I really like:
- low profile of a spool roller vs tall holder
- ability to quickly switch out spools no center rods no nuts to unscrew
I couldn't find a roller for my Anet A8 like the one for the Prusa I3 Mk2 by MartinMajewski http://www.thingiverse.com/thing:1832235
So I modified his arm to fit the Anet A8 frame and designed it in a way to hold multiple spools with just two printed arms.
Things you need to complete the setup:
1) 2 x rods, I used carbon fiber rods 7.8mm diameter ~27cm+ length
2) 4 x Martin's rollers that you'll need to print from thing 1832235
3) 4 x 608 (skater) bearings like these https://www.amazon.ca/gp/product/B00MM1FFUK
Edit: I've just added a Filament Guide / Filter to work perfectly with this Holder. Check it out http://www.thingiverse.com/thing:2256538
You may need to drill out the holes a bit to fit the rod.