Makerbot MK8 1.75mm Filament all-Metal Bowden Extruder Wire feeder Ultimate Upgrade

thingiverse

Filament guide and cylindrical insert for my upgrade of metal MK8 extruder from ebay. Upgrade is created for bowden print - in my case for E3D Kraken. My simple upgrade adds the power of the stepper motor and allows large retraction of the filament. ​I recently bought all-metal ​Makerbot ​MK8 bowden extruders - feeders - for my multihead printer . After completing and plugging the stepper motor (which powered my old 3D printed extruder until now:​ https://www.thingiverse.com/thing:1132201​) I found out that my 60NM stepper motor can not push the filament. I realized that the stepper motor loses its strength due to the large diameter of the drive gear pulley (11mm). First step is to replace the original gear pulley for a smaler gear pulley (9mm outside diameter and 7.5mm effective diameter in the groove for filament). The next step is to replace the small pressure bearing for a large diameter 608ZZ bearing (small diameter of the bearing deforms filament and, in the case of use retractions, also tears it). Aluminum bearing attachment must be enlarged by grinding. (for more informations search on www.instructables.com for: MK8 Metal Bowden Extruder Wire Feeder Ultimate Upgrade) I am sorry for my english ;)