Sturdier Robo3D Spool Holder

This is modified from a combo of two thingies I found here:
http://www.thingiverse.com/thing:188820
and here:
http://www.thingiverse.com/thing:232391

I'm still not the best with designing my own stuff from scratch, but have (so far) learned enough to mod and combine these two excellent designs to showcase the strength in each.
Namely, the strength of the side supports, with the modular, snap and fit aspects of the other design.

I don't use the "oiler" feature of the original design