This is an updated version of my mod http://www.thingiverse.com/thing:296173 with a lot of new innovation. It can be configured for double sided use to accommodate many different spool sizes using the backers, which screw on with small screws, and can harvested from old filament spools. The foot is designed to strap down with common 1" nylon strap and optionally supports a handle for on-the-go Robo 3D convenience. The handle is 1" schedule 40 PVC pipe which mounts using 1/4-20 bolts. The bed bumper is printed with flexible filament and slides onto your 1" strap.
Also of interest is the optional filament scoop, which acts as a kind of shuttlecock to allow flex in the system. It rides on a 3/16" steel rod, and works very well to deliver smooth, reliable dispensing. Works great with my filament oiler:
http://www.thingiverse.com/thing:1460566
Please post your makes and follow for more Robo 3D mods, coming soon.

Carefully hand thread the bearing spacers. Don't over tighten!

Extra hardware needed:
Standard skatewheel bearings

Optional:
3/16" Steel rod
Small screws for attaching backers and mounting handle interface