Slightly odd but I created a basic bowl shape (imported .svg profile from Illustrator, converted to mesh, spun and exported) but when I exported as an .stl file for 3d printing it registered the shape as 1000 times smaller.
ie .220m in Blender (220mm) became .22mm in the .stl file when I uploaded to a 3d printing service.
I went back and scaled my bowl up to 22m diameter and it came out in the .stl file as 220mm.
So I adjusted my units in Blender to mm and the bowl was too small or at least a real faff to work on.
Is this a glitch or am I being an idiot here?