sea.urchin reoriented

Tried to print the original on my Ender 3 Pro. Watched it wobble and noticed that it only had a little circle of brim, smaller than a quarter. Wouldn't stay in place. Found out it was only touching the baseplate by a very small area on one side. Reoriented it so that it was touching all across the bottom opening. Lost about a millimeter of detail on the bottom but was able to print it. Noted the source file had a wall that was about 1/4" thick, so went back and made it thinner since there was no advantage to the thicker shell for an FDM printer.
Use the 1.5mm shell if you intend to print at this size or larger. I read that sea urchins are typically 1 to 4 inches. A Red Sea urchin can get up to 7 inches but that looks strange to those used to only the smaller sizes.
Use the 2mm shell if you intend to print smaller than this else the shell gets too thin as the model is shrunk.