1KG Twist-Lock Masterspool

I really liked the idea of a twist-lock style master-spool, and after much thinking and searching around found a easily printable method of designing one in 3d-workshop's design. But I needed it in a different size to hold the 1KG refills from filaments.ca. So I made one.

__Update July 7 2018:__
I've uploaded new versions of the hub and side - the key hasn't changed. The locking mechanism is still compatible with the old parts as well, though is a bit stiffer in the new ones. The outside