Summary

Allows printing of 8 to 16 colors of filament without swapping spools, and without using more than 3/4" (yes inch!) of desk space.

Also makes your printer much lighter if you've been mounting filament spools on the back.

Instructions

1) Print one or two 8x filament through holes.
2) Print one to four wall mount filament retainer brackets.
3) Print desired number of filament clips.

4) Drill one (8 colors) or two (16 colors) 3/4" holes below the filament intake of your Replicator (or other 3D printer).

5) Place through hole filament guide into 3/4" hole. For a friction fit, try wrapping with a layer or two of masking tape.

6) Install spools using desired mounting method.

My method: I used 5/8" round dowel covered with 5/8" HDPE tubing (my local brand name is Pex, from Home Depot) which I split down one side so it would snap over the wood dowel. I used some carbon fiber rod to keep the spools from touching each other and from falliing off the dowels. This was glued into holes drilled through the pex and into the round dowel and the appropriate spacing for my spools. I really like the double-length dowels on the left in my picture. They worked very well and hold a lot of filament in a small area.

I drilled some 41/64" (about 16mm) holes into a 2x2 and press fit the round dowels. Mind that the spacing of your holes works for your spool size. The 2x2 is then screwed to the wall or back of cabinet. I installed my at a slightly outward angle so the spools would spin against the carbon stops and not against the 2x2 (less friction).

7) Load up the spool holder with all of your filament. Feed filament from the underside of the spools into the middle (below the 3/4" hole).

8) Install the wall mount filament retainer bracket behind and conveniently above your 3D printer. Route filament from the spools into the guide, and up to the wall mount filament retainer bracket. Clip into place.

9) Print, swap colors, print, swap colors. Enjoy 8CFDS.

http://tinkercad.com/things/81cxG5i5QhV-wall-mount-holder-for-175mm-filament
http://tinkercad.com/things/2OXuqlhHdFY-175mm-8x-filament-guide-through-hole

Eight Color Filament Dispenser System (8CFDS)