Tinkercad. What is unique about this is that I designed it so that after you print it, if you are careful enough then you can pry the tube around the ring up and off and it will be permanently locked around the middle pole.
This was my first ever print on my first 3D printer so I didn't exactly have it fine tuned but I think it still came out pretty well. In my original print, the ring took off some of the layers of the bottom rectangle but since then I have modeled it with more room in between it and the rectangle.
Thanks for checking this out, I think this deserves a print just to check it out.
I didn't have to use any supports but it probably varies printer to printer and depending on how large you scale it. I also use .4mm nozzles.