Wall Mount Spool Rack

After reviewing a number of spool holders, I ended up designing my own. For now, wall mounting is the easiest and I ended up on this design: http://www.thingiverse.com/thing:119920. I found it to be overkill structurally even after trimming away most of the volume. I also found this one: http://www.thingiverse.com/thing:513457 but I wanted individual bars for the spools for easier swapping. I came up with this design to make it easy to add more spools since there are not distinct left and ri