Just a quick little something i drew up in Illustrator. I was going to glue one of the bearings in to keep it permanent but it fits so tightly that i did not need to. The side in the picture has a sort of ‘puzzle’ shape that i can just slide in place to lock the bearing in place, and pull away to change the filament. A cross piece at the bottom for support and it all works pretty well.
Nice puzzle join!