About this 3D model

This is a very simple spool holder. It uses 1/2" magnets to attach it to a metalic base (the shelf my printer is on). The rod is a piece of schedule 40 3/4"ID pipe. I don't use a braring of any sort, just rest the spool on the pipe. I've been doingit this way for 6 months now without issue. The magnets I used were these: http://www.rare-earth-magnets.com/p-18-nsn0586.aspx I use a 6-32 1/2" flat-head (countersunk) screw to hold the magents in (though they press fit and that is probably not needed