A simple filament guide for Prusa i3 style printer frames (or others) with 5mm thickness.
There is a tight 5mm slot which gives the filament guide a snug fit on top of my i3 Frame.
It's compatible with 3mm and 1.75mm filament.
The locker has curved inside edges so the filament can glide through easily.
Pay attention when printing tall objects the print head may come a bit to close to it..
Hope its helpful!
Locker inspired in http://www.thingiverse.com/thing:1280498
I printed this on a heated bed, with PLA on painters tape using Simplify3D.
Printed 3 walls and layers and %15 infill.