A filament holder made from things i had laying around.
I made a spool holder before, but spools with big holes were problematic. I've seen several holder with bearings but they looked like they would need adjusting when switching rolls.
This one have bearings with a paper tube (from a Mentos 6-pack, about 45.5 - 46mm diameter) between them.
I covered the paper tube with some aluminium tape ( http://www.dx.com/p/aluminum-foil-tape-silver-4000-x-5cm-147910 ) to make them look nicer.
I included a filament guide, i have it to keep my sponge from following the filament and getting caught in the extruder gears.