The mendel-parts.com V9 1,75mm Hotend/Extruder works reliable with PLA.Unfortunately 1,75mm ABS filament is softer and more flexible, which can cause some problems.Sometimes the filament bends before entering the hotend tube and curls up between filament drive and hotend.This upgrade solves that problem.1) Configure clearance and hight parameter in scad file, if necessary. 2) Print 3) Drill out holes: Middle hole: 5.9mm - 6.0mm Filament hole: 2.0mm Side 4.0mm - 4.5mm 4) Disassemble Extruder and attach printed part (see photo) 5) Reassemble extruder, make sure, that the side screws can move freely 6) Make sure, that the filament drive can move freely and has enough clearance 7) Post a comment if you have suggestions