This is a travel style bobbin for Schacht spinning wheel. It was printed in three separate parts and then glued (super) together. I use both rafts and supports when printing and used 3 layers for the top, bottom, and sides.
I've added a second core file. The first one (solid) is if you want to slice the part and specify the wall thickness. The second file (hollow) has a defined thickness.
A .5mm (radius) tolerance has been subtracted from the hole that the core slides into.
Let me know if there is a different bobbin that you'd like modeled in 3D and I'll see what I can do.