Update, 2/12/2019 I printed one from PETG, and everything seems to fit well, but the filament seems to slip in the drive gear.

Remixed from:
J-Struder : 1.75mm Bowden Extruder For NEMA 17 Motor
by junaling Sep 8, 2018

I wanted to use a 608 bearing that I had already, with the MK8 hobbed extruder gear.

1 - 2.5 mm x 13 mm bolt with washers to attach the 608 bearing.

I have printed this, but it is untested.

I did run a #50 drill bit through the filament openings to clear them out.

Anet

E10

No

Yes

0.2

50%

Manual supports added under the filament pathway