Spool Holder - for 2020 T slot extrusion

Here's the design that I used for a top-mounted spool holder for my MendelMax 2.0

You could use these as general rod holders, but I designed them as supports for an M8 rod held between two plates, 20mm apart (to suit 20mm aluminium extrusions)

As usual, here's a link to my blog, with some pictures showing my old spool arrangement and why I went to a top mounted arrangement:
http://teslaandi.wordpress.com/2014/03/01/filament-spool-holder-another-3d-printer-upgrade/

I mounted it in place using 8 of my M5 Twist In Tee Slot Nuts, and it seems to be very stable:
http://www.thingiverse.com/thing:256124

I already had an M8 threaded rod type spool holder from a friend, which I adapted to 3kg my filament spools (~32mm hole, ~200mm outer diameter), using this bearing piece:
http://www.thingiverse.com/thing:22075
You can use whatever 8mm rod filament spool that you want.