Prusament Spool Insert

I want  the Prusament spools to sit centered in my drybox, so I've made this insert.

Simply zip-tie it to the spool.

the inner diameter is 9mm to fit on my 8mm rod of my drybox.

Additional bearings caused the spool to untangle because it was too easy to spin. 

Without a bearing, just with the plasitc insert the spool has a small amount of friction but will run pretty smooth.