I have been using the minimalistic MK8 on my Replicator for a long time now and it's been perfect so I've converted it into a Bowen extruder. It uses the same bolt pattern for mounting as the airtripper extruder as well as the same bolt retention for the PTFE tubing.

Instructions

Everything is on one build plate and with only 3 printed parts it is about as straight forward as you can get. This extruder is for 1.75mm filament.

It will work without the front plate on just fine and it's not really needed but I included it in case you want to close up the front and support the shaft from the motor. The front plate does have a viewing port so you can see the gear and filament.

This is part of an ongoing project for me to make a Bowden style conversion package for an MK7/8 or qu-bd extruder. I am currently working on the parts for the hot end conversion.

You will need

1 - Nema 17 motor (more power is better)
1 - M4 nut
1 - PTFE tubing with 4mm outside diameter and 2mm inside
2 - M6 bolts and nuts for mounting the extruder
4 - M3 22mm bolts (if not using the cover and 25mm if using the cover.
1 - Spring 1.25"L by .3"W McMaster #9657K331
1 - 10mm OD 3mm ID bearing McMaster #7804K128
1 - M3 10mm flathead
1- MK7 Drive gear from MBI or Raptor Universal Filament Drive Gear from qu-bd

(The file might throw you some errors while slicing it but it still prints just fine)

Category: 3D Printer Extruders