Simple dust remover that fits over standard Makerbot Cupcake CNC Plastruder. Simply print and stick two pieces of Dish washing sponge cut to size with the soft part facing the filament and presto chang-o! Clean filament enters the extruder. You can also fill the sponge with your favorite oil compound for use with PLA.
Skeinforge, ReplicatorG, and print!
Simple design meant to be easy to print with any printer even half way fine tuned. :)