Super simple MendelMax spool support.

thingiverse

To maintain 10 cm and 8 cm wide spools on my MendelMax 1.5, I designed supports. Each support requires an 8 mm M3 socket head bolt, a drop-in nut (http://www.thingiverse.com/thing:245103), and a 15 mm M6 bolt with a 6 mm inner diameter and 17 mm outer diameter ball bearing. They fit tightly in the 20x20 extrusions and could potentially serve other purposes too.