Universal spool holder for square beam (parametric)

NEW VERSION HERE: http://www.thingiverse.com/thing:1070481

This spool holder is using 4 standard 608zz roller/skate ball bearings to limit friction.
Print two supports then insert the bearings onto the pegs. They are designed to hold firmly the bearings. In theory your spool holder is ready but if you plan on using it without the rollers make sure the supports are stable and that the flanges of your spool are exactly parallel (they often are not !) otherwise you will risk a drop and to b