My printer setup required my filament spools to be quite high up above the Tornado's filament feeder, and over time the angle of the filament started to grind away at the plastic guide hole.
So this was my quick fix - an extra little bumper to slot in to the feeder, to prevent the fliament from grinding away the plastic. I'd rather have these little disposable bumpers ground away instead!
OTHER TEVO TORNADO STUFF:
Extruder to bowden tube connecter : https://www.thingiverse.com/thing:3283024