Simple spool holder with bearings

This is a remix of my own original simple spool holder ( https://www.thingiverse.com/thing:2704291 ), I wanted to see if I could keep the same shape/function while adding ball bearings to it and to be able to print everything as flat as possible. So here it is :)

It will hold spools down to a 42mm inside hole.
It uses a locking key to keep the spool on it with different positions to accommodate different spool width. The frame also have a couple holes to store the key during spool change.