My wife needed a way to use larger thread cones on her regular sewing machine.  The reason one would need a thread cone adaptor is: the thread cone, unlike a spool of thread, has a huge hole at the bottom and the tread will not feed evenly into the sewing machine without this adaptor.

Print with any nozzle and layer you like.

I have attached the OpenSCAD mode so you have control of the shape dimension.  The .stl file I provide seems to work with many thread cone sizes.