Filament Refill Spool Holder

This is a spool holder designed for filament refill spools that come on a cardboard tube with an ID of about 82 mm and a width of 60 mm, which I think is standard. There is one variation with a locking nub that interlocks with a cutout in the spool and one without, if your refill happen to not have one.

I've made the two halves screw together and lock in place without requiring a lot of force. 

I suggest printing the threads at a lower layer height so that they work smoothly, I've provided a 3mf file that uses variable layer height.

Print in PLA without supports, around 20% infill, 3 outer perimeters and bump up the top and bottom solid layers to 6. if you want the sides to be a bit stronger.

I've taken some inspiration from this model. Thanks @Emil_1477749!