Printrbot Jr. Upper & Lower Filament Guides (1.75mm)

I was having issues with my filament slipping out of the teeth of the hobbed bolt halfway through a print (Too much twist while unspooling, I guess...). So I came up with a fix that guides the filament directly into the hobbed bot. It also replaces the lasercut piece of wood for the extruder idler, and includes pockets for the nylocks (I hated having to bust out a wrench and a screwdriver to tighten those).

I was also having issues with the lower half of the extruder, it looked like there w