Summary The original version of this very cool filament guide is too big! The base doesn't even remotely fit inside the hexagon hole at the top of the Original Prusa i3 MK2 Z axis top. I think maybe they printed it in ABS and just expected shrinkage? Anyway, this version has the actual correct dimensions for printing and fitting inside the Original Prusa i3 MK2 Z axis top. I also added a little lip to ensure it doesn't protrude too far down and interfere with the Z axis. Print and enjoy his bendiness! Tip: Print with a 4mm brim so it doesn't topple over while printing.