Mk8 Extruder Upgrade Base with filament guide for flexible filament

For use with soft and flexible filament like TPE, PVA, and high-flex PLA. The additional material added to the base will help to constrain the filament so that it does not buckle and jam.

With the modified base, I was able to get around 45 mm/sec with a filament that I previously could not extrude at all.

I made this so that I can work with the existing hardware that I had for the whpthomas design. If you are starting from scratch, you might consider going with the official MBI variant: