Spool for holding small gauge wires. The spool is comprised of two parts that interconnect with screw threads. I find that the threads print fine with no support at all but using support on the male threads (smaller part) gives it a small amount of stray plastic leftover that adds a little friction which helps hold the two parts together snug.
I added spool stands for both size spools. They can rest on a tabletop or use screws to mount them to the side of something.
NEW! - 7/28/2018 - I created an extendable multi-spool. You can screw them end-to-end to make as many as you wish. I added a photo of two together with red & black wire.